typescript-eslint · auvred · Feb 3, 2024 · Feb 3, 2024 · Feb 3, 2024 · Sep 21, 2024
diff --git a/.cspell.json b/.cspell.json
@@ -135,6 +135,7 @@
     "necroing",
     "Nicolò",
     "nocheck",
+    "nodenext",
     "noninteractive",
     "Nrwl",
     "nullish",

diff --git a/packages/eslint-plugin/tests/fixtures/tsconfig.json b/packages/eslint-plugin/tests/fixtures/tsconfig.json
@@ -1,12 +1,14 @@
 {
   "compilerOptions": {
     "jsx": "preserve",
-    "target": "es5",
+    "target": "es2020",
     "module": "commonjs",
     "strict": true,
     "esModuleInterop": true,
     "lib": ["es2015", "es2017", "esnext"],
-    "experimentalDecorators": true
+    "types": [],
+    "experimentalDecorators": true,
+    "skipLibCheck": true
   },
   "include": [
     "file.ts",

diff --git a/packages/rule-tester/package.json b/packages/rule-tester/package.json
@@ -72,6 +72,11 @@
     "source-map-support": "^0.5.21",
     "typescript": "*"
   },
+  "peerDependenciesMeta": {
+    "typescript": {
+      "optional": true
+    }
+  },
   "funding": {
     "type": "opencollective",
     "url": "https://opencollective.com/typescript-eslint"

diff --git a/packages/rule-tester/src/RuleTester.ts b/packages/rule-tester/src/RuleTester.ts
@@ -7,16 +7,21 @@ import type {
   AnyRuleCreateFunction,
   AnyRuleModule,
   ParserOptions,
+  RuleContext,
   RuleListener,
   RuleModule,
 } from '@typescript-eslint/utils/ts-eslint';
 
 import * as parser from '@typescript-eslint/parser';
-import { deepMerge } from '@typescript-eslint/utils/eslint-utils';
+import {
+  deepMerge,
+  getParserServices,
+} from '@typescript-eslint/utils/eslint-utils';
 import { Linter } from '@typescript-eslint/utils/ts-eslint';
 import assert from 'node:assert';
 import path from 'node:path';
 import util from 'node:util';
+import * as ts from 'typescript';
 // we intentionally import from eslint here because we need to use the same class
 // that ESLint uses, not our custom override typed version
 import { SourceCode } from 'eslint';
@@ -181,7 +186,10 @@ export class RuleTester extends TestFramework {
      * configuration and the default configuration.
      */
     this.#testerConfig = merge({}, defaultConfig, testerConfig, {
-      rules: { [`${RULE_TESTER_PLUGIN_PREFIX}validate-ast`]: 'error' },
+      rules: {
+        [`${RULE_TESTER_PLUGIN_PREFIX}collect-ts-diagnostics`]: 'error',
+        [`${RULE_TESTER_PLUGIN_PREFIX}validate-ast`]: 'error',
+      },
     });
 
     this.#lintersByBasePath = new Map();
@@ -629,11 +637,37 @@ export class RuleTester extends TestFramework {
   } {
     this.defineRule(ruleName, rule);
 
+    const shouldCollectTSDiagnostics =
+      item.runTSC === true ||
+      (item.runTSC !== false &&
+        rule.meta.docs &&
+        'requiresTypeChecking' in rule.meta.docs &&
+        !!rule.meta.docs.requiresTypeChecking);
+    let tsDiagnostics = null as readonly ts.Diagnostic[] | null;
     let config: TesterConfigWithDefaults = merge({}, this.#testerConfig, {
       files: ['**'],
       plugins: {
         [RULE_TESTER_PLUGIN]: {
           rules: {
+            'collect-ts-diagnostics': {
+              create(
+                context: Readonly<RuleContext<string, unknown[]>>,
+              ): RuleListener {
+                if (!shouldCollectTSDiagnostics) {
+                  return {};
+                }
+                const services = getParserServices(context);
+                return {
+                  Program(): void {
+                    const diagnostics =
+                      services.program.getSemanticDiagnostics();
+                    if (diagnostics.length) {
+                      tsDiagnostics ??= diagnostics;
+                    }
+                  },
+                };
+              },
+            },
             /**
              * Setup AST getters.
              * The goal is to check whether or not AST was modified when
@@ -655,7 +689,7 @@ export class RuleTester extends TestFramework {
           },
         },
       },
-    });
+    } satisfies RuleTesterConfig);
 
     // Unlike other properties, we don't want to spread props between different parsers.
     config.languageOptions.parser =
@@ -836,6 +870,29 @@ export class RuleTester extends TestFramework {
         ].join('\n'),
       );
     } while (fixedResult.fixed && passNumber < 10);
+    if (tsDiagnostics) {
+      const codesToIgnore = [
+        1375 /* 'await' expressions are only allowed at the top level of a file when that file is a module, but this file has no imports or exports. Consider adding an empty 'export {}' to make this file a module. */,
+        1378 /* Top-level 'await' expressions are only allowed when the 'module' option is set to 'es2022', 'esnext', 'system', 'node16', 'nodenext', or 'preserve', and the 'target' option is set to 'es2017' or higher. */,
+        6133 /* '{0}' is declared but its value is never read. */,
+        6138 /* Property '{0}' is declared but its value is never read. */,
+      ];
+      for (const diagnostic of tsDiagnostics) {
+        if (
+          diagnostic.category !== ts.DiagnosticCategory.Error ||
+          codesToIgnore.includes(diagnostic.code)
+        ) {
+          continue;
+        }
+
+        throw new Error(
+          `error TS${diagnostic.code}: ${ts.flattenDiagnosticMessageText(
+            diagnostic.messageText,
+            ts.sys.newLine,
+          )}`,
+        );
+      }
+    }
 
     return {
       config,

diff --git a/packages/rule-tester/src/types/ValidTestCase.ts b/packages/rule-tester/src/types/ValidTestCase.ts
@@ -63,6 +63,10 @@ export interface ValidTestCase<Options extends readonly unknown[]> {
    * Options for the test case.
    */
   readonly options?: Readonly<Options>;
+  /**
+   * TODO: add description (or maybe even give a better name?)
+   */
+  readonly runTSC?: boolean;
   /**
    * Settings for the test case.
    */

diff --git a/packages/rule-tester/src/utils/validationHelpers.ts b/packages/rule-tester/src/utils/validationHelpers.ts
@@ -20,6 +20,7 @@ export const RULE_TESTER_PARAMETERS = [
   'options',
   'output',
   'skip',
+  'runTSC',
 ] as const;
 
 /*