diff --git a/packages/eslint-plugin/tests/rules/no-empty-object-type.test.ts b/packages/eslint-plugin/tests/rules/no-empty-object-type.test.ts
index 6494b8d6372f..ec418d10d249 100644
--- a/packages/eslint-plugin/tests/rules/no-empty-object-type.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-empty-object-type.test.ts
@@ -546,6 +546,16 @@ let value: unknown;
           endColumn: 15,
           endLine: 1,
           messageId: 'noEmptyObject',
+          suggestions: [
+            {
+              messageId: 'replaceEmptyObjectType',
+              output: 'type Base = object | null;',
+            },
+            {
+              messageId: 'replaceEmptyObjectType',
+              output: 'type Base = unknown | null;',
+            },
+          ],
         },
       ],
       options: [{ allowWithName: 'Base' }],
@@ -559,6 +569,16 @@ let value: unknown;
           endColumn: 15,
           endLine: 1,
           messageId: 'noEmptyObject',
+          suggestions: [
+            {
+              messageId: 'replaceEmptyObjectType',
+              output: 'type Base = object;',
+            },
+            {
+              messageId: 'replaceEmptyObjectType',
+              output: 'type Base = unknown;',
+            },
+          ],
         },
       ],
       options: [{ allowWithName: 'Mismatch' }],
diff --git a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
index e6087e512265..4911e944b64d 100644
--- a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
@@ -749,18 +749,70 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void Promise.resolve('value');
+  Promise.resolve('value').then(() => {});
+  Promise.resolve('value').catch();
+  Promise.resolve('value').finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.resolve('value');
+  void Promise.resolve('value').then(() => {});
+  Promise.resolve('value').catch();
+  Promise.resolve('value').finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.resolve('value');
+  Promise.resolve('value').then(() => {});
+  void Promise.resolve('value').catch();
+  Promise.resolve('value').finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 6,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.resolve('value');
+  Promise.resolve('value').then(() => {});
+  Promise.resolve('value').catch();
+  void Promise.resolve('value').finally();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -791,34 +843,250 @@ doSomething();
         {
           line: 11,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  void obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 12,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  void obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 13,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  void obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 14,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  void obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 15,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  void obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 16,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  void obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 18,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  void callback?.();
+};
+
+doSomething();
+      `,
+            },
+          ],
         },
         {
           line: 21,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const doSomething = async (
+  obj1: { a?: { b?: { c?: () => Promise<void> } } },
+  obj2: { a?: { b?: { c: () => Promise<void> } } },
+  obj3: { a?: { b: { c?: () => Promise<void> } } },
+  obj4: { a: { b: { c?: () => Promise<void> } } },
+  obj5: { a?: () => { b?: { c?: () => Promise<void> } } },
+  obj6?: { a: { b: { c?: () => Promise<void> } } },
+  callback?: () => Promise<void>,
+): Promise<void> => {
+  obj1.a?.b?.c?.();
+  obj2.a?.b?.c();
+  obj3.a?.b.c?.();
+  obj4.a.b.c?.();
+  obj5.a?.().b?.c?.();
+  obj6?.a.b.c?.();
+
+  callback?.();
+};
+
+void doSomething();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -831,6 +1099,15 @@ myTag\`abc\`;
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const myTag: (strings: TemplateStringsArray) => Promise<void>;
+void myTag\`abc\`;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -843,6 +1120,15 @@ myTag\`abc\`.then(() => {});
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const myTag: (strings: TemplateStringsArray) => Promise<void>;
+void myTag\`abc\`.then(() => {});
+      `,
+            },
+          ],
         },
       ],
     },
@@ -855,6 +1141,15 @@ myTag\`abc\`.finally(() => {});
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const myTag: (strings: TemplateStringsArray) => Promise<void>;
+void myTag\`abc\`.finally(() => {});
+      `,
+            },
+          ],
         },
       ],
     },
@@ -889,25 +1184,77 @@ async function test() {
   Promise.reject(new Error('message'));
   Promise.reject(new Error('message')).then(() => {});
   Promise.reject(new Error('message')).catch();
-  Promise.reject(new Error('message')).finally();
+  Promise.reject(new Error('message')).finally();
+}
+      `,
+      errors: [
+        {
+          line: 3,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void Promise.reject(new Error('message'));
+  Promise.reject(new Error('message')).then(() => {});
+  Promise.reject(new Error('message')).catch();
+  Promise.reject(new Error('message')).finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.reject(new Error('message'));
+  void Promise.reject(new Error('message')).then(() => {});
+  Promise.reject(new Error('message')).catch();
+  Promise.reject(new Error('message')).finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 5,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.reject(new Error('message'));
+  Promise.reject(new Error('message')).then(() => {});
+  void Promise.reject(new Error('message')).catch();
+  Promise.reject(new Error('message')).finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 6,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.reject(new Error('message'));
+  Promise.reject(new Error('message')).then(() => {});
+  Promise.reject(new Error('message')).catch();
+  void Promise.reject(new Error('message')).finally();
 }
       `,
-      errors: [
-        {
-          line: 3,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 4,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 5,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 6,
-          messageId: 'floatingVoid',
+            },
+          ],
         },
       ],
     },
@@ -923,14 +1270,50 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void (async () => true)();
+  (async () => true)().then(() => {});
+  (async () => true)().catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  (async () => true)();
+  void (async () => true)().then(() => {});
+  (async () => true)().catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  (async () => true)();
+  (async () => true)().then(() => {});
+  void (async () => true)().catch();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -949,18 +1332,78 @@ async function test() {
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  async function returnsPromise() {}
+
+  void returnsPromise();
+  returnsPromise().then(() => {});
+  returnsPromise().catch();
+  returnsPromise().finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 6,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  async function returnsPromise() {}
+
+  returnsPromise();
+  void returnsPromise().then(() => {});
+  returnsPromise().catch();
+  returnsPromise().finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 7,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  async function returnsPromise() {}
+
+  returnsPromise();
+  returnsPromise().then(() => {});
+  void returnsPromise().catch();
+  returnsPromise().finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 8,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  async function returnsPromise() {}
+
+  returnsPromise();
+  returnsPromise().then(() => {});
+  returnsPromise().catch();
+  void returnsPromise().finally();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -975,10 +1418,32 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void (Math.random() > 0.5 ? Promise.resolve() : null);
+  Math.random() > 0.5 ? null : Promise.resolve();
+}
+      `,
+            },
+          ],
         },
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Math.random() > 0.5 ? Promise.resolve() : null;
+  void (Math.random() > 0.5 ? null : Promise.resolve());
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -994,14 +1459,50 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void (Promise.resolve(), 123);
+  123, Promise.resolve();
+  123, Promise.resolve(), 123;
+}
+      `,
+            },
+          ],
         },
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.resolve(), 123;
+  void (123, Promise.resolve());
+  123, Promise.resolve(), 123;
+}
+      `,
+            },
+          ],
         },
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  Promise.resolve(), 123;
+  123, Promise.resolve();
+  void (123, Promise.resolve(), 123);
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1171,6 +1672,17 @@ async function test() {
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  const obj = { foo: Promise.resolve() };
+  void obj.foo;
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1184,36 +1696,106 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
-        },
-      ],
-    },
-    {
-      code: `
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  void new Promise(resolve => resolve());
+}
+      `,
+            },
+          ],
+        },
+      ],
+    },
+    {
+      code: `
+async function test() {
+  declare const promiseValue: Promise<number>;
+
+  promiseValue;
+  promiseValue.then(() => {});
+  promiseValue.catch();
+  promiseValue.finally();
+}
+      `,
+      errors: [
+        {
+          line: 5,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseValue: Promise<number>;
+
+  void promiseValue;
+  promiseValue.then(() => {});
+  promiseValue.catch();
+  promiseValue.finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 6,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseValue: Promise<number>;
+
+  promiseValue;
+  void promiseValue.then(() => {});
+  promiseValue.catch();
+  promiseValue.finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 7,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseValue: Promise<number>;
+
+  promiseValue;
+  promiseValue.then(() => {});
+  void promiseValue.catch();
+  promiseValue.finally();
+}
+      `,
+            },
+          ],
+        },
+        {
+          line: 8,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
 async function test() {
   declare const promiseValue: Promise<number>;
 
