typescript-eslint · nayounsang · Jun 20, 2025 · Jun 20, 2025 · Jun 20, 2025 · Jun 20, 2025
diff --git a/eslint-suppressions.json b/eslint-suppressions.json
@@ -0,0 +1,97 @@
+{
+  "packages/eslint-plugin-internal/tests/rules/plugin-test-formatting.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 26
+    }
+  },
+  "packages/eslint-plugin/tests/rules/dot-notation.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 1
+    }
+  },
+  "packages/eslint-plugin/tests/rules/member-ordering/member-ordering-alphabetically-case-insensitive-order.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 4
+    }
+  },
+  "packages/eslint-plugin/tests/rules/member-ordering/member-ordering-alphabetically-order.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 4
+    }
+  },
+  "packages/eslint-plugin/tests/rules/naming-convention/naming-convention.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 12
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-extraneous-class.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 12
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-invalid-this.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 43
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-loop-func.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 2
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-this-alias.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 14
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-unnecessary-condition.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 44
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-unnecessary-template-expression.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 1
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-unsafe-enum-comparison.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 2
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars-eslint.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 154
+    }
+  },
+  "packages/eslint-plugin/tests/rules/no-useless-empty-export.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 9
+    }
+  },
+  "packages/eslint-plugin/tests/rules/prefer-nullish-coalescing.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 42
+    }
+  },
+  "packages/eslint-plugin/tests/rules/prefer-optional-chain/prefer-optional-chain.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 17
+    }
+  },
+  "packages/eslint-plugin/tests/rules/return-await.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 1
+    }
+  },
+  "packages/eslint-plugin/tests/rules/sort-type-constituents.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 4
+    }
+  },
+  "packages/eslint-plugin/tests/rules/unbound-method.test.ts": {
+    "@typescript-eslint/internal/no-dynamic-tests": {
+      "count": 3
+    }
+  }
+}
diff --git a/eslint.config.mjs b/eslint.config.mjs
@@ -416,6 +416,7 @@ export default tseslint.config(
     ],
     name: 'eslint-plugin-and-eslint-plugin-internal/test-files/rules',
     rules: {
+      '@typescript-eslint/internal/no-dynamic-tests': 'error',
       '@typescript-eslint/internal/plugin-test-formatting': 'error',
     },
   },

diff --git a/package.json b/package.json
@@ -37,6 +37,7 @@
     "lint-markdown-fix": "yarn lint-markdown --fix",
     "lint-markdown": "markdownlint \"**/*.md\" --config=.markdownlint.json --ignore-path=.markdownlintignore",
     "lint-stylelint": "nx lint website stylelint",
+    "lint-prune-suppressions": "nx run-many -t lint --projects=eslint-plugin-internal,eslint-plugin --prune-suppressions",
     "lint": "nx run-many -t lint",
     "postinstall": "tsx tools/scripts/postinstall.mts",
     "pre-commit": "lint-staged",
@@ -77,7 +78,7 @@
     "console-fail-test": "^0.5.0",
     "cross-fetch": "^4.0.0",
     "cspell": "^9.0.0",
-    "eslint": "^9.26.0",
+    "eslint": "^9.30.1",
     "eslint-plugin-eslint-plugin": "^6.3.1",
     "eslint-plugin-import": "^2.31.0",
     "eslint-plugin-jsdoc": "^50.5.0",

diff --git a/packages/eslint-plugin-internal/src/rules/index.ts b/packages/eslint-plugin-internal/src/rules/index.ts
@@ -2,6 +2,7 @@ import type { Linter } from '@typescript-eslint/utils/ts-eslint';
 
 import debugNamespace from './debug-namespace';
 import eqeqNullish from './eqeq-nullish';
+import noDynamicTests from './no-dynamic-tests';
 import noPoorlyTypedTsProps from './no-poorly-typed-ts-props';
 import noRelativePathsToInternalPackages from './no-relative-paths-to-internal-packages';
 import noTypescriptDefaultImport from './no-typescript-default-import';
@@ -12,6 +13,7 @@ import preferASTTypesEnum from './prefer-ast-types-enum';
 export default {
   'debug-namespace': debugNamespace,
   'eqeq-nullish': eqeqNullish,
+  'no-dynamic-tests': noDynamicTests,
   'no-poorly-typed-ts-props': noPoorlyTypedTsProps,
   'no-relative-paths-to-internal-packages': noRelativePathsToInternalPackages,
   'no-typescript-default-import': noTypescriptDefaultImport,

