feat: migrate to TypeScript with 100% compatibility

.all-contributorsrc

@@ -346,7 +346,10 @@
       "name": "Jonathan Rehm",
       "avatar_url": "https://avatars.githubusercontent.com/u/999845?v=4",
       "profile": "https://jonathan.rehm.me/",
-      "contributions": ["bug", "code"]
+      "contributions": [
+        "bug",
+        "code"
+      ]
     },
     {
       "login": "gwhitney",

.github/workflows/ci.yml

@@ -21,21 +21,21 @@ jobs:
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
-    - name: Use Node.js ${{ matrix.node }}
-      uses: actions/setup-node@v4
-      with:
-        node-version: ${{ matrix.node }}
-        cache: yarn
+      - name: Use Node.js ${{ matrix.node }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+          cache: yarn
 
-    - name: Install dependencies
-      run: yarn --immutable
+      - name: Install dependencies
+        run: yarn --immutable
 
-    - name: Lint, test, and build
-      run: yarn start validate
+      - name: Lint, test, and build
+        run: yarn start validate
 
-    - name: Check test coverage
-      uses: codecov/codecov-action@v5
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
+      - name: Check test coverage
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos

.gitignore

@@ -8,3 +8,4 @@ dist
 .yarn/*
 !.yarn/releases
 !.yarn/plugins
+!test/fixtures/paths/node_modules

.prettierignore

@@ -1,6 +1 @@
 .yarn
-node_modules
-.nyc_output
-coverage
-dist
-tests/fixtures/

.prettierrc.mjs

@@ -0,0 +1,21 @@
+// @ts-check
+
+/** @import { Config, Plugin } from 'prettier' */
+
+import base from '@1stg/prettier-config/semi';
+import * as jsdoc from 'prettier-plugin-jsdoc';
+import * as jsdocType from 'prettier-plugin-jsdoc-type';
+import * as svelte from 'prettier-plugin-svelte';
+
+/** @type {Config} */
+const config = {
+  ...base,
+  plugins: [
+    .../** @type {Plugin[]} */ (base.plugins),
+    jsdoc,
+    jsdocType,
+    svelte,
+  ],
+};
+
+export default config;

.yarnrc.yml

@@ -5,6 +5,6 @@ nodeLinker: node-modules
 plugins:
   - checksum: 37b2361b1502b2054e6779788c0e9bdd6a90ce49852a8cad2feda79b0614ec94f06fb6e78951f5f95429c610d7934dd077caa47413a0227378a102c55161616d
     path: .yarn/plugins/plugin-prepare-lifecycle.cjs
-    spec: "https://github.com/un-es/yarn-plugin-prepare-lifecycle/releases/download/v0.0.1/index.js"
+    spec: 'https://github.com/un-es/yarn-plugin-prepare-lifecycle/releases/download/v0.0.1/index.js'
 
 yarnPath: .yarn/releases/yarn-4.9.1.cjs

other/EXAMPLES.md → EXAMPLES.md

@@ -23,20 +23,21 @@ gulp.task('js:format', function () {
 
 ```js
 var through = require('through2');
+var PluginError = require('plugin-error');
 var prettierEslint = require('prettier-eslint');
 
 const options = {
   eslintConfig: {
     parserOptions: {
-      ecmaVersion: 7
+      ecmaVersion: 7,
     },
     rules: {
-      semi: ['error', 'never']
-    }
+      semi: ['error', 'never'],
+    },
   },
   prettierOptions: {
-    bracketSpacing: true
-  }
+    bracketSpacing: true,
+  },
 };
 
 module.exports = function () {
@@ -49,14 +50,14 @@ module.exports = function () {
 
     if (file.isStream()) {
       return callback(
-        new utils.PluginError('prettier-eslint', "doesn't support Streams")
+        new PluginError('prettier-eslint', "doesn't support Streams"),
       );
     }
 
     const sourceCode = file.contents.toString();
     const formatted = prettierEslint({
-      ...config,
-      text: sourceCode
+      ...options,
+      text: sourceCode,
     });
 
     file.contents = new Buffer(formatted, encoding);

README.md

@@ -48,7 +48,7 @@ npm install --save-dev prettier-eslint
 
 ### Example
 
-```javascript
+```js
 const format = require('prettier-eslint');
 
 // notice, no semicolon in the original text
@@ -58,18 +58,18 @@ const options = {
   text: sourceCode,
   eslintConfig: {
     parserOptions: {
-      ecmaVersion