   promiseValue;
   promiseValue.then(() => {});
   promiseValue.catch();
-  promiseValue.finally();
+  void promiseValue.finally();
 }
       `,
-      errors: [
-        {
-          line: 5,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 6,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 7,
-          messageId: 'floatingVoid',
-        },
-        {
-          line: 8,
-          messageId: 'floatingVoid',
+            },
+          ],
         },
       ],
     },
@@ -1229,6 +1811,18 @@ async function test() {
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseUnion: Promise<number> | number;
+
+  void promiseUnion;
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1246,14 +1840,56 @@ async function test() {
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseIntersection: Promise<number> & number;
+
+  void promiseIntersection;
+  promiseIntersection.then(() => {});
+  promiseIntersection.catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 6,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseIntersection: Promise<number> & number;
+
+  promiseIntersection;
+  void promiseIntersection.then(() => {});
+  promiseIntersection.catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 7,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  declare const promiseIntersection: Promise<number> & number;
+
+  promiseIntersection;
+  promiseIntersection.then(() => {});
+  void promiseIntersection.catch();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1273,18 +1909,82 @@ async function test() {
         {
           line: 6,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CanThen extends Promise<number> {}
+  const canThen: CanThen = Foo.resolve(2);
+
+  void canThen;
+  canThen.then(() => {});
+  canThen.catch();
+  canThen.finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 7,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CanThen extends Promise<number> {}
+  const canThen: CanThen = Foo.resolve(2);
+
+  canThen;
+  void canThen.then(() => {});
+  canThen.catch();
+  canThen.finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 8,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CanThen extends Promise<number> {}
+  const canThen: CanThen = Foo.resolve(2);
+
+  canThen;
+  canThen.then(() => {});
+  void canThen.catch();
+  canThen.finally();
+}
+      `,
+            },
+          ],
         },
         {
           line: 9,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CanThen extends Promise<number> {}
+  const canThen: CanThen = Foo.resolve(2);
+
+  canThen;
+  canThen.then(() => {});
+  canThen.catch();
+  void canThen.finally();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1306,10 +2006,46 @@ async function test() {
         {
           line: 10,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CatchableThenable {
+    then(callback: () => void, callback: () => void): CatchableThenable {
+      return new CatchableThenable();
+    }
+  }
+  const thenable = new CatchableThenable();
+
+  void thenable;
+  thenable.then(() => {});
+}
+      `,
+            },
+          ],
         },
         {
           line: 11,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function test() {
+  class CatchableThenable {
+    then(callback: () => void, callback: () => void): CatchableThenable {
+      return new CatchableThenable();
+    }
+  }
+  const thenable = new CatchableThenable();
+
+  thenable;
+  void thenable.then(() => {});
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1340,14 +2076,95 @@ async function test() {
         {
           line: 18,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+// https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/promise-polyfill/index.d.ts
+// Type definitions for promise-polyfill 6.0
+// Project: https://github.com/taylorhakes/promise-polyfill
+// Definitions by: Steve Jenkins <https://github.com/skysteve>
+//                 Daniel Cassidy <https://github.com/djcsdy>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+interface PromisePolyfillConstructor extends PromiseConstructor {
+  _immediateFn?: (handler: (() => void) | string) => void;
+}
+
+declare const PromisePolyfill: PromisePolyfillConstructor;
+
+async function test() {
+  const promise = new PromisePolyfill(() => {});
+
+  void promise;
+  promise.then(() => {});
+  promise.catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 19,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+// https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/promise-polyfill/index.d.ts
+// Type definitions for promise-polyfill 6.0
+// Project: https://github.com/taylorhakes/promise-polyfill
+// Definitions by: Steve Jenkins <https://github.com/skysteve>
+//                 Daniel Cassidy <https://github.com/djcsdy>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+interface PromisePolyfillConstructor extends PromiseConstructor {
+  _immediateFn?: (handler: (() => void) | string) => void;
+}
+
+declare const PromisePolyfill: PromisePolyfillConstructor;
+
+async function test() {
+  const promise = new PromisePolyfill(() => {});
+
+  promise;
+  void promise.then(() => {});
+  promise.catch();
+}
+      `,
+            },
+          ],
         },
         {
           line: 20,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+// https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/promise-polyfill/index.d.ts
+// Type definitions for promise-polyfill 6.0
+// Project: https://github.com/taylorhakes/promise-polyfill
+// Definitions by: Steve Jenkins <https://github.com/skysteve>
+//                 Daniel Cassidy <https://github.com/djcsdy>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+interface PromisePolyfillConstructor extends PromiseConstructor {
+  _immediateFn?: (handler: (() => void) | string) => void;
+}
+
+declare const PromisePolyfill: PromisePolyfillConstructor;
+
+async function test() {
+  const promise = new PromisePolyfill(() => {});
+
+  promise;
+  promise.then(() => {});
+  void promise.catch();
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1361,6 +2178,16 @@ async function test() {
         {
           line: 2,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        void (async () => {
+          await something();
+        })();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1374,6 +2201,16 @@ async function test() {
         {
           line: 2,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        void (async () => {
+          something();
+        })();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1383,6 +2220,12 @@ async function test() {
         {
           line: 1,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: 'void (async function foo() {})();',
+            },
+          ],
         },
       ],
     },
@@ -1396,6 +2239,16 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        function foo() {
+          void (async function bar() {})();
+        }
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1412,6 +2265,19 @@ async function test() {
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        const foo = () =>
+          new Promise(res => {
+            void (async function () {
+              await res(1);
+            })();
+          });
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1425,6 +2291,16 @@ async function test() {
         {
           line: 2,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        void (async function () {
+          await res(1);
+        })();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1439,6 +2315,16 @@ async function test() {
         {
           line: 3,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        (async function () {
+          void Promise.resolve();
+        })();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1457,18 +2343,74 @@ async function test() {
         {
           line: 4,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        (async function () {
+          declare const promiseIntersection: Promise<number> & number;
+          void promiseIntersection;
+          promiseIntersection.then(() => {});
+          promiseIntersection.catch();
+          promiseIntersection.finally();
+        })();
+      `,
+            },
+          ],
         },
         {
           line: 5,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        (async function () {
+          declare const promiseIntersection: Promise<number> & number;
+          promiseIntersection;
+          void promiseIntersection.then(() => {});
+          promiseIntersection.catch();
+          promiseIntersection.finally();
+        })();
+      `,
+            },
+          ],
         },
         {
           line: 6,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        (async function () {
+          declare const promiseIntersection: Promise<number> & number;
+          promiseIntersection;
+          promiseIntersection.then(() => {});
+          void promiseIntersection.catch();
+          promiseIntersection.finally();
+        })();
+      `,
+            },
+          ],
         },
         {
           line: 7,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+        (async function () {
+          declare const promiseIntersection: Promise<number> & number;
+          promiseIntersection;
+          promiseIntersection.then(() => {});
+          promiseIntersection.catch();
+          void promiseIntersection.finally();
+        })();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1711,28 +2653,194 @@ async function foo() {
   condition || condition || myPromise();
 }
       `,
-      errors: [
+      errors: [
+        {
+          line: 6,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+async function foo() {
+  const myPromise = async () => void 0;
+  const condition = false;
+
+  void (condition || condition || myPromise());
+}
+      `,
+            },
+          ],
+        },
+      ],
+    },
+    {
+      code: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+void Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
+        },
+        {
+          line: 5,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+void Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
+        },
+        {
+          line: 6,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+void Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
+        },
+        {
+          line: 7,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+void Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
+        },
+        {
+          line: 10,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+void Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
+        },
         {
-          line: 6,
-          messageId: 'floatingVoid',
+          line: 11,
+          messageId: 'floatingUselessRejectionHandlerVoid',
           suggestions: [
             {
               messageId: 'floatingFixVoid',
               output: `
-async function foo() {
-  const myPromise = async () => void 0;
-  const condition = false;
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
 
-  void (condition || condition || myPromise());
-}
+Promise.resolve().catch(undefined);
+void Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
       `,
             },
           ],
         },
-      ],
-    },
-    {
-      code: `
+        {
+          line: 12,
+          messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
 declare const maybeCallable: string | (() => void);
 declare const definitelyCallable: () => void;
 Promise.resolve().then(() => {}, undefined);
@@ -1743,42 +2851,36 @@ Promise.resolve().then(() => {}, definitelyCallable);
 
