.github/workflows/NodeCI.yml

@@ -11,11 +11,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v3
-        with:
-          node-version: 18
+      - uses: actions/setup-node@v4
       - name: Install Packages
-        run: npm i
+        run: npm i -f
       - name: Build
         run: npm run build
       - name: Lint
@@ -25,6 +23,8 @@ jobs:
     strategy:
       matrix:
         include:
+          - eslint: ^9.0.0-0
+            node: 20
           - eslint: 8
             node: 20
           - eslint: 8
@@ -44,11 +44,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Use Node.js ${{ matrix.node }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}
       - name: Install Packages
-        run: npm i
+        run: npm i -f
       - name: Install ESLint ${{ matrix.eslint }}
         run: |+
           npm i -D eslint@${{ matrix.eslint }} -f

.github/workflows/Release.yml

@@ -21,9 +21,9 @@ jobs:
           # This makes Actions fetch all Git history so that Changesets can generate changelogs with the correct commits
           fetch-depth: 0
       - name: Setup Node.js
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
       - name: Install Dependencies
-        run: npm i
+        run: npm i -f
       - name: Create Release Pull Request or Publish to npm
         id: changesets
         uses: changesets/action@v1

.vscode/settings.json

@@ -11,6 +11,6 @@
   ],
   "typescript.tsdk": "./node_modules/typescript/lib",
   "editor.codeActionsOnSave": {
-    "source.fixAll.eslint": true
+    "source.fixAll.eslint": "explicit"
   }
 }

CHANGELOG.md

@@ -1,5 +1,15 @@
 # eslint-compat-utils
 
+## 0.2.0
+
+### Minor Changes
+
+- feat!: move `getESLint` to `./eslint` namespace ([#16](https://github.com/ota-meshi/eslint-compat-utils/pull/16))
+
+- feat: improve getESLint ([#16](https://github.com/ota-meshi/eslint-compat-utils/pull/16))
+
+- feat: add getLinter ([#16](https://github.com/ota-meshi/eslint-compat-utils/pull/16))
+
 ## 0.1.2
 
 ### Patch Changes

README.md

@@ -7,7 +7,7 @@ Provides an API for ESLint custom rules that is compatible with the latest ESLin
 ## Installation
 
 ```bash
-npm install --save-dev eslint-compat-utils
+npm install eslint-compat-utils
 ```
 
 ## Usage

package.json

@@ -1,16 +1,31 @@
 {
   "name": "eslint-compat-utils",
-  "version": "0.1.2",
+  "version": "0.2.0",
   "description": "Provides an API for ESLint custom rules that is compatible with the latest ESLint even when using older ESLint.",
   "engines": {
     "node": ">=12"
   },
   "exports": {
     ".": {
-      "types": "./index.d.ts",
+      "types": "./dist/index.d.ts",
       "import": "./dist/index.mjs",
       "require": "./dist/index.cjs"
     },
+    "./eslint": {
+      "types": "./dist/eslint.d.ts",
+      "import": "./dist/eslint.mjs",
+      "require": "./dist/eslint.cjs"
+    },
+    "./linter": {
+      "types": "./dist/linter.d.ts",
+      "import": "./dist/linter.mjs",
+      "require": "./dist/linter.cjs"
+    },
+    "./rule-tester": {
+      "types": "./dist/rule-tester.d.ts",
+      "import": "./dist/rule-tester.mjs",
+      "require": "./dist/rule-tester.cjs"
+    },
     "./package.json": "./package.json"
   },
   "main": "./dist/index.cjs",
@@ -59,11 +74,11 @@
     "@svitejs/changesets-changelog-github-compact": "^1.1.0",
     "@types/eslint": "^8.44.3",
     "@types/mocha": "^10.0.0",
-    "@types/node": "^18.11.0",
+    "@types/node": "^20.0.0",
     "@typescript-eslint/eslint-plugin": "^6.7.4",
     "@typescript-eslint/parser": "^6.7.4",
     "esbuild-register": "^3.5.0",
-    "eslint": "^8.51.0",
+    "eslint": "^8.56.0",
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-json-schema-validator": "^4.6.0",
     "eslint-plugin-jsonc": "^2.9.0",
@@ -75,5 +90,8 @@
     "nyc": "^15.1.0",
     "prettier": "^3.0.3",
     "unbuild": "^2.0.0"
+  },
+  "dependencies": {
+    "semver": "^7.5.4"
   }
 }

src/eslint.ts

@@ -1,15 +1,79 @@
 import * as eslint from "eslint";
+import * as semver from "semver";
+import { convertConfigToRc } from "./lib/convert-config";
 
