feat: unflag TypeScript config files (#19266)

fasttime · web-flow · commit 8efc2d0c92da · 2024-12-27T15:06:15.000+08:00
diff --git a/docs/src/use/configure/configuration-files.md b/docs/src/use/configure/configuration-files.md
@@ -517,18 +517,6 @@ For more information about using feature flags, see [Feature Flags](../../flags/
 
 ## TypeScript Configuration Files
 
-::: warning
-This feature is currently experimental and may change in future versions.
-:::
-
-You need to enable this feature through the `unstable_ts_config` feature flag:
-
-```bash
-npx eslint --flag unstable_ts_config
-```
-
-For more information about using feature flags, see [Feature Flags](../../flags/).
-
 For Deno and Bun, TypeScript configuration files are natively supported; for Node.js, you must install the optional dev dependency [`jiti`](https://github.com/unjs/jiti) in version 2.0.0 or later in your project (this dependency is not automatically installed by ESLint):
 
 ```bash
@@ -591,5 +579,5 @@ If you have multiple ESLint configuration files, ESLint prioritizes JavaScript f
 To override this behavior, use the `--config` or `-c` command line option to specify a different configuration file:
 
 ```bash
-npx eslint --flag unstable_ts_config --config eslint.config.ts
+npx eslint --config eslint.config.ts
 ```
diff --git a/lib/cli.js b/lib/cli.js
@@ -341,16 +341,15 @@ const cli = {
     /**
      * Calculates the command string for the --inspect-config operation.
      * @param {string} configFile The path to the config file to inspect.
-     * @param {boolean} hasUnstableTSConfigFlag `true` if the `unstable_ts_config` flag is enabled, `false` if it's not.
      * @returns {Promise<string>} The command string to execute.
      */
-    async calculateInspectConfigFlags(configFile, hasUnstableTSConfigFlag) {
+    async calculateInspectConfigFlags(configFile) {
 
         // find the config file
         const {
             configFilePath,
             basePath
-        } = await locateConfigFileToUse({ cwd: process.cwd(), configFile }, hasUnstableTSConfigFlag);
+        } = await locateConfigFileToUse({ cwd: process.cwd(), configFile });
 
         return ["--config", configFilePath, "--basePath", basePath];
     },
@@ -451,7 +450,7 @@ const cli = {
             try {
                 const flatOptions = await translateOptions(options, "flat");
                 const spawn = require("cross-spawn");
-                const flags = await cli.calculateInspectConfigFlags(flatOptions.overrideConfigFile, flatOptions.flags ? flatOptions.flags.includes("unstable_ts_config") : false);
+                const flags = await cli.calculateInspectConfigFlags(flatOptions.overrideConfigFile);
 
                 spawn.sync("npx", ["@eslint/config-inspector@latest", ...flags], { encoding: "utf8", stdio: "inherit" });
             } catch (error) {
diff --git a/lib/config/config-loader.js b/lib/config/config-loader.js
@@ -31,7 +31,6 @@ const { FlatConfigArray } = require("./flat-config-array");
  * @property {Array<FlatConfigObject>} [defaultConfigs] The default configs to use.
  * @property {Array<string>} [ignorePatterns] The ignore patterns to use.
  * @property {FlatConfigObject|Array<FlatConfigObject>} overrideConfig The override config to use.
- * @property {boolean} allowTS Indicates if TypeScript configuration files are allowed.
  */
 
 //------------------------------------------------------------------------------
@@ -41,10 +40,7 @@ const { FlatConfigArray } = require("./flat-config-array");
 const FLAT_CONFIG_FILENAMES = [
     "eslint.config.js",
     "eslint.config.mjs",
-    "eslint.config.cjs"
-];
-
-const TS_FLAT_CONFIG_FILENAMES = [
+    "eslint.config.cjs",
     "eslint.config.ts",
     "eslint.config.mts",
     "eslint.config.cts"
@@ -119,10 +115,9 @@ function isRunningInDeno() {
 /**
  * Load the config array from the given filename.
  * @param {string} filePath The filename to load from.
- * @param {boolean} allowTS Indicates if TypeScript configuration files are allowed.
  * @returns {Promise<any>} The config loaded from the config file.
  */
-async function loadConfigFile(filePath, allowTS) {
+async function loadConfigFile(filePath) {
 
     debug(`Loading config from ${filePath}`);
 
@@ -171,7 +166,7 @@ async function loadConfigFile(filePath, allowTS) {
      *
      * When Node.js supports native TypeScript imports, we can remove this check.
      */
-    if (allowTS && isTS && !isDeno && !isBun) {
+    if (isTS && !isDeno && !isBun) {
 
         // eslint-disable-next-line no-use-before-define -- `ConfigLoader.loadJiti` can be overwritten for testing
         const { createJiti } = await ConfigLoader.loadJiti().catch(() => {
@@ -261,8 +256,7 @@ class ConfigLoader {
         const resultPromise = ConfigLoader.locateConfigFileToUse({
             useConfigFile: this.#options.configFile,
             cwd: this.#options.cwd,
-            fromDirectory,
-            allowTS: this.#options.allowTS
+            fromDirectory
         });
 
         // ensure `ConfigLoader.locateConfigFileToUse` is called only once for `fromDirectory`
@@ -443,15 +437,10 @@ class ConfigLoader {
      * @param {string|false|undefined} options.useConfigFile The path to the config file to use.
      * @param {string} options.cwd Path to a directory that should be considered as the current working directory.
      * @param {string} [options.fromDirectory] The directory from which to start searching. Defaults to `cwd`.