 Promise.resolve().catch(undefined);
 Promise.resolve().catch(null);
-Promise.resolve().catch(3);
+void Promise.resolve().catch(3);
 Promise.resolve().catch(maybeCallable);
 Promise.resolve().catch(definitelyCallable);
       `,
-      errors: [
-        {
-          line: 4,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 5,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 6,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 7,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 10,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 11,
-          messageId: 'floatingUselessRejectionHandlerVoid',
-        },
-        {
-          line: 12,
-          messageId: 'floatingUselessRejectionHandlerVoid',
+            },
+          ],
         },
         {
           line: 13,
           messageId: 'floatingUselessRejectionHandlerVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+void Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1790,6 +2892,14 @@ Promise.reject() || 3;
         {
           line: 2,
           messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void (Promise.reject() || 3);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1802,6 +2912,14 @@ void Promise.resolve().then(() => {}, undefined);
         {
           line: 2,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+await Promise.resolve().then(() => {}, undefined);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1815,6 +2933,15 @@ Promise.resolve().then(() => {}, maybeCallable);
         {
           line: 3,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+await Promise.resolve().then(() => {}, maybeCallable);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1839,34 +2966,194 @@ Promise.resolve().catch(definitelyCallable);
         {
           line: 4,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+await Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 5,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+await Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 6,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+await Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 7,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+await Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 10,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+await Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 11,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+await Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 12,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+await Promise.resolve().catch(3);
+Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
         {
           line: 13,
           messageId: 'floatingUselessRejectionHandler',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+declare const maybeCallable: string | (() => void);
+declare const definitelyCallable: () => void;
+Promise.resolve().then(() => {}, undefined);
+Promise.resolve().then(() => {}, null);
+Promise.resolve().then(() => {}, 3);
+Promise.resolve().then(() => {}, maybeCallable);
+Promise.resolve().then(() => {}, definitelyCallable);
+
+Promise.resolve().catch(undefined);
+Promise.resolve().catch(null);
+Promise.resolve().catch(3);
+await Promise.resolve().catch(maybeCallable);
+Promise.resolve().catch(definitelyCallable);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1879,6 +3166,14 @@ Promise.reject() || 3;
         {
           line: 2,
           messageId: 'floating',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+await (Promise.reject() || 3);
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1886,7 +3181,20 @@ Promise.reject() || 3;
       code: `
 Promise.reject().finally(() => {});
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void Promise.reject().finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1895,7 +3203,22 @@ Promise.reject()
   .finally(() => {});
       `,
       options: [{ ignoreVoid: false }],
-      errors: [{ line: 2, messageId: 'floating' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floating',
+          suggestions: [
+            {
+              messageId: 'floatingFixAwait',
+              output: `
+await Promise.reject()
+  .finally(() => {})
+  .finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1904,7 +3227,23 @@ Promise.reject()
   .finally(() => {})
   .finally(() => {});
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void Promise.reject()
+  .finally(() => {})
+  .finally(() => {})
+  .finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1912,39 +3251,121 @@ Promise.reject()
   .then(() => {})
   .finally(() => {});
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void Promise.reject()
+  .then(() => {})
+  .finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
 declare const returnsPromise: () => Promise<void> | null;
 returnsPromise()?.finally(() => {});
       `,
-      errors: [{ line: 3, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 3,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+declare const returnsPromise: () => Promise<void> | null;
+void returnsPromise()?.finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
 const promiseIntersection: Promise<number> & number;
 promiseIntersection.finally(() => {});
       `,
-      errors: [{ line: 3, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 3,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+const promiseIntersection: Promise<number> & number;
+void promiseIntersection.finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
 Promise.resolve().finally(() => {}), 123;
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void (Promise.resolve().finally(() => {}), 123);
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
 (async () => true)().finally();
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void (async () => true)().finally();
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
 Promise.reject(new Error('message')).finally(() => {});
       `,
-      errors: [{ line: 2, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 2,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+void Promise.reject(new Error('message')).finally(() => {});
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1954,7 +3375,24 @@ function _<T, S extends Array<T | Promise<T>>>(
   maybePromiseArray?.[0];
 }
       `,
-      errors: [{ line: 5, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 5,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+function _<T, S extends Array<T | Promise<T>>>(
+  maybePromiseArray: S | undefined,
+): void {
+  void maybePromiseArray?.[0];
+}
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2094,7 +3532,33 @@ promise;
           allowForKnownSafePromises: [{ from: 'file', name: 'SafeThenable' }],
         },
       ],
-      errors: [{ line: 15, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 15,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+interface UnsafeThenable<T> {
+  then<TResult1 = T, TResult2 = never>(
+    onfulfilled?:
+      | ((value: T) => TResult1 | UnsafeThenable<TResult1>)
+      | undefined
+      | null,
+    onrejected?:
+      | ((reason: any) => TResult2 | UnsafeThenable<TResult2>)
+      | undefined
+      | null,
+  ): UnsafeThenable<TResult1 | TResult2>;
+}
+let promise: UnsafeThenable<number> = Promise.resolve(5);
+void promise;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2105,7 +3569,22 @@ promise.catch();
       options: [
         { allowForKnownSafePromises: [{ from: 'file', name: 'SafePromise' }] },
       ],
-      errors: [{ line: 4, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+class SafePromise<T> extends Promise<T> {}
+let promise: SafePromise<number> = Promise.resolve(5);
+void promise.catch();
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2116,7 +3595,22 @@ promise().finally();
       options: [
         { allowForKnownSafePromises: [{ from: 'file', name: 'SafePromise' }] },
       ],
-      errors: [{ line: 4, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+class UnsafePromise<T> extends Promise<T> {}
+let promise: () => UnsafePromise<number> = async () => 5;
+void promise().finally();
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2127,7 +3621,22 @@ let promise: UnsafePromise = Promise.resolve(5);
       options: [
         { allowForKnownSafePromises: [{ from: 'file', name: 'SafePromise' }] },
       ],
-      errors: [{ line: 4, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+type UnsafePromise = Promise<number> & { hey?: string };
+let promise: UnsafePromise = Promise.resolve(5);
+void (0 ? promise.catch() : 2);
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2138,7 +3647,22 @@ null ?? promise().catch();
       options: [
         { allowForKnownSafePromises: [{ from: 'file', name: 'SafePromise' }] },
       ],
-      errors: [{ line: 4, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+type UnsafePromise = Promise<number> & { hey?: string };
+let promise: () => UnsafePromise = async () => 5;
+void (null ?? promise().catch());
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -2179,7 +3703,22 @@ declare const myTag: (strings: TemplateStringsArray) => SafePromise;
 myTag\`abc\`;
       `,
       options: [{ allowForKnownSafePromises: [{ from: 'file', name: 'Foo' }] }],
-      errors: [{ line: 4, messageId: 'floatingVoid' }],
+      errors: [
+        {
+          line: 4,
+          messageId: 'floatingVoid',
+          suggestions: [
+            {
+              messageId: 'floatingFixVoid',
+              output: `
+type SafePromise = Promise<number> & { __linterBrands?: string };
+declare const myTag: (strings: TemplateStringsArray) => SafePromise;
+void myTag\`abc\`;
+      `,
+            },
+          ],
+        },
+      ],
     },
   ],
 });
diff --git a/packages/eslint-plugin/tests/rules/no-unsafe-enum-comparison.test.ts b/packages/eslint-plugin/tests/rules/no-unsafe-enum-comparison.test.ts
index b2d4eb907b33..9a7f49dc3ecc 100644
--- a/packages/eslint-plugin/tests/rules/no-unsafe-enum-comparison.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unsafe-enum-comparison.test.ts
@@ -409,7 +409,23 @@ ruleTester.run('strict-enums-comparison', rule, {
         }
         Fruit.Apple === 0;
       `,
-      errors: [{ messageId: 'mismatchedCondition' }],
+      errors: [
+        {
+          messageId: 'mismatchedCondition',
+          suggestions: [
+            {
+              messageId: 'replaceValueWithEnum',
+              output: `
+        enum Fruit {
+          Apple = 0,
+          Banana = 'banana',
+        }
+        Fruit.Apple === Fruit.Apple;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -584,10 +600,126 @@ ruleTester.run('strict-enums-comparison', rule, {
         mixed === 1;
       `,
       errors: [
-        { messageId: 'mismatchedCondition' },
-        { messageId: 'mismatchedCondition' },
-        { messageId: 'mismatchedCondition' },
-        { messageId: 'mismatchedCondition' },
+        {
+          messageId: 'mismatchedCondition',
+          suggestions: [
+            {
+              messageId: 'replaceValueWithEnum',
+              output: `
+        enum Str {
+          A = 'a',
+        }
+        enum Num {
+          B = 1,
+        }
+        enum Mixed {
+          A = 'a',
+          B = 1,
+        }
+
+        declare const str: Str;
+        declare const num: Num;
+        declare const mixed: Mixed;
+
+        // following are all errors because the value might be an enum value
+        str === Str.A;
+        num === 1;
+        mixed === 'a';
+        mixed === 1;
+      `,
+            },
+          ],
+        },
+        {
+          messageId: 'mismatchedCondition',
+          suggestions: [
+            {
+              messageId: 'replaceValueWithEnum',
+              output: `
+        enum Str {
+          A = 'a',
+        }
+        enum Num {
+          B = 1,
+        }
+        enum Mixed {
+          A = 'a',
+          B = 1,
+        }
+
+        declare const str: Str;
+        declare const num: Num;
+        declare const mixed: Mixed;
+
+        // following are all errors because the value might be an enum value
+        str === 'a';
+        num === Num.B;
+        mixed === 'a';
+        mixed === 1;
+      `,
+            },
+          ],
+        },
+        {
+          messageId: 'mismatchedCondition',
+          suggestions: [
+            {
+              messageId: 'replaceValueWithEnum',
+              output: `
+        enum Str {
+          A = 'a',
+        }
+        enum Num {
+          B = 1,
+        }
+        enum Mixed {
+          A = 'a',
+          B = 1,
+        }
+
+        declare const str: Str;
+        declare const num: Num;
+        declare const mixed: Mixed;
+
+        // following are all errors because the value might be an enum value
+        str === 'a';
+        num === 1;
+        mixed === Mixed.A;
+        mixed === 1;
+      `,
+            },
+          ],
+        },
+        {
+          messageId: 'mismatchedCondition',
+          suggestions: [
+            {
+              messageId: 'replaceValueWithEnum',
+              output: `
+        enum Str {
+          A = 'a',
+        }
+        enum Num {
+          B = 1,
+        }
+        enum Mixed {
+          A = 'a',
+          B = 1,
+        }
+
+        declare const str: Str;
+        declare const num: Num;
+        declare const mixed: Mixed;
+
+        // following are all errors because the value might be an enum value
+        str === 'a';
+        num === 1;
+        mixed === 'a';
+        mixed === Mixed.B;
+      `,
+            },
+          ],
+        },
       ],
     },
     {
diff --git a/packages/eslint-plugin/tests/rules/prefer-as-const.test.ts b/packages/eslint-plugin/tests/rules/prefer-as-const.test.ts
index 19058d692b42..e0c917c88f21 100644
--- a/packages/eslint-plugin/tests/rules/prefer-as-const.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-as-const.test.ts
@@ -121,6 +121,12 @@ ruleTester.run('prefer-as-const', rule, {
           messageId: 'variableConstAssertion',
           line: 1,
           column: 9,
+          suggestions: [
+            {
+              messageId: 'variableSuggest',
+              output: "let [] = 'bar' as const;",
+            },
+          ],
         },
       ],
     },
diff --git a/packages/eslint-plugin/tests/rules/prefer-nullish-coalescing.test.ts b/packages/eslint-plugin/tests/rules/prefer-nullish-coalescing.test.ts
index 5affe9874a50..bd0cd13c4b5a 100644
--- a/packages/eslint-plugin/tests/rules/prefer-nullish-coalescing.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-nullish-coalescing.test.ts
@@ -957,7 +957,20 @@ x || y;
           ignorePrimitives: { number: true, boolean: true, bigint: true },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: string | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -970,7 +983,20 @@ x || y;
           ignorePrimitives: { string: true, boolean: true, bigint: true },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: number | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -983,7 +1009,20 @@ x || y;
           ignorePrimitives: { string: true, number: true, bigint: true },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: boolean | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -996,7 +1035,20 @@ x || y;
           ignorePrimitives: { string: true, number: true, boolean: true },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: bigint | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     // falsy
     {
@@ -1015,7 +1067,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: '' | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1033,7 +1098,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: \`\` | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1051,7 +1129,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 0 | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1069,7 +1160,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 0n | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1087,7 +1191,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: false | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     // truthy
     {
@@ -1106,7 +1223,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 'a' | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1124,7 +1254,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: \`hello\${'string'}\` | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1142,7 +1285,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 1 | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1160,7 +1316,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 1n | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1178,7 +1347,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: true | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     // Unions of same primitive
     {
@@ -1197,7 +1379,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 'a' | 'b' | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1215,7 +1410,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 'a' | \`b\` | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1233,7 +1441,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 0 | 1 | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1251,7 +1472,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 1 | 2 | 3 | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1269,7 +1503,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 0n | 1n | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1287,7 +1534,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 1n | 2n | 3n | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1305,7 +1565,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: true | false | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     // Mixed unions
     {
@@ -1324,7 +1597,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: 0 | 1 | 0n | 1n | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1342,7 +1628,20 @@ x || y;
           },
         },
       ],
-      errors: [{ messageId: 'preferNullishOverOr' }],
+      errors: [
+        {
+          messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: true | false | null | undefined;
+x ?? y;
+      `,
+            },
+          ],
+        },
+      ],
     },
     {
       code: `
@@ -1353,6 +1652,15 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+declare const x: null;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1365,6 +1673,15 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+const x = undefined;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1376,6 +1693,14 @@ null || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+null ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1387,6 +1712,14 @@ undefined || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+undefined ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1404,6 +1737,20 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+enum Enum {
+  A = 0,
+  B = 1,
+  C = 2,
+}
+declare const x: Enum | undefined;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1421,6 +1768,20 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+enum Enum {
+  A = 0,
+  B = 1,
+  C = 2,
+}
+declare const x: Enum.A | Enum.B | undefined;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1438,6 +1799,20 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+enum Enum {
+  A = 'a',
+  B = 'b',
+  C = 'c',
+}
+declare const x: Enum | undefined;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1455,6 +1830,20 @@ x || y;
       errors: [
         {
           messageId: 'preferNullishOverOr',
+          suggestions: [
+            {
+              messageId: 'suggestNullish',
+              output: `
+enum Enum {
+  A = 'a',
+  B = 'b',
+  C = 'c',
+}
+declare const x: Enum.A | Enum.B | undefined;
+x ?? y;
+      `,
+            },
+          ],
         },
       ],
     },
diff --git a/packages/eslint-plugin/tests/rules/strict-boolean-expressions.test.ts b/packages/eslint-plugin/tests/rules/strict-boolean-expressions.test.ts
index bd25e35fe136..dd1bb0a92a38 100644
--- a/packages/eslint-plugin/tests/rules/strict-boolean-expressions.test.ts
+++ b/packages/eslint-plugin/tests/rules/strict-boolean-expressions.test.ts
@@ -523,9 +523,49 @@ if (y) {
       code: "'asd' && 123 && [] && null;",
       output: null,
       errors: [
-        { messageId: 'conditionErrorString', line: 1, column: 1 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 10 },
-        { messageId: 'conditionErrorObject', line: 1, column: 17 },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 1,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output: "('asd'.length > 0) && 123 && [] && null;",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: '(\'asd\' !== "") && 123 && [] && null;',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "(Boolean('asd')) && 123 && [] && null;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 10,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "'asd' && (123 !== 0) && [] && null;",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output: "'asd' && (!Number.isNaN(123)) && [] && null;",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "'asd' && (Boolean(123)) && [] && null;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 17,
+        },
       ],
     },
     {
@@ -533,9 +573,49 @@ if (y) {
       code: "'asd' || 123 || [] || null;",
       output: null,
       errors: [
-        { messageId: 'conditionErrorString', line: 1, column: 1 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 10 },
-        { messageId: 'conditionErrorObject', line: 1, column: 17 },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 1,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output: "('asd'.length > 0) || 123 || [] || null;",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: '(\'asd\' !== "") || 123 || [] || null;',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "(Boolean('asd')) || 123 || [] || null;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 10,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "'asd' || (123 !== 0) || [] || null;",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output: "'asd' || (!Number.isNaN(123)) || [] || null;",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "'asd' || (Boolean(123)) || [] || null;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 17,
+        },
       ],
     },
     {
@@ -543,11 +623,91 @@ if (y) {
       code: "let x = (1 && 'a' && null) || 0 || '' || {};",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNumber', line: 1, column: 10 },
-        { messageId: 'conditionErrorString', line: 1, column: 15 },
-        { messageId: 'conditionErrorNullish', line: 1, column: 22 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 31 },
-        { messageId: 'conditionErrorString', line: 1, column: 36 },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 10,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "let x = ((1 !== 0) && 'a' && null) || 0 || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output:
+                "let x = ((!Number.isNaN(1)) && 'a' && null) || 0 || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "let x = ((Boolean(1)) && 'a' && null) || 0 || '' || {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 15,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output:
+                "let x = (1 && ('a'.length > 0) && null) || 0 || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: "let x = (1 && ('a' !== \"\") && null) || 0 || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "let x = (1 && (Boolean('a')) && null) || 0 || '' || {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorNullish',
+          line: 1,
+          column: 22,
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 31,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "let x = (1 && 'a' && null) || (0 !== 0) || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output:
+                "let x = (1 && 'a' && null) || (!Number.isNaN(0)) || '' || {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "let x = (1 && 'a' && null) || (Boolean(0)) || '' || {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 36,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output:
+                "let x = (1 && 'a' && null) || 0 || (''.length > 0) || {};",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: "let x = (1 && 'a' && null) || 0 || ('' !== \"\") || {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "let x = (1 && 'a' && null) || 0 || (Boolean('')) || {};",
+            },
+          ],
+        },
       ],
     },
     {
@@ -555,11 +715,91 @@ if (y) {
       code: "return (1 || 'a' || null) && 0 && '' && {};",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNumber', line: 1, column: 9 },
-        { messageId: 'conditionErrorString', line: 1, column: 14 },
-        { messageId: 'conditionErrorNullish', line: 1, column: 21 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 30 },
-        { messageId: 'conditionErrorString', line: 1, column: 35 },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 9,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "return ((1 !== 0) || 'a' || null) && 0 && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output:
+                "return ((!Number.isNaN(1)) || 'a' || null) && 0 && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return ((Boolean(1)) || 'a' || null) && 0 && '' && {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 14,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output:
+                "return (1 || ('a'.length > 0) || null) && 0 && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: "return (1 || ('a' !== \"\") || null) && 0 && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return (1 || (Boolean('a')) || null) && 0 && '' && {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorNullish',
+          line: 1,
+          column: 21,
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 30,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "return (1 || 'a' || null) && (0 !== 0) && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output:
+                "return (1 || 'a' || null) && (!Number.isNaN(0)) && '' && {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return (1 || 'a' || null) && (Boolean(0)) && '' && {};",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 35,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output:
+                "return (1 || 'a' || null) && 0 && (''.length > 0) && {};",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: "return (1 || 'a' || null) && 0 && ('' !== \"\") && {};",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return (1 || 'a' || null) && 0 && (Boolean('')) && {};",
+            },
+          ],
+        },
       ],
     },
     {
@@ -567,9 +807,49 @@ if (y) {
       code: "console.log((1 && []) || ('a' && {}));",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNumber', line: 1, column: 14 },
-        { messageId: 'conditionErrorObject', line: 1, column: 19 },
-        { messageId: 'conditionErrorString', line: 1, column: 27 },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 14,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "console.log(((1 !== 0) && []) || ('a' && {}));",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output: "console.log(((!Number.isNaN(1)) && []) || ('a' && {}));",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "console.log(((Boolean(1)) && []) || ('a' && {}));",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 19,
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 27,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output: "console.log((1 && []) || (('a'.length > 0) && {}));",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: 'console.log((1 && []) || ((\'a\' !== "") && {}));',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "console.log((1 && []) || ((Boolean('a')) && {}));",
+            },
+          ],
+        },
       ],
     },
 