diff --git a/packages/eslint-plugin-internal/src/rules/no-dynamic-tests.ts b/packages/eslint-plugin-internal/src/rules/no-dynamic-tests.ts
@@ -0,0 +1,140 @@
+import type { InvalidTestCase } from '@typescript-eslint/rule-tester';
+import type { TSESTree } from '@typescript-eslint/utils';
+
+import { AST_NODE_TYPES } from '@typescript-eslint/utils';
+
+import { createRule } from '../util';
+
+export default createRule({
+  name: 'no-dynamic-tests',
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'Disallow dynamic syntax in RuleTester test arrays',
+    },
+    messages: {
+      noDynamicTests:
+        'Dynamic syntax is not allowed in RuleTester test arrays. Use static values only.',
+    },
+    schema: [],
+  },
+  defaultOptions: [],
+  create(context) {
+    function isRuleTesterCall(node: TSESTree.Node): boolean {
+      return (
+        node.type === AST_NODE_TYPES.CallExpression &&
+        node.callee.type === AST_NODE_TYPES.MemberExpression &&
+        node.callee.object.type === AST_NODE_TYPES.Identifier &&
+        node.callee.object.name === 'ruleTester' &&
+        node.callee.property.type === AST_NODE_TYPES.Identifier &&
+        node.callee.property.name === 'run'
+      );
+    }
+
+    function reportDynamicElements(node: TSESTree.Node): void {
+      switch (node.type) {
+        case AST_NODE_TYPES.CallExpression:
+        case AST_NODE_TYPES.SpreadElement:
+        case AST_NODE_TYPES.Identifier:
+        case AST_NODE_TYPES.BinaryExpression:
+        case AST_NODE_TYPES.ConditionalExpression:
+        case AST_NODE_TYPES.MemberExpression:
+          context.report({
+            node,
+            messageId: 'noDynamicTests',
+          });
+          break;
+        case AST_NODE_TYPES.TemplateLiteral:
+          node.expressions.forEach(expr => {
+            reportDynamicElements(expr);
+          });
+          break;
+        case AST_NODE_TYPES.ArrayExpression:
+          node.elements.forEach(element => {
+            if (element) {
+              reportDynamicElements(element);
+            }
+          });
+          break;
+        case AST_NODE_TYPES.ObjectExpression:
+          node.properties.forEach(prop => {
+            if (prop.type === AST_NODE_TYPES.SpreadElement) {
+              context.report({
+                node: prop,
+                messageId: 'noDynamicTests',
+              });
+            } else {
+              // InvalidTestCase extends ValidTestCase
+              type TestCaseKey = keyof InvalidTestCase<string, []>;
+              const keyToValidate: TestCaseKey[] = ['code', 'errors'];
+
+              if (
+                prop.key.type === AST_NODE_TYPES.Identifier &&
+                keyToValidate.includes(prop.key.name as TestCaseKey)
+              ) {
+                reportDynamicElements(prop.value);
+              } else if (
+                prop.key.type === AST_NODE_TYPES.Literal &&
+                keyToValidate.includes(prop.key.value as TestCaseKey)
+              ) {
+                reportDynamicElements(prop.value);
+              }
+            }
+          });
+          break;
+        case AST_NODE_TYPES.TaggedTemplateExpression:
+          if (
+            !(
+              node.tag.type === AST_NODE_TYPES.Identifier &&
+              node.tag.name === 'noFormat'
+            )
+          ) {
+            context.report({
+              node: node.tag,
+              messageId: 'noDynamicTests',
+            });
+          }
+          break;
+        case AST_NODE_TYPES.Literal:
+        default:
+          break;
+      }
+    }
+
+    return {
+      CallExpression(node) {
+        if (isRuleTesterCall(node)) {
+          // If valid code, arg length is always 3 but we need to avoid conflict while dev
+          if (node.arguments.length < 3) {
+            return;
+          }
+          const testObject = node.arguments[2];
+
+          if (testObject.type === AST_NODE_TYPES.ObjectExpression) {
+            for (const prop of testObject.properties) {
+              const isTestCases =
+                prop.type === AST_NODE_TYPES.Property &&
+                prop.key.type === AST_NODE_TYPES.Identifier &&
+                (prop.key.name === 'valid' || prop.key.name === 'invalid');
+
+              if (isTestCases) {
+                if (prop.value.type === AST_NODE_TYPES.ArrayExpression) {
+                  prop.value.elements.forEach(element => {
+                    if (element) {
+                      reportDynamicElements(element);
+                    }
+                  });
+                } else {
+                  context.report({
+                    node: prop.value,
+                    messageId: 'noDynamicTests',
+                  });
+                }
+              }
+            }
+          }
+        }
+      },
+    };
+  },
+});