+let cacheESLint: typeof eslint.ESLint | undefined;
 /**
  * Get ESLint class
  */
 export function getESLint(): typeof eslint.ESLint {
-  return eslint.ESLint ?? getESLintClassForV6();
+  return (cacheESLint ??= getESLintInternal());
+
+  /** Internal */
+  function getESLintInternal(): typeof eslint.ESLint {
+    if (semver.gte(eslint.Linter.version, "9.0.0-0")) {
+      return (cacheESLint = eslint.ESLint);
+    }
+    return (cacheESLint = eslint.ESLint
+      ? getESLintClassForV8()
+      : getESLintClassForV6());
+  }
+}
+
+/** Create compat ESLint class for eslint v8  */
+function getESLintClassForV8(
+  // eslint-disable-next-line @typescript-eslint/naming-convention -- class name
+  BaseESLintClass = eslint.ESLint,
+): typeof eslint.ESLint {
+  return class ESLintForV8 extends BaseESLintClass {
+    public static get version() {
+      return BaseESLintClass.version;
+    }
+
+    public constructor(options: any) {
+      super(adjustOptions(options));
+    }
+  };
+
+  /** Adjust options */
+  function adjustOptions(options: any) {
+    const {
+      baseConfig,
+      overrideConfig: originalOverrideConfig,
+      overrideConfigFile,
+      ...newOptions
+    } = options || {};
+
+    if (baseConfig) {
+      newOptions.baseConfig = convertConfigToRc(baseConfig);
+    }
+    if (originalOverrideConfig) {
+      const { plugins, ...overrideConfig } = originalOverrideConfig;
+      // Remove unsupported options
+      delete overrideConfig.files;
+      delete overrideConfig.processor;
+
+      newOptions.overrideConfig = convertConfigToRc(overrideConfig);
+
+      if (plugins) {
+        newOptions.overrideConfig.plugins = Object.keys(plugins);
+        newOptions.plugins = plugins;
+      }
+    }
+    if (overrideConfigFile) {
+      if (overrideConfigFile === true) {
+        newOptions.useEslintrc = false;
+      } else {
+        newOptions.overrideConfigFile = overrideConfigFile;
+      }
+    }
+    return newOptions;
+  }
 }
 
-/** @returns {typeof eslint.ESLint} */
-function getESLintClassForV6() {
-  // eslint-disable-next-line @typescript-eslint/naming-convention -- calss name
+/** Create compat ESLint class for eslint v6  */
+function getESLintClassForV6(): typeof eslint.ESLint {
+  // eslint-disable-next-line @typescript-eslint/naming-convention -- class name
   const CLIEngine = (eslint as any).CLIEngine;
   class ESLintForV6 {
     private readonly engine: any;
@@ -31,8 +95,7 @@ function getESLintClassForV6() {
         ...otherOptions
       } = options || {};
 
-      /** @type {eslint.CLIEngine.Options} */
-      const newOptions = {
+      const cliEngineOptions = {
         fix: Boolean(fix),
         reportUnusedDisableDirectives: reportUnusedDisableDirectives
           ? reportUnusedDisableDirectives !== "off"
@@ -52,7 +115,7 @@ function getESLintClassForV6() {
           : undefined,
         ...overrideConfig,
       };
-      this.engine = new CLIEngine(newOptions);
+      this.engine = new CLIEngine(cliEngineOptions);
 
       for (const [name, plugin] of Object.entries(pluginsMap || {})) {
         this.engine.addPlugin(name, plugin);
@@ -87,5 +150,5 @@ function getESLintClassForV6() {
     }
   }
 