@@ -579,10 +859,54 @@ if (y) {
       code: "if ((1 && []) || ('a' && {})) void 0;",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNumber', line: 1, column: 6 },
-        { messageId: 'conditionErrorObject', line: 1, column: 11 },
-        { messageId: 'conditionErrorString', line: 1, column: 19 },
-        { messageId: 'conditionErrorObject', line: 1, column: 26 },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 6,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "if (((1 !== 0) && []) || ('a' && {})) void 0;",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output: "if (((!Number.isNaN(1)) && []) || ('a' && {})) void 0;",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "if (((Boolean(1)) && []) || ('a' && {})) void 0;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 11,
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 19,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output: "if ((1 && []) || (('a'.length > 0) && {})) void 0;",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: 'if ((1 && []) || ((\'a\' !== "") && {})) void 0;',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "if ((1 && []) || ((Boolean('a')) && {})) void 0;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 26,
+        },
       ],
     },
     {
@@ -590,10 +914,60 @@ if (y) {
       code: "let x = null || 0 || 'a' || [] ? {} : undefined;",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNullish', line: 1, column: 9 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 17 },
-        { messageId: 'conditionErrorString', line: 1, column: 22 },
-        { messageId: 'conditionErrorObject', line: 1, column: 29 },
+        {
+          messageId: 'conditionErrorNullish',
+          line: 1,
+          column: 9,
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 17,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output:
+                "let x = null || (0 !== 0) || 'a' || [] ? {} : undefined;",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output:
+                "let x = null || (!Number.isNaN(0)) || 'a' || [] ? {} : undefined;",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output:
+                "let x = null || (Boolean(0)) || 'a' || [] ? {} : undefined;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 22,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output:
+                "let x = null || 0 || ('a'.length > 0) || [] ? {} : undefined;",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output:
+                'let x = null || 0 || (\'a\' !== "") || [] ? {} : undefined;',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output:
+                "let x = null || 0 || (Boolean('a')) || [] ? {} : undefined;",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 29,
+        },
       ],
     },
     {
@@ -601,10 +975,54 @@ if (y) {
       code: "return !(null || 0 || 'a' || []);",
       output: null,
       errors: [
-        { messageId: 'conditionErrorNullish', line: 1, column: 10 },
-        { messageId: 'conditionErrorNumber', line: 1, column: 18 },
-        { messageId: 'conditionErrorString', line: 1, column: 23 },
-        { messageId: 'conditionErrorObject', line: 1, column: 30 },
+        {
+          messageId: 'conditionErrorNullish',
+          line: 1,
+          column: 10,
+        },
+        {
+          messageId: 'conditionErrorNumber',
+          line: 1,
+          column: 18,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareZero',
+              output: "return !(null || (0 !== 0) || 'a' || []);",
+            },
+            {
+              messageId: 'conditionFixCompareNaN',
+              output: "return !(null || (!Number.isNaN(0)) || 'a' || []);",
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return !(null || (Boolean(0)) || 'a' || []);",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorString',
+          line: 1,
+          column: 23,
+          suggestions: [
+            {
+              messageId: 'conditionFixCompareStringLength',
+              output: "return !(null || 0 || ('a'.length > 0) || []);",
+            },
+            {
+              messageId: 'conditionFixCompareEmptyString',
+              output: 'return !(null || 0 || (\'a\' !== "") || []);',
+            },
+            {
+              messageId: 'conditionFixCastBoolean',
+              output: "return !(null || 0 || (Boolean('a')) || []);",
+            },
+          ],
+        },
+        {
+          messageId: 'conditionErrorObject',
+          line: 1,
+          column: 30,
+        },
       ],
     },
 
diff --git a/packages/eslint-plugin/tests/rules/switch-exhaustiveness-check.test.ts b/packages/eslint-plugin/tests/rules/switch-exhaustiveness-check.test.ts
index ff4e2a4199db..792533c9c2b3 100644
--- a/packages/eslint-plugin/tests/rules/switch-exhaustiveness-check.test.ts
+++ b/packages/eslint-plugin/tests/rules/switch-exhaustiveness-check.test.ts
@@ -1561,6 +1561,37 @@ switch (day) {
             missingBranches:
               '"Tuesday" | "Wednesday" | "Thursday" | "Friday" | "Saturday" | "Sunday"',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+type Day =
+  | 'Monday'
+  | 'Tuesday'
+  | 'Wednesday'
+  | 'Thursday'
+  | 'Friday'
+  | 'Saturday'
+  | 'Sunday';
+
+const day = 'Monday' as Day;
+let result = 0;
+
+switch (day) {
+  case 'Monday': {
+    result = 1;
+    break;
+  }
+  case "Tuesday": { throw new Error('Not implemented yet: "Tuesday" case') }
+  case "Wednesday": { throw new Error('Not implemented yet: "Wednesday" case') }
+  case "Thursday": { throw new Error('Not implemented yet: "Thursday" case') }
+  case "Friday": { throw new Error('Not implemented yet: "Friday" case') }
+  case "Saturday": { throw new Error('Not implemented yet: "Saturday" case') }
+  case "Sunday": { throw new Error('Not implemented yet: "Sunday" case') }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1587,6 +1618,25 @@ function test(value: Enum): number {
           data: {
             missingBranches: 'Enum.B',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+enum Enum {
+  A,
+  B,
+}
+
+function test(value: Enum): number {
+  switch (value) {
+    case Enum.A:
+      return 1;
+    case Enum.B: { throw new Error('Not implemented yet: Enum.B case') }
+  }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1612,6 +1662,26 @@ function test(value: Union): number {
           data: {
             missingBranches: '"b" | "c"',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+type A = 'a';
+type B = 'b';
+type C = 'c';
+type Union = A | B | C;
+
+function test(value: Union): number {
+  switch (value) {
+    case 'a':
+      return 1;
+    case "b": { throw new Error('Not implemented yet: "b" case') }
+    case "c": { throw new Error('Not implemented yet: "c" case') }
+  }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1638,6 +1708,27 @@ function test(value: Union): number {
           data: {
             missingBranches: 'true | 1',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+const A = 'a';
+const B = 1;
+const C = true;
+
+type Union = typeof A | typeof B | typeof C;
+
+function test(value: Union): number {
+  switch (value) {
+    case 'a':
+      return 1;
+    case true: { throw new Error('Not implemented yet: true case') }
+    case 1: { throw new Error('Not implemented yet: 1 case') }
+  }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1660,6 +1751,22 @@ function test(value: DiscriminatedUnion): number {
           data: {
             missingBranches: '"B"',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+type DiscriminatedUnion = { type: 'A'; a: 1 } | { type: 'B'; b: 2 };
+
+function test(value: DiscriminatedUnion): number {
+  switch (value.type) {
+    case 'A':
+      return 1;
+    case "B": { throw new Error('Not implemented yet: "B" case') }
+  }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1689,6 +1796,33 @@ switch (day) {
             missingBranches:
               '"Monday" | "Tuesday" | "Wednesday" | "Thursday" | "Friday" | "Saturday" | "Sunday"',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+type Day =
+  | 'Monday'
+  | 'Tuesday'
+  | 'Wednesday'
+  | 'Thursday'
+  | 'Friday'
+  | 'Saturday'
+  | 'Sunday';
+
+const day = 'Monday' as Day;
+
+switch (day) {
+case "Monday": { throw new Error('Not implemented yet: "Monday" case') }
+case "Tuesday": { throw new Error('Not implemented yet: "Tuesday" case') }
+case "Wednesday": { throw new Error('Not implemented yet: "Wednesday" case') }
+case "Thursday": { throw new Error('Not implemented yet: "Thursday" case') }
+case "Friday": { throw new Error('Not implemented yet: "Friday" case') }
+case "Saturday": { throw new Error('Not implemented yet: "Saturday" case') }
+case "Sunday": { throw new Error('Not implemented yet: "Sunday" case') }
+}
+      `,
+            },
+          ],
         },
       ],
     },
@@ -1715,6 +1849,27 @@ function test(value: T): number {
           data: {
             missingBranches: 'typeof b | typeof c',
           },
+          suggestions: [
+            {
+              messageId: 'addMissingCases',
+              output: `
+const a = Symbol('a');
+const b = Symbol('b');
+const c = Symbol('c');
+
+type T = typeof a | typeof b | typeof c;
+
+function test(value: T): number {
+  switch (value) {
+    case a:
+      return 1;
+    case b: { throw new Error('Not implemented yet: b case') }
+    case c: { throw new Error('Not implemented yet: c case') }
+  }
+}
+      `,
+            },
+          ],
         },
       ],
     },
diff --git a/packages/rule-tester/src/RuleTester.ts b/packages/rule-tester/src/RuleTester.ts
index 059702547dc1..ae926072ab03 100644
--- a/packages/rule-tester/src/RuleTester.ts
+++ b/packages/rule-tester/src/RuleTester.ts
@@ -29,6 +29,7 @@ import type {
   NormalizedRunTests,
   RuleTesterConfig,
   RunTests,
+  SuggestionOutput,
   TesterConfigWithDefaults,
   ValidTestCase,
 } from './types';
@@ -40,7 +41,6 @@ import { freezeDeeply } from './utils/freezeDeeply';
 import { getRuleOptionsSchema } from './utils/getRuleOptionsSchema';
 import { hasOwnProperty } from './utils/hasOwnProperty';
 import { getPlaceholderMatcher, interpolate } from './utils/interpolate';
-import { isReadonlyArray } from './utils/isReadonlyArray';
 import { isSerializable } from './utils/serialization';
 import * as SourceCodeFixer from './utils/SourceCodeFixer';
 import {
@@ -528,7 +528,17 @@ export class RuleTester extends TestFramework {
       config = merge(config, itemConfig);
     }
 
