typescript-eslint · nayounsang · Jun 5, 2025 · Jun 5, 2025 · Jun 5, 2025 · Jun 5, 2025
diff --git a/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/gatherLogicalOperands.ts b/packages/eslint-plugin/src/rules/prefer-optional-chain-utils/gatherLogicalOperands.ts
@@ -248,12 +248,13 @@ export function gatherLogicalOperands(
       case AST_NODE_TYPES.UnaryExpression:
         if (
           operand.operator === '!' &&
-          isValidFalseBooleanCheckType(
-            operand.argument,
-            areMoreOperands && node.operator === '||',
-            parserServices,
-            options,
-          )
+          (!areMoreOperands ||
+            isValidFalseBooleanCheckType(
+              operand.argument,
+              node.operator === '||',
+              parserServices,
+              options,
+            ))
         ) {
           result.push({
             comparedName: operand.argument,
@@ -274,9 +275,10 @@ export function gatherLogicalOperands(
 
       default:
         if (
+          !areMoreOperands ||
           isValidFalseBooleanCheckType(
             operand,
-            areMoreOperands && node.operator === '&&',
+            node.operator === '&&',
             parserServices,
             options,
           )

diff --git a/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts b/packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts
@@ -1680,6 +1680,46 @@ describe('hand-crafted cases', () => {
         ],
         output: 'a?.prop;',
       },
+      {
+        code: `
+declare const foo: {
+  bar: undefined | (() => void);
+};
+
+foo.bar && foo.bar();
+        `,
+        errors: [{ messageId: 'preferOptionalChain' }],
+        output: `
+declare const foo: {
+  bar: undefined | (() => void);
+};
+
+foo.bar?.();
+        `,
+      },
+      {
+        code: `
+declare const foo: { bar: string };
+
+const baz = foo && foo.bar;
+        `,
+        errors: [
+          {
+            messageId: 'preferOptionalChain',
+            suggestions: [
+              {
+                messageId: 'optionalChainSuggest',
+                output: `
+declare const foo: { bar: string };
+
+const baz = foo?.bar;
+        `,
+              },
+            ],
+          },
+        ],
+        options: [{ checkString: false }],
+      },
     ],
     valid: [
       '!a || !b;',
@@ -1917,6 +1957,10 @@ describe('hand-crafted cases', () => {
         !x || x.a;
       `,
       "typeof globalThis !== 'undefined' && globalThis.Array();",
+      `
+        declare const x: void;
+        x && x();
+      `,
     ],
   });
 });