-  return ESLintForV6;
+  return getESLintClassForV8(ESLintForV6 as any);
 }

src/index.ts

@@ -2,4 +2,3 @@ export { getSourceCode } from "./get-source-code";
 export { getCwd } from "./get-cwd";
 export { getFilename } from "./get-filename";
 export { getPhysicalFilename } from "./get-physical-filename";
-export { getESLint } from "./eslint";

src/lib/convert-config.ts

@@ -0,0 +1,109 @@
+import * as eslint from "eslint";
+import * as semver from "semver";
+import type { LinterConfigForV8 } from "../v8-props";
+import { createRequire } from "module";
+
+/** Convert to eslintrc config from v9 config  */
+export function convertConfigToRc(
+  config: eslint.Linter.FlatConfig | eslint.Linter.FlatConfig[],
+  linter?: {
+    defineRule?: (typeof eslint.Linter)["prototype"]["defineRule"];
+    defineParser?: (typeof eslint.Linter)["prototype"]["defineParser"];
+  },
+): LinterConfigForV8 {
+  if (Array.isArray(config)) {
+    throw new Error("Array config is not supported.");
+  }
+  const {
+    languageOptions: originalLanguageOptions,
+    plugins,
+    ...newConfig
+  } = config;
+  if (originalLanguageOptions) {
+    const {
+      parser,
+      globals,
+      parserOptions,
+      ecmaVersion,
+      sourceType,
+      ...languageOptions
+    } = originalLanguageOptions;
+    (newConfig as LinterConfigForV8).parserOptions = {
+      ...(!ecmaVersion || ecmaVersion === "latest"
+        ? { ecmaVersion: getLatestEcmaVersion() }
+        : { ecmaVersion }),
+      ...(sourceType ? { sourceType } : { sourceType: "module" }),
+      ...languageOptions,
+      ...parserOptions,
+      ...(newConfig as LinterConfigForV8).parserOptions,
+    };
+    if (globals) {
+      (newConfig as LinterConfigForV8).globals = {
+        ...globals,
+        ...(newConfig as LinterConfigForV8).globals,
+      };
+    }
+    if (parser && !(newConfig as LinterConfigForV8).parser) {
+      const parserName = getParserName(parser);
+      (newConfig as LinterConfigForV8).parser = parserName;
+      linter?.defineParser?.(parserName, parser);
+    }
+  }
+  if (plugins) {
+    for (const [pluginName, plugin] of Object.entries(plugins)) {
+      for (const [ruleName, rule] of Object.entries(plugin.rules || {})) {
+        linter?.defineRule?.(`${pluginName}/${ruleName}`, rule as any);
+      }
+    }
+  }
+  (newConfig as LinterConfigForV8).env = {
+    es6: true,
+    ...(newConfig as LinterConfigForV8).env,
+  };
+  return newConfig as LinterConfigForV8;
+}
+
+/** Resolve parser name */
+function getParserName(parser: any) {
+  const name = parser.meta?.name || parser.name;
+  if (name === "typescript-eslint/parser") {
+    return safeRequireResolve("@typescript-eslint/parser");
+  } else if (
+    name == null &&
+    parser === safeRequire("@typescript-eslint/parser")
+  )
+    return safeRequireResolve("@typescript-eslint/parser");
+  return safeRequireResolve(name);
+}
+
+/** Get module */
+function safeRequire(name: string) {
+  try {
+    return createRequire(`${process.cwd()}/__placeholder__.js`)(name);
+  } catch {
+    return undefined;
+  }
+}
+
+/** Get module path */
+function safeRequireResolve(name: string) {
+  try {
+    return createRequire(`${process.cwd()}/__placeholder__.js`).resolve(name);
+  } catch {
+    return name;
+  }
+}
+
+/** Get latest ecmaVersion */
+function getLatestEcmaVersion() {
+  const eslintVersion = eslint.Linter.version;
+  return semver.gte(eslintVersion, "8.0.0")
+    ? "latest"
+    : semver.gte(eslintVersion, "7.8.0")
+      ? 2021
+      : semver.gte(eslintVersion, "6.2.0")
+        ? 2020
+        : semver.gte(eslintVersion, "5.0.0")
+          ? 2019
+          : 2018;
+}