-    if (item.filename) {
+    if (hasOwnProperty(item, 'only')) {
+      assert.ok(
+        typeof item.only === 'boolean',
+        "Optional test case property 'only' must be a boolean",
+      );
+    }
+    if (hasOwnProperty(item, 'filename')) {
+      assert.ok(
+        typeof item.filename === 'string',
+        "Optional test case property 'filename' must be a string",
+      );
       filename = item.filename;
     }
 
@@ -825,6 +835,10 @@ export class RuleTester extends TestFramework {
         if (typeof error === 'string' || error instanceof RegExp) {
           // Just an error message.
           assertMessageMatches(message.message, error);
+          assert.ok(
+            message.suggestions === undefined,
+            `Error at index ${i} has suggestions. Please convert the test error into an object and specify 'suggestions' property on it to test suggestions.`,
+          );
         } else if (typeof error === 'object' && error != null) {
           /*
            * Error object.
@@ -902,15 +916,12 @@ export class RuleTester extends TestFramework {
                 `Hydrated message "${rehydratedMessage}" does not match "${message.message}"`,
               );
             }
+          } else {
+            assert.fail(
+              "Test error must specify either a 'messageId' or 'message'.",
+            );
           }
 
-          assert.ok(
-            hasOwnProperty(error, 'data')
-              ? hasOwnProperty(error, 'messageId')
-              : true,
-            "Error must specify 'messageId' if 'data' is used.",
-          );
-
           if (error.type) {
             assert.strictEqual(
               message.nodeType,
@@ -951,149 +962,180 @@ export class RuleTester extends TestFramework {
             );
           }
 
+          assert.ok(
+            !message.suggestions || hasOwnProperty(error, 'suggestions'),
+            `Error at index ${i} has suggestions. Please specify 'suggestions' property on the test error object.`,
+          );
           if (hasOwnProperty(error, 'suggestions')) {
             // Support asserting there are no suggestions
-            if (
-              !error.suggestions ||
-              (isReadonlyArray(error.suggestions) &&
-                error.suggestions.length === 0)
-            ) {
-              if (
-                Array.isArray(message.suggestions) &&
-                message.suggestions.length > 0
-              ) {
-                assert.fail(
-                  `Error should have no suggestions on error with message: "${message.message}"`,
-                );
-              }
-            } else {
-              assert(
-                Array.isArray(message.suggestions),
-                `Error should have an array of suggestions. Instead received "${String(
-                  message.suggestions,
-                )}" on error with message: "${message.message}"`,
+            const expectsSuggestions = Array.isArray(error.suggestions)
+              ? error.suggestions.length > 0
+              : Boolean(error.suggestions);
+            const hasSuggestions = message.suggestions !== void 0;
+            // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+            const messageSuggestions = message.suggestions!;
+
+            if (!hasSuggestions && expectsSuggestions) {
+              assert.ok(
+                !error.suggestions,
+                `Error should have suggestions on error with message: "${message.message}"`,
               );
-              const messageSuggestions = message.suggestions;
-              assert.strictEqual(
-                messageSuggestions.length,
-                error.suggestions.length,
-                `Error should have ${error.suggestions.length} suggestions. Instead found ${messageSuggestions.length} suggestions`,
+            } else if (hasSuggestions) {
+              assert.ok(
+                expectsSuggestions,
+                `Error should have no suggestions on error with message: "${message.message}"`,
               );
-
-              error.suggestions.forEach((expectedSuggestion, index) => {
-                assert.ok(
-                  typeof expectedSuggestion === 'object' &&
-                    expectedSuggestion != null,
-                  "Test suggestion in 'suggestions' array must be an object.",
+              if (typeof error.suggestions === 'number') {
+                assert.strictEqual(
+                  messageSuggestions.length,
+                  error.suggestions,
+                  // It is possible that error.suggestions is a number
+                  // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+                  `Error should have ${error.suggestions} suggestions. Instead found ${messageSuggestions.length} suggestions`,
+                );
+              } else if (Array.isArray(error.suggestions)) {
+                assert.strictEqual(
+                  messageSuggestions.length,
+                  error.suggestions.length,
+                  `Error should have ${error.suggestions.length} suggestions. Instead found ${messageSuggestions.length} suggestions`,
                 );
-                Object.keys(expectedSuggestion).forEach(propertyName => {
-                  assert.ok(
-                    SUGGESTION_OBJECT_PARAMETERS.has(propertyName),
-                    `Invalid suggestion property name '${propertyName}'. Expected one of ${FRIENDLY_SUGGESTION_OBJECT_PARAMETER_LIST}.`,
-                  );
-                });
-
-                const actualSuggestion = messageSuggestions[index];
-                const suggestionPrefix = `Error Suggestion at index ${index} :`;
-
-                // @ts-expect-error -- we purposely don't define `desc` on our types as the current standard is `messageId`
-                if (hasOwnProperty(expectedSuggestion, 'desc')) {
-                  assert.ok(
-                    !hasOwnProperty(expectedSuggestion, 'data'),
-                    `${suggestionPrefix} Test should not specify both 'desc' and 'data'.`,
-                  );
-                  // @ts-expect-error -- we purposely don't define `desc` on our types as the current standard is `messageId`
-                  const expectedDesc = expectedSuggestion.desc as string;
-                  assert.strictEqual(
-                    actualSuggestion.desc,
-                    expectedDesc,
-                    `${suggestionPrefix} desc should be "${expectedDesc}" but got "${actualSuggestion.desc}" instead.`,
-                  );
-                }
-
-                if (hasOwnProperty(expectedSuggestion, 'messageId')) {
-                  assert.ok(
-                    ruleHasMetaMessages,
-                    `${suggestionPrefix} Test can not use 'messageId' if rule under test doesn't define 'meta.messages'.`,
-                  );
-                  assert.ok(
-                    hasOwnProperty(
-                      rule.meta.messages,
-                      expectedSuggestion.messageId,
-                    ),
-                    `${suggestionPrefix} Test has invalid messageId '${expectedSuggestion.messageId}', the rule under test allows only one of ${friendlyIDList}.`,
-                  );
-                  assert.strictEqual(
-                    actualSuggestion.messageId,
-                    expectedSuggestion.messageId,
-                    `${suggestionPrefix} messageId should be '${expectedSuggestion.messageId}' but got '${actualSuggestion.messageId}' instead.`,
-                  );
-
-                  const unsubstitutedPlaceholders =
-                    getUnsubstitutedMessagePlaceholders(
-                      actualSuggestion.desc,
-                      rule.meta.messages[expectedSuggestion.messageId],
-                      expectedSuggestion.data,
-                    );
 
-                  assert.ok(
-                    unsubstitutedPlaceholders.length === 0,
-                    `The message of the suggestion has ${unsubstitutedPlaceholders.length > 1 ? `unsubstituted placeholders: ${unsubstitutedPlaceholders.map(name => `'${name}'`).join(', ')}` : `an unsubstituted placeholder '${unsubstitutedPlaceholders[0]}'`}. Please provide the missing ${unsubstitutedPlaceholders.length > 1 ? 'values' : 'value'} via the 'data' property for the suggestion in the context.report() call.`,
-                  );
-
-                  if (hasOwnProperty(expectedSuggestion, 'data')) {
-                    const unformattedMetaMessage =
-                      rule.meta.messages[expectedSuggestion.messageId];
-                    const rehydratedDesc = interpolate(
-                      unformattedMetaMessage,
-                      expectedSuggestion.data,
+                error.suggestions.forEach(
+                  (expectedSuggestion: SuggestionOutput<MessageIds>, index) => {
+                    assert.ok(
+                      typeof expectedSuggestion === 'object' &&
+                        expectedSuggestion != null,
+                      "Test suggestion in 'suggestions' array must be an object.",
+                    );
+                    Object.keys(expectedSuggestion).forEach(propertyName => {
+                      assert.ok(
+                        SUGGESTION_OBJECT_PARAMETERS.has(propertyName),
+                        `Invalid suggestion property name '${propertyName}'. Expected one of ${FRIENDLY_SUGGESTION_OBJECT_PARAMETER_LIST}.`,
+                      );
+                    });
+
+                    const actualSuggestion = messageSuggestions[index];
+                    const suggestionPrefix = `Error Suggestion at index ${index}:`;
+
+                    // @ts-expect-error -- we purposely don't define `desc` on our types as the current standard is `messageId`
+                    if (hasOwnProperty(expectedSuggestion, 'desc')) {
+                      // @ts-expect-error -- we purposely don't define `desc` on our types as the current standard is `messageId`
+                      const expectedDesc = expectedSuggestion.desc as string;
+
+                      assert.ok(
+                        !hasOwnProperty(expectedSuggestion, 'data'),
+                        `${suggestionPrefix} Test should not specify both 'desc' and 'data'.`,
+                      );
+                      assert.ok(
+                        !hasOwnProperty(expectedSuggestion, 'messageId'),
+                        `${suggestionPrefix} Test should not specify both 'desc' and 'messageId'.`,
+                      );
+                      assert.strictEqual(
+                        actualSuggestion.desc,
+                        expectedDesc,
+                        `${suggestionPrefix} desc should be "${expectedDesc}" but got "${actualSuggestion.desc}" instead.`,
+                      );
+                    } else if (
+                      hasOwnProperty(expectedSuggestion, 'messageId')
+                    ) {
+                      assert.ok(
+                        ruleHasMetaMessages,
+                        `${suggestionPrefix} Test can not use 'messageId' if rule under test doesn't define 'meta.messages'.`,
+                      );
+                      assert.ok(
+                        hasOwnProperty(
+                          rule.meta.messages,
+                          expectedSuggestion.messageId,
+                        ),
+                        `${suggestionPrefix} Test has invalid messageId '${expectedSuggestion.messageId}', the rule under test allows only one of ${friendlyIDList}.`,
+                      );
+                      assert.strictEqual(
+                        actualSuggestion.messageId,
+                        expectedSuggestion.messageId,
+                        `${suggestionPrefix} messageId should be '${expectedSuggestion.messageId}' but got '${actualSuggestion.messageId}' instead.`,
+                      );
+
+                      const unsubstitutedPlaceholders =
+                        getUnsubstitutedMessagePlaceholders(
+                          actualSuggestion.desc,
+                          rule.meta.messages[expectedSuggestion.messageId],
+                          expectedSuggestion.data,
+                        );
+
+                      assert.ok(
+                        unsubstitutedPlaceholders.length === 0,
+                        `The message of the suggestion has ${unsubstitutedPlaceholders.length > 1 ? `unsubstituted placeholders: ${unsubstitutedPlaceholders.map(name => `'${name}'`).join(', ')}` : `an unsubstituted placeholder '${unsubstitutedPlaceholders[0]}'`}. Please provide the missing ${unsubstitutedPlaceholders.length > 1 ? 'values' : 'value'} via the 'data' property for the suggestion in the context.report() call.`,
+                      );
+
+                      if (hasOwnProperty(expectedSuggestion, 'data')) {
+                        const unformattedMetaMessage =
+                          rule.meta.messages[expectedSuggestion.messageId];
+                        const rehydratedDesc = interpolate(
+                          unformattedMetaMessage,
+                          expectedSuggestion.data,
+                        );
+
+                        assert.strictEqual(
+                          actualSuggestion.desc,
+                          rehydratedDesc,
+                          `${suggestionPrefix} Hydrated test desc "${rehydratedDesc}" does not match received desc "${actualSuggestion.desc}".`,
+                        );
+                      }
+                    } else if (hasOwnProperty(expectedSuggestion, 'data')) {
+                      assert.fail(
+                        `${suggestionPrefix} Test must specify 'messageId' if 'data' is used.`,
+                      );
+                    } else {
+                      assert.fail(
+                        `${suggestionPrefix} Test must specify either 'messageId' or 'desc'.`,
+                      );
+                    }
+
+                    assert.ok(
+                      hasOwnProperty(expectedSuggestion, 'output'),
+                      `${suggestionPrefix} The "output" property is required.`,
+                    );
+                    const codeWithAppliedSuggestion =
+                      SourceCodeFixer.applyFixes(item.code, [
+                        actualSuggestion,
+                      ]).output;
+
+                    // Verify if suggestion fix makes a syntax error or not.
+                    const errorMessageInSuggestion = this.#linter
+                      .verify(
+                        codeWithAppliedSuggestion,
+                        result.config,
+                        result.filename,
+                      )
+                      .find(m => m.fatal);
+
+                    assert(
+                      !errorMessageInSuggestion,
+                      [
+                        'A fatal parsing error occurred in suggestion fix.',
+                        `Error: ${errorMessageInSuggestion?.message}`,
+                        'Suggestion output:',
+                        codeWithAppliedSuggestion,
+                      ].join('\n'),
                     );
 
