feat: Add language to types (#18917)

nzakas · web-flow · commit c591da68d4a9 · 2024-09-18T08:59:24.000+02:00
diff --git a/lib/types/index.d.ts b/lib/types/index.d.ts
@@ -26,6 +26,7 @@
  */
 
 import * as ESTree from "estree";
+import { Language } from "@eslint/core";
 import { JSONSchema4 } from "json-schema";
 import { LegacyESLint } from "./use-at-your-own-risk.js";
 
@@ -1265,6 +1266,13 @@ export namespace Linter {
          */
         ignores?: string[];
 
+        /**
+         * The name of the language used for linting. This is used to determine the
+         * parser and other language-specific settings.
+         * @since 9.7.0
+         */
+        language?: string;
+
         /**
          * An object containing settings related to how JavaScript is configured for
          * linting.
@@ -1441,6 +1449,7 @@ export namespace ESLint {
     interface Plugin extends ObjectMetaProperties {
         configs?: Record<string, Linter.LegacyConfig | Linter.Config | Linter.Config[]> | undefined;
         environments?: Record<string, Environment> | undefined;
+        languages?: Record<string, Language> | undefined;
         processors?: Record<string, Linter.Processor> | undefined;
         rules?: Record<string, Rule.RuleModule> | undefined;
     }
diff --git a/tests/lib/types/types.test.ts b/tests/lib/types/types.test.ts
@@ -35,6 +35,7 @@ import {
     shouldUseFlatConfig,
 } from "eslint/use-at-your-own-risk";
 import { Comment, PrivateIdentifier, PropertyDefinition, StaticBlock, WhileStatement } from "estree";
+import { Language } from "@eslint/core";
 
 const SOURCE = `var foo = bar;`;
 
@@ -1354,6 +1355,15 @@ ruleTester.run("simple-valid-test", rule, {
 
 // #region Config
 
+((): Linter.Config => ({
+    language: "js/js"
+}));
+
+((): Linter.Config => ({
+    // @ts-expect-error
+    language: null
+}));
+
 ((): Linter.Config => ({
     languageOptions: {
         parser: {
@@ -1496,6 +1506,16 @@ flatConfig = config;
 
 // #endregion Config
 
+// #region Plugins
+
+((): ESLint.Plugin => ({
+    languages: {
+        "js": {} as Language
+    }
+}));
+
+// #endregion Plugins
+
 (async (useFlatConfig?: boolean) => {
     await loadESLint(); // $ExpectType typeof ESLint | typeof LegacyESLint
     await loadESLint({}); // $ExpectType typeof ESLint | typeof LegacyESLint