-     * @param {boolean} options.allowTS Indicates if TypeScript configuration files are allowed.
      * @returns {Promise<{configFilePath:string|undefined,basePath:string}>} Location information for
      *      the config file.
      */
-    static async locateConfigFileToUse({ useConfigFile, cwd, fromDirectory = cwd, allowTS }) {
-
-        const configFilenames = allowTS
-            ? [...FLAT_CONFIG_FILENAMES, ...TS_FLAT_CONFIG_FILENAMES]
-            : FLAT_CONFIG_FILENAMES;
+    static async locateConfigFileToUse({ useConfigFile, cwd, fromDirectory = cwd }) {
 
         // determine where to load config file from
         let configFilePath;
@@ -464,7 +453,7 @@ class ConfigLoader {
         } else if (useConfigFile !== false) {
             debug("Searching for eslint.config.js");
             configFilePath = await findUp(
-                configFilenames,
+                FLAT_CONFIG_FILENAMES,
                 { cwd: fromDirectory }
             );
 
@@ -497,8 +486,7 @@ class ConfigLoader {
             ignoreEnabled,
             ignorePatterns,
             overrideConfig,
-            defaultConfigs = [],
-            allowTS
+            defaultConfigs = []
         } = options;
 
         debug(`Calculating config array from config file ${configFilePath} and base path ${basePath}`);
@@ -509,7 +497,7 @@ class ConfigLoader {
         if (configFilePath) {
 
             debug(`Loading config file ${configFilePath}`);
-            const fileConfig = await loadConfigFile(configFilePath, allowTS);
+            const fileConfig = await loadConfigFile(configFilePath);
 
             if (Array.isArray(fileConfig)) {
                 configs.push(...fileConfig);
@@ -618,8 +606,7 @@ class LegacyConfigLoader extends ConfigLoader {
         if (!this.#configFilePath) {
             this.#configFilePath = ConfigLoader.locateConfigFileToUse({
                 useConfigFile: this.#options.configFile,
-                cwd: this.#options.cwd,
-                allowTS: this.#options.allowTS
+                cwd: this.#options.cwd
             });
         }
 
diff --git a/lib/eslint/eslint.js b/lib/eslint/eslint.js
@@ -266,15 +266,13 @@ function compareResultsByFilePath(a, b) {
  * This function is used primarily by the `--inspect-config` option. For now,
  * we will maintain the existing behavior, which is to search up from the cwd.
  * @param {ESLintOptions} options The ESLint instance options.
- * @param {boolean} allowTS `true` if the `unstable_ts_config` flag is enabled, `false` if it's not.
  * @returns {Promise<{configFilePath:string|undefined;basePath:string}>} Location information for
  *      the config file.
  */
-async function locateConfigFileToUse({ configFile, cwd }, allowTS) {
+async function locateConfigFileToUse({ configFile, cwd }) {
 
     const configLoader = new ConfigLoader({
         cwd,
-        allowTS,
         configFile
     });
 
@@ -469,8 +467,7 @@ class ESLint {
             configFile: processedOptions.configFile,
             ignoreEnabled: processedOptions.ignore,
             ignorePatterns: processedOptions.ignorePatterns,
-            defaultConfigs,
-            allowTS: processedOptions.flags.includes("unstable_ts_config")
+            defaultConfigs
         };
 
         this.#configLoader = processedOptions.flags.includes("unstable_config_lookup_from_file")
diff --git a/lib/shared/flags.js b/lib/shared/flags.js
@@ -10,16 +10,16 @@
  */
 const activeFlags = new Map([
     ["test_only", "Used only for testing."],
-    ["unstable_config_lookup_from_file", "Look up `eslint.config.js` from the file being linted."],
-    ["unstable_ts_config", "Enable TypeScript configuration files."]
+    ["unstable_config_lookup_from_file", "Look up `eslint.config.js` from the file being linted."]
 ]);
 
 /**
  * The set of flags that used to be active but no longer have an effect.
  * @type {Map<string, string>}
  */
 const inactiveFlags = new Map([
-    ["test_only_old", "Used only for testing."]
+    ["test_only_old", "Used only for testing."],
+    ["unstable_ts_config", "This flag is no longer required to enable TypeScript configuration files."]
 ]);
 
 module.exports = {
diff --git a/tests/fixtures/ts-config-files/helper.ts b/tests/fixtures/ts-config-files/helper.ts
@@ -4,42 +4,15 @@
  * and namespaces from other TypeScript files.
  */
 
-export type RuleLevelAndOptions<Options extends any[] = any[]> = Prepend<
-    Partial<Options>,
-    RuleLevel
->;
-
-export type StringSeverity = "off" | "warn" | "error";
+import { Linter } from "eslint";
 
 export const enum Severity {
     "Off" = 0,
     "Warn" = 1,
     "Error" = 2,
 }
 
-export type RuleLevel = Severity | StringSeverity;
-
-export type RuleEntry<Options extends any[] = any[]> =
-    | RuleLevel
-    | RuleLevelAndOptions<Options>;
-
-export interface RulesRecord {
-    [rule: string]: RuleEntry;
-}
-
-export interface FlatConfig<Rules extends RulesRecord = RulesRecord> {
-    name?: string;
-    files?: Array<string | string[]>;
-    ignores?: string[];
-    linterOptions?: {
-        noInlineConfig?: boolean;
-        reportUnusedDisableDirectives?: Severity | StringSeverity | boolean;
-    };
-    processor?: string;
-    plugins?: Record<string, any>;
-    rules?: Partial<Rules>;
-    settings?: Record<string, unknown>;
-}
+export type FlatConfig = Linter.Config;
 
 export namespace ESLintNameSpace {
     export const enum StringSeverity {
diff --git a/tests/lib/eslint/eslint.js b/tests/lib/eslint/eslint.js