                     assert.strictEqual(
-                      actualSuggestion.desc,
-                      rehydratedDesc,
-                      `${suggestionPrefix} Hydrated test desc "${rehydratedDesc}" does not match received desc "${actualSuggestion.desc}".`,
-                    );
-                  }
-                } else {
-                  assert.ok(
-                    !hasOwnProperty(expectedSuggestion, 'data'),
-                    `${suggestionPrefix} Test must specify 'messageId' if 'data' is used.`,
-                  );
-                }
-
-                if (hasOwnProperty(expectedSuggestion, 'output')) {
-                  const codeWithAppliedSuggestion = SourceCodeFixer.applyFixes(
-                    item.code,
-                    [actualSuggestion],
-                  ).output;
-
-                  // Verify if suggestion fix makes a syntax error or not.
-                  const errorMessageInSuggestion = this.#linter
-                    .verify(
-                      codeWithAppliedSuggestion,
-                      result.config,
-                      result.filename,
-                    )
-                    .find(m => m.fatal);
-
-                  assert(
-                    !errorMessageInSuggestion,
-                    [
-                      'A fatal parsing error occurred in suggestion fix.',
-                      `Error: ${errorMessageInSuggestion?.message}`,
-                      'Suggestion output:',
                       codeWithAppliedSuggestion,
-                    ].join('\n'),
-                  );
-
-                  assert.strictEqual(
-                    codeWithAppliedSuggestion,
-                    expectedSuggestion.output,
-                    `Expected the applied suggestion fix to match the test suggestion output for suggestion at index: ${index} on error with message: "${message.message}"`,
-                  );
-                }
-              });
+                      expectedSuggestion.output,
+                      `Expected the applied suggestion fix to match the test suggestion output for suggestion at index: ${index} on error with message: "${message.message}"`,
+                    );
+                    assert.notStrictEqual(
+                      expectedSuggestion.output,
+                      item.code,
+                      `The output of a suggestion should differ from the original source code for suggestion at index: ${index} on error with message: "${message.message}"`,
+                    );
+                  },
+                );
+              } else {
+                assert.fail(
+                  "Test error object property 'suggestions' should be an array or a number",
+                );
+              }
             }
           }
         } else {
@@ -1123,6 +1165,11 @@ export class RuleTester extends TestFramework {
         item.code,
         "The rule fixed the code. Please add 'output' property.",
       );
+      assert.notStrictEqual(
+        item.code,
+        item.output,
+        "Test property 'output' matches 'code'. If no autofix is expected, then omit the 'output' property or set it to null.",
+      );
     }
 
     assertASTDidntChange(result.beforeAST, result.afterAST);
diff --git a/packages/rule-tester/tests/eslint-base/eslint-base.test.js b/packages/rule-tester/tests/eslint-base/eslint-base.test.js
index a50654f922aa..e87ece634534 100644
--- a/packages/rule-tester/tests/eslint-base/eslint-base.test.js
+++ b/packages/rule-tester/tests/eslint-base/eslint-base.test.js
@@ -473,7 +473,7 @@ describe("RuleTester", () => {
                     "bar = baz;"
                 ],
                 invalid: [
-                    { code: "var foo = bar; var baz = quux", errors: [{ type: "VariableDeclaration" }, null] }
+                    { code: "var foo = bar; var baz = quux", errors: [{ message: "Bad var.", type: "VariableDeclaration" }, null] }
                 ]
             });
         }, /Error should be a string, object, or RegExp/u);
@@ -529,6 +529,26 @@ describe("RuleTester", () => {
         });
     });
 
+    it("should not throw an error when the error is a string and the suggestion fixer is failing", () => {
+        ruleTester.run("no-var", require("./fixtures/suggestions").withFailingFixer, {
+            valid: [],
+            invalid: [
+                { code: "foo", errors: ["some message"] }
+            ]
+        });
+    });
+
+    it("throws an error when the error is a string and the suggestion fixer provides a fix", () => {
+        assert.throws(() => {
+            ruleTester.run("no-var", require("./fixtures/suggestions").basic, {
+                valid: [],
+                invalid: [
+                    { code: "foo", errors: ["Avoid using identifiers named 'foo'."] }
+                ]
+            });
+        }, "Error at index 0 has suggestions. Please convert the test error into an object and specify 'suggestions' property on it to test suggestions.");
+    });
+
     it("should throw an error when the error is an object with an unknown property name", () => {
         assert.throws(() => {
             ruleTester.run("no-var", require("./fixtures/no-var"), {
@@ -678,6 +698,17 @@ describe("RuleTester", () => {
         }, /Expected no autofixes to be suggested/u);
     });
 
+    it("should throw an error when the expected output is not null and the output does not differ from the code", () => {
+        assert.throws(() => {
+            ruleTester.run("no-var", require("./fixtures/no-eval"), {
+                valid: [],
+                invalid: [
+                    { code: "eval('')", output: "eval('')", errors: 1 }
+                ]
+            });
+        }, "Test property 'output' matches 'code'. If no autofix is expected, then omit the 'output' property or set it to null.");
+    });
+
     it("should throw an error when the expected output isn't specified and problems produce output", () => {
         assert.throws(() => {
             ruleTester.run("no-var", require("./fixtures/no-var"), {
@@ -913,14 +944,28 @@ describe("RuleTester", () => {
         }, /fatal parsing error/iu);
     });
 
-    it("should not throw an error if invalid code has at least an expected empty error object", () => {
-        ruleTester.run("no-eval", require("./fixtures/no-eval"), {
-            valid: ["Eval(foo)"],
-            invalid: [{
-                code: "eval(foo)",
-                errors: [{}]
-            }]
-        });
+    it("should throw an error if an error object has no properties", () => {
+        assert.throws(() => {
+            ruleTester.run("no-eval", require("./fixtures/no-eval"), {
+                valid: ["Eval(foo)"],
+                invalid: [{
+                    code: "eval(foo)",
+                    errors: [{}]
+                }]
+            });
+        }, "Test error must specify either a 'messageId' or 'message'.");
+    });
+
+    it("should throw an error if an error has a property besides message or messageId", () => {
+        assert.throws(() => {
+            ruleTester.run("no-eval", require("./fixtures/no-eval"), {
+                valid: ["Eval(foo)"],
+                invalid: [{
+                    code: "eval(foo)",
+                    errors: [{ line: 1 }]
+                }]
+            });
+        }, "Test error must specify either a 'messageId' or 'message'.");
     });
 
     it("should pass-through the globals config of valid tests to the to rule", () => {
@@ -1048,7 +1093,7 @@ describe("RuleTester", () => {
                 {
                     code: "eval(foo)",
                     parser: require.resolve("esprima"),
-                    errors: [{ line: 1 }]
+                    errors: [{ message: "eval sucks.", line: 1 }]
                 }
             ]
         });
@@ -1687,60 +1732,60 @@ describe("RuleTester", () => {
     });
 
     it("should throw if the message has a single unsubstituted placeholder when data is not specified", () => {
-      assert.throws(() => {
-        ruleTester.run("foo", require("./fixtures/messageId").withMissingData, {
-          valid: [],
-          invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
-        });
-      }, "The reported message has an unsubstituted placeholder 'name'. Please provide the missing value via the 'data' property in the context.report() call.");
+        assert.throws(() => {
+            ruleTester.run("foo", require("./fixtures/messageId").withMissingData, {
+                valid: [],
+                invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
+            });
+        }, "The reported message has an unsubstituted placeholder 'name'. Please provide the missing value via the 'data' property in the context.report() call.");
     });
 
     it("should throw if the message has a single unsubstituted placeholders when data is specified", () => {
-      assert.throws(() => {
-        ruleTester.run("foo", require("./fixtures/messageId").withMissingData, {
-          valid: [],
-          invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo", data: { name: "name" } }] }]
-        });
-      }, "Hydrated message \"Avoid using variables named 'name'.\" does not match \"Avoid using variables named '{{ name }}'.");
+        assert.throws(() => {
+            ruleTester.run("foo", require("./fixtures/messageId").withMissingData, {
+                valid: [],
+                invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo", data: { name: "name" } }] }]
+            });
+        }, "Hydrated message \"Avoid using variables named 'name'.\" does not match \"Avoid using variables named '{{ name }}'.");
     });
 
     it("should throw if the message has multiple unsubstituted placeholders when data is not specified", () => {
-      assert.throws(() => {
-        ruleTester.run("foo", require("./fixtures/messageId").withMultipleMissingDataProperties, {
-          valid: [],
-          invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
-        });
-      }, "The reported message has unsubstituted placeholders: 'type', 'name'. Please provide the missing values via the 'data' property in the context.report() call.");
+        assert.throws(() => {
+            ruleTester.run("foo", require("./fixtures/messageId").withMultipleMissingDataProperties, {
+                valid: [],
+                invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
+            });
+        }, "The reported message has unsubstituted placeholders: 'type', 'name'. Please provide the missing values via the 'data' property in the context.report() call.");
     });
 
     it("should not throw if the data in the message contains placeholders not present in the raw message", () => {
-      ruleTester.run("foo", require("./fixtures/messageId").withPlaceholdersInData, {
-        valid: [],
-        invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
-      });
+        ruleTester.run("foo", require("./fixtures/messageId").withPlaceholdersInData, {
+            valid: [],
+            invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
+        });
     });
 
     it("should throw if the data in the message contains the same placeholder and data is not specified", () => {
-      assert.throws(() => {
-        ruleTester.run("foo", require("./fixtures/messageId").withSamePlaceholdersInData, {
-          valid: [],
-          invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
-        });
-      }, "The reported message has an unsubstituted placeholder 'name'. Please provide the missing value via the 'data' property in the context.report() call.");
+        assert.throws(() => {
+            ruleTester.run("foo", require("./fixtures/messageId").withSamePlaceholdersInData, {
+                valid: [],
+                invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo" }] }]
+            });
+        }, "The reported message has an unsubstituted placeholder 'name'. Please provide the missing value via the 'data' property in the context.report() call.");
     });
 
     it("should not throw if the data in the message contains the same placeholder and data is specified", () => {
-      ruleTester.run("foo", require("./fixtures/messageId").withSamePlaceholdersInData, {
-        valid: [],
-        invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo", data: { name: "{{ name }}" } }] }]
-      });
+        ruleTester.run("foo", require("./fixtures/messageId").withSamePlaceholdersInData, {
+            valid: [],
+            invalid: [{ code: "foo", errors: [{ messageId: "avoidFoo", data: { name: "{{ name }}" } }] }]
+        });
     });
 
     it("should not throw an error for specifying non-string data values", () => {
-      ruleTester.run("foo", require("./fixtures/messageId").withNonStringData, {
-        valid: [],
-        invalid: [{ code: "0", errors: [{ messageId: "avoid", data: { value: 0 } }] }]
-      });
+        ruleTester.run("foo", require("./fixtures/messageId").withNonStringData, {
+            valid: [],
+            invalid: [{ code: "0", errors: [{ messageId: "avoid", data: { value: 0 } }] }]
+        });
     });
 
     // messageId/message misconfiguration cases
@@ -1774,10 +1819,24 @@ describe("RuleTester", () => {
                 valid: [],
                 invalid: [{ code: "foo", errors: [{ data: "something" }] }]
             });
-        }, "Error must specify 'messageId' if 'data' is used.");
+        }, "Test error must specify either a 'messageId' or 'message'.");
     });
 
     describe("suggestions", () => {
+        it("should throw if suggestions are available but not specified", () => {
+            assert.throw(() => {
+                ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
+                    valid: [
+                        "var boo;"
+                    ],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{ message: "Avoid using identifiers named 'foo'." }]
+                    }]
+                });
+            }, "Error at index 0 has suggestions. Please specify 'suggestions' property on the test error object.");
+        });
+
         it("should pass with valid suggestions (tested using desc)", () => {
             ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
                 valid: [
@@ -1786,6 +1845,7 @@ describe("RuleTester", () => {
                 invalid: [{
                     code: "var foo;",
                     errors: [{
+                        message: "Avoid using identifiers named 'foo'.",
                         suggestions: [{
                             desc: "Rename identifier 'foo' to 'bar'",
                             output: "var bar;"
@@ -1802,11 +1862,13 @@ describe("RuleTester", () => {
                     {
                         code: "function foo() {\n  var foo = 1;\n}",
                         errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [{
                                 desc: "Rename identifier 'foo' to 'bar'",
                                 output: "function bar() {\n  var foo = 1;\n}"
                             }]
                         }, {
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [{
                                 desc: "Rename identifier 'foo' to 'bar'",
                                 output: "function foo() {\n  var bar = 1;\n}"
@@ -1823,6 +1885,7 @@ describe("RuleTester", () => {
                 invalid: [{
                     code: "var foo;",
                     errors: [{
+                        message: "Avoid using identifiers named 'foo'.",
                         suggestions: [{
                             messageId: "renameFoo",
                             output: "var bar;"
@@ -1841,6 +1904,7 @@ describe("RuleTester", () => {
                 invalid: [{
                     code: "var foo;",
                     errors: [{
+                        message: "Avoid using identifiers named 'foo'.",
                         suggestions: [{
                             messageId: "renameFoo",
                             output: "var bar;"
@@ -1853,24 +1917,27 @@ describe("RuleTester", () => {
             });
         });
 
-        it("should pass with valid suggestions (tested using both desc and messageIds for the same suggestion)", () => {
-            ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
-                valid: [],
-                invalid: [{
-                    code: "var foo;",
-                    errors: [{
-                        suggestions: [{
-                            desc: "Rename identifier 'foo' to 'bar'",
-                            messageId: "renameFoo",
-                            output: "var bar;"
-                        }, {
-                            desc: "Rename identifier 'foo' to 'baz'",
-                            messageId: "renameFoo",
-                            output: "var baz;"
+        it("should fail with valid suggestions when testing using both desc and messageIds for the same suggestion", () => {
+            assert.throw(() => {
+                ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{
+                                desc: "Rename identifier 'foo' to 'bar'",
+                                messageId: "renameFoo",
+                                output: "var bar;"
+                          }, {
+                              desc: "Rename identifier 'foo' to 'baz'",
+                              messageId: "renameFoo",
+                              output: "var baz;"
+                          }]
                         }]
                     }]
-                }]
-            });
+                });
+            }, "Error Suggestion at index 0: Test should not specify both 'desc' and 'messageId'.");
         });
 
         it("should pass with valid suggestions (tested using only desc on a rule that utilizes meta.messages)", () => {
@@ -1879,6 +1946,7 @@ describe("RuleTester", () => {
                 invalid: [{
                     code: "var foo;",
                     errors: [{
+                        messageId: "avoidFoo",
                         suggestions: [{
                             desc: "Rename identifier 'foo' to 'bar'",
                             output: "var bar;"
@@ -1897,6 +1965,7 @@ describe("RuleTester", () => {
                 invalid: [{
                     code: "var foo;",
                     errors: [{
+                        messageId: "avoidFoo",
                         suggestions: [{
                             messageId: "renameFoo",
                             data: { newName: "bar" },
@@ -1912,71 +1981,89 @@ describe("RuleTester", () => {
         });
 
         it("should fail with a single missing data placeholder when data is not specified", () => {
-          assert.throws(() => {
-            ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMissingPlaceholderData, {
-              valid: [],
-              invalid: [{
-                code: "var foo;",
-                errors: [{
-                  messageId: "avoidFoo",
-                  suggestions: [{
-                    messageId: "renameFoo",
-                    output: "var bar;"
-                  }]
-                }]
-              }]
-            });
-          }, "The message of the suggestion has an unsubstituted placeholder 'newName'. Please provide the missing value via the 'data' property for the suggestion in the context.report() call.");
+            assert.throws(() => {
+                ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMissingPlaceholderData, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{
+                                messageId: "renameFoo",
+                                output: "var bar;"
+                            }]
+                        }]
+                    }]
+                });
+            }, "The message of the suggestion has an unsubstituted placeholder 'newName'. Please provide the missing value via the 'data' property for the suggestion in the context.report() call.");
         });
 
         it("should fail with a single missing data placeholder when data is specified", () => {
-          assert.throws(() => {
-            ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMissingPlaceholderData, {
-              valid: [],
-              invalid: [{
-                code: "var foo;",
-                errors: [{
-                  messageId: "avoidFoo",
-                  suggestions: [{
-                    messageId: "renameFoo",
-                    data: { other: "name" },
-                    output: "var bar;"
-                  }]
-                }]
-              }]
-            });
-          }, "The message of the suggestion has an unsubstituted placeholder 'newName'. Please provide the missing value via the 'data' property for the suggestion in the context.report() call.");
+            assert.throws(() => {
+                ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMissingPlaceholderData, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{
+                                messageId: "renameFoo",
+                                data: { other: "name" },
+                                output: "var bar;"
+                            }]
+                        }]
+                    }]
+                });
+            }, "The message of the suggestion has an unsubstituted placeholder 'newName'. Please provide the missing value via the 'data' property for the suggestion in the context.report() call.");
         });
 
         it("should fail with multiple missing data placeholders when data is not specified", () => {
-          assert.throws(() => {
-            ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMultipleMissingPlaceholderDataProperties, {
-              valid: [],
-              invalid: [{
-                code: "var foo;",
-                errors: [{
-                  messageId: "avoidFoo",
-                  suggestions: [{
-                    messageId: "rename",
-                    output: "var bar;"
-                  }]
-                }]
-              }]
-            });
-          }, "The message of the suggestion has unsubstituted placeholders: 'currentName', 'newName'. Please provide the missing values via the 'data' property for the suggestion in the context.report() call.");
+            assert.throws(() => {
+                ruleTester.run("suggestions-messageIds", require("../../fixtures/testers/rule-tester/suggestions").withMultipleMissingPlaceholderDataProperties, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{
+                                messageId: "rename",
+                                output: "var bar;"
+                            }]
+                        }]
+                    }]
+                });
+            }, "The message of the suggestion has unsubstituted placeholders: 'currentName', 'newName'. Please provide the missing values via the 'data' property for the suggestion in the context.report() call.");
         });
 
 
-        it("should pass when tested using empty suggestion test objects if the array length is correct", () => {
-            ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
-                valid: [],
-                invalid: [{
-                    code: "var foo;",
-                    errors: [{
-                        suggestions: [{}, {}]
+        it("should fail when tested using empty suggestion test objects even if the array length is correct", () => {
+            assert.throw(() => {
+                ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{}, {}]
+                        }]
                     }]
-                }]
-            });
+                });
+            }, "Error Suggestion at index 0: Test must specify either 'messageId' or 'desc'");
+        });
+
+        it("should fail when tested using non-empty suggestion test objects without an output property", () => {
+            assert.throw(() => {
+                ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            messageId: "avoidFoo",
+                            suggestions: [{ messageId: "renameFoo" }, {}]
+                        }]
+                    }]
+                });
+            }, 'Error Suggestion at index 0: The "output" property is required.');
         });
 
         it("should support explicitly expecting no suggestions", () => {
@@ -1986,6 +2073,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "eval('var foo');",
                         errors: [{
+                            message: "eval sucks.",
                             suggestions
                         }]
                     }]
@@ -2001,6 +2089,7 @@ describe("RuleTester", () => {
                         invalid: [{
                             code: "var foo;",
                             errors: [{
+                                message: "Avoid using identifiers named 'foo'.",
                                 suggestions
                             }]
                         }]
@@ -2017,12 +2106,26 @@ describe("RuleTester", () => {
                         code: "var foo;",
                         errors: [{
                             suggestions: [{
+                                message: "Bad var.",
                                 messageId: "this-does-not-exist"
                             }]
                         }]
                     }]
                 });
-            }, "Error should have an array of suggestions. Instead received \"undefined\" on error with message: \"Bad var.\"");
+            }, 'Error should have suggestions on error with message: "Bad var."');
+        });
+
+        it("should support specifying only the amount of suggestions", () => {
+            ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
+                valid: [],
+                invalid: [{
+                    code: "var foo;",
+                    errors: [{
+                        message: "Avoid using identifiers named 'foo'.",
+                        suggestions: 1
+                    }]
+                }]
+            });
         });
 
         it("should fail when there are a different number of suggestions", () => {
@@ -2032,6 +2135,22 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                          message: "Avoid using identifiers named 'foo'.",
+                          suggestions: 2
+                        }]
+                    }]
+                });
+            }, "Error should have 2 suggestions. Instead found 1 suggestions");
+        });
+
+        it("should fail when there are a different number of suggestions for arrays", () => {
+            assert.throws(() => {
+                ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [{
                                 desc: "Rename identifier 'foo' to 'bar'",
                                 output: "var bar;"
@@ -2045,6 +2164,21 @@ describe("RuleTester", () => {
             }, "Error should have 2 suggestions. Instead found 1 suggestions");
         });
 
+        it("should fail when the suggestion property is neither a number nor an array", () => {
+            assert.throws(() => {
+                ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
+                            suggestions: "1"
+                        }]
+                    }]
+                });
+            }, "Test error object property 'suggestions' should be an array or a number");
+        });
+
         it("should throw if suggestion fix made a syntax error.", () => {
             assert.throw(() => {
                 ruleTester.run(
@@ -2104,26 +2238,23 @@ describe("RuleTester", () => {
             }, "Error Suggestion at index 0 : desc should be \"not right\" but got \"Rename identifier 'foo' to 'bar'\" instead.");
         });
 
-        it("should throw if the suggestion description doesn't match (although messageIds match)", () => {
-            assert.throws(() => {
-                ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
-                    valid: [],
-                    invalid: [{
-                        code: "var foo;",
-                        errors: [{
-                            suggestions: [{
-                                desc: "Rename identifier 'foo' to 'bar'",
-                                messageId: "renameFoo",
-                                output: "var bar;"
-                            }, {
-                                desc: "Rename id 'foo' to 'baz'",
-                                messageId: "renameFoo",
-                                output: "var baz;"
-                            }]
+        it("should pass when different suggestion matchers use desc and messageId", () => {
+            ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
+                valid: [],
+                invalid: [{
+                    code: "var foo;",
+                    errors: [{
+                        messageId: "avoidFoo",
+                        suggestions: [{
+                            desc: "Rename identifier 'foo' to 'bar'",
+                            output: "var bar;"
+                        }, {
+                            messageId: "renameFoo",
+                            output: "var baz;"
                         }]
                     }]
-                });
-            }, "Error Suggestion at index 1 : desc should be \"Rename id 'foo' to 'baz'\" but got \"Rename identifier 'foo' to 'baz'\" instead.");
+                }]
+            });
         });
 
         it("should throw if the suggestion messageId doesn't match", () => {
@@ -2133,6 +2264,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 messageId: "unused",
                                 output: "var bar;"
@@ -2143,29 +2275,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 0 : messageId should be 'unused' but got 'renameFoo' instead.");
-        });
-
-        it("should throw if the suggestion messageId doesn't match (although descriptions match)", () => {
-            assert.throws(() => {
-                ruleTester.run("suggestions-messageIds", require("./fixtures/suggestions").withMessageIds, {
-                    valid: [],
-                    invalid: [{
-                        code: "var foo;",
-                        errors: [{
-                            suggestions: [{
-                                desc: "Rename identifier 'foo' to 'bar'",
-                                messageId: "renameFoo",
-                                output: "var bar;"
-                            }, {
-                                desc: "Rename identifier 'foo' to 'baz'",
-                                messageId: "avoidFoo",
-                                output: "var baz;"
-                            }]
-                        }]
-                    }]
-                });
-            }, "Error Suggestion at index 1 : messageId should be 'avoidFoo' but got 'renameFoo' instead.");
+            }, "Error Suggestion at index 0: messageId should be 'unused' but got 'renameFoo' instead.");
         });
 
         it("should throw if test specifies messageId for a rule that doesn't have meta.messages", () => {
@@ -2175,6 +2285,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [{
                                 messageId: "renameFoo",
                                 output: "var bar;"
@@ -2182,7 +2293,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 0 : Test can not use 'messageId' if rule under test doesn't define 'meta.messages'.");
+            }, "Error Suggestion at index 0: Test can not use 'messageId' if rule under test doesn't define 'meta.messages'.");
         });
 
         it("should throw if test specifies messageId that doesn't exist in the rule's meta.messages", () => {
@@ -2192,6 +2303,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 messageId: "renameFoo",
                                 output: "var bar;"
@@ -2202,7 +2314,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 1 : Test has invalid messageId 'removeFoo', the rule under test allows only one of ['avoidFoo', 'unused', 'renameFoo'].");
+            }, "Error Suggestion at index 1: Test has invalid messageId 'removeFoo', the rule under test allows only one of ['avoidFoo', 'unused', 'renameFoo'].");
         });
 
         it("should throw if hydrated desc doesn't match (wrong data value)", () => {
@@ -2212,6 +2324,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 messageId: "renameFoo",
                                 data: { newName: "car" },
@@ -2224,7 +2337,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 0 : Hydrated test desc \"Rename identifier 'foo' to 'car'\" does not match received desc \"Rename identifier 'foo' to 'bar'\".");
+            }, "Error Suggestion at index 0: Hydrated test desc \"Rename identifier 'foo' to 'car'\" does not match received desc \"Rename identifier 'foo' to 'bar'\".");
         });
 
         it("should throw if hydrated desc doesn't match (wrong data key)", () => {
@@ -2234,6 +2347,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 messageId: "renameFoo",
                                 data: { newName: "bar" },
@@ -2246,7 +2360,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 1 : Hydrated test desc \"Rename identifier 'foo' to '{{ newName }}'\" does not match received desc \"Rename identifier 'foo' to 'baz'\".");
+            }, "Error Suggestion at index 1: Hydrated test desc \"Rename identifier 'foo' to '{{ newName }}'\" does not match received desc \"Rename identifier 'foo' to 'baz'\".");
         });
 
         it("should throw if test specifies both desc and data", () => {
@@ -2256,6 +2370,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 desc: "Rename identifier 'foo' to 'bar'",
                                 messageId: "renameFoo",
@@ -2269,7 +2384,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 0 : Test should not specify both 'desc' and 'data'.");
+            }, "Error Suggestion at index 0: Test should not specify both 'desc' and 'data'.");
         });
 
         it("should throw if test uses data but doesn't specify messageId", () => {
@@ -2279,6 +2394,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            messageId: "avoidFoo",
                             suggestions: [{
                                 messageId: "renameFoo",
                                 data: { newName: "bar" },
@@ -2290,7 +2406,7 @@ describe("RuleTester", () => {
                         }]
                     }]
                 });
-            }, "Error Suggestion at index 1 : Test must specify 'messageId' if 'data' is used.");
+            }, "Error Suggestion at index 1: Test must specify 'messageId' if 'data' is used.");
         });
 
         it("should throw if the resulting suggestion output doesn't match", () => {
@@ -2300,6 +2416,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [{
                                 desc: "Rename identifier 'foo' to 'bar'",
                                 output: "var baz;"
@@ -2310,6 +2427,24 @@ describe("RuleTester", () => {
             }, "Expected the applied suggestion fix to match the test suggestion output");
         });
 
+        it("should throw if the resulting suggestion output is the same as the original source code", () => {
+            assert.throws(() => {
+                ruleTester.run("suggestions-basic", require("./fixtures/suggestions").withFixerWithoutChanges, {
+                    valid: [],
+                    invalid: [{
+                        code: "var foo;",
+                        errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
+                            suggestions: [{
+                                desc: "Rename identifier 'foo' to 'bar'",
+                                output: "var foo;"
+                            }]
+                        }]
+                    }]
+                });
+            }, "The output of a suggestion should differ from the original source code for suggestion at index: 0 on error with message: \"Avoid using identifiers named 'foo'.\"");
+        });
+
         it("should fail when specified suggestion isn't an object", () => {
             assert.throws(() => {
                 ruleTester.run("suggestions-basic", require("./fixtures/suggestions").basic, {
@@ -2317,6 +2452,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            message: "Avoid using identifiers named 'foo'.",
                             suggestions: [null]
                         }]
                     }]
@@ -2329,6 +2465,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            message: "avoidFoo",
                             suggestions: [
                                 {
                                     messageId: "renameFoo",
@@ -2351,6 +2488,7 @@ describe("RuleTester", () => {
                     invalid: [{
                         code: "var foo;",
                         errors: [{
+                            message: "avoidFoo",
                             suggestions: [{
                                 message: "Rename identifier 'foo' to 'bar'"
                             }]
@@ -2381,37 +2519,37 @@ describe("RuleTester", () => {
         });
 
         it("should fail if a rule produces two suggestions with the same description", () => {
-          assert.throws(() => {
-              ruleTester.run("suggestions-with-duplicate-descriptions", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateDescriptions, {
-                  valid: [],
-                  invalid: [
-                      { code: "var foo = bar;", errors: 1 }
-                  ]
-              });
-          }, "Suggestion message 'Rename 'foo' to 'bar'' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
-      });
-
-      it("should fail if a rule produces two suggestions with the same messageId without data", () => {
-          assert.throws(() => {
-              ruleTester.run("suggestions-with-duplicate-messageids-no-data", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateMessageIdsNoData, {
-                  valid: [],
-                  invalid: [
-                      { code: "var foo = bar;", errors: 1 }
-                  ]
-              });
-          }, "Suggestion message 'Rename identifier' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
-      });
-
-      it("should fail if a rule produces two suggestions with the same messageId with data", () => {
-          assert.throws(() => {
-              ruleTester.run("suggestions-with-duplicate-messageids-with-data", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateMessageIdsWithData, {
-                  valid: [],
-                  invalid: [
-                      { code: "var foo = bar;", errors: 1 }
-                  ]
-              });
-          }, "Suggestion message 'Rename identifier 'foo' to 'bar'' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
-      });
+            assert.throws(() => {
+                ruleTester.run("suggestions-with-duplicate-descriptions", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateDescriptions, {
+                    valid: [],
+                    invalid: [
+                        { code: "var foo = bar;", errors: 1 }
+                    ]
+                });
+            }, "Suggestion message 'Rename 'foo' to 'bar'' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
+        });
+
+        it("should fail if a rule produces two suggestions with the same messageId without data", () => {
+            assert.throws(() => {
+                ruleTester.run("suggestions-with-duplicate-messageids-no-data", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateMessageIdsNoData, {
+                    valid: [],
+                    invalid: [
+                        { code: "var foo = bar;", errors: 1 }
+                    ]
+                });
+            }, "Suggestion message 'Rename identifier' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
+        });
+
+        it("should fail if a rule produces two suggestions with the same messageId with data", () => {
+            assert.throws(() => {
+                ruleTester.run("suggestions-with-duplicate-messageids-with-data", require("../../fixtures/testers/rule-tester/suggestions").withDuplicateMessageIdsWithData, {
+                    valid: [],
+                    invalid: [
+                        { code: "var foo = bar;", errors: 1 }
+                    ]
+                });
+            }, "Suggestion message 'Rename identifier 'foo' to 'bar'' reported from suggestion 1 was previously reported by suggestion 0. Suggestion messages should be unique within an error.");
+        });
 
         it("should throw an error if a rule that doesn't have `meta.hasSuggestions` enabled produces suggestions", () => {
             assert.throws(() => {
@@ -2922,6 +3060,43 @@ describe("RuleTester", () => {
         }, /A fatal parsing error occurred in autofix.\nError: .+\nAutofix output:\n.+/u);
     });
 
+    describe("type checking", () => {
+        it('should throw if "only" property is not a boolean', () => {
+
+            // "only" has to be falsy as itOnly is not mocked for all test cases
+            assert.throws(() => {
+                ruleTester.run("foo", require("./fixtures/no-var"), {
+                    valid: [{ code: "foo", only: "" }],
+                    invalid: []
+                });
+            }, /Optional test case property 'only' must be a boolean/u);
+
+            assert.throws(() => {
+                ruleTester.run("foo", require("./fixtures/no-var"), {
+                    valid: [],
+                    invalid: [{ code: "foo", only: 0, errors: 1 }]
+                });
+            }, /Optional test case property 'only' must be a boolean/u);
+        });
+
+        it('should throw if "filename" property is not a string', () => {
+            assert.throws(() => {
+                ruleTester.run("foo", require("./fixtures/no-var"), {
+                    valid: [{ code: "foo", filename: false }],
+                    invalid: []
+
+                });
+            }, /Optional test case property 'filename' must be a string/u);
+
+            assert.throws(() => {
+                ruleTester.run("foo", require("./fixtures/no-var"), {
+                    valid: ["foo"],
+                    invalid: [{ code: "foo", errors: 1, filename: 0 }]
+                });
+            }, /Optional test case property 'filename' must be a string/u);
+        });
+    });
+
     describe("sanitize test cases", () => {
         let originalRuleTesterIt;
         let spyRuleTesterIt;
diff --git a/packages/rule-tester/tests/eslint-base/fixtures/suggestions.js b/packages/rule-tester/tests/eslint-base/fixtures/suggestions.js
index 71781086f4b8..6310d0a2104a 100644
--- a/packages/rule-tester/tests/eslint-base/fixtures/suggestions.js
+++ b/packages/rule-tester/tests/eslint-base/fixtures/suggestions.js
@@ -167,6 +167,40 @@ module.exports.withoutHasSuggestionsProperty = {
     }
 };
 
+module.exports.withFixerWithoutChanges = {
+  meta: { hasSuggestions: true },
+  create(context) {
+    return {
+      Identifier(node) {
+        if (node.name === "foo") {
+          context.report({
+            node,
+            message: "Avoid using identifiers named 'foo'.",
+            suggest: [{
+              desc: "Rename identifier 'foo' to 'bar'",
+              fix: fixer => fixer.replaceText(node, 'foo')
+            }]
+          });
+        }
+      }
+    };
+  }
+};
+
+module.exports.withFailingFixer = {
+  create(context) {
+    return {
+      Identifier(node) {
+        context.report({
+          node,
+          message: "some message",
+          suggest: [{ desc: "some suggestion", fix: fixer => null }]
+        });
+      }
+    };
+  }
+};
+
 module.exports.withMissingPlaceholderData = {
   meta: {
     messages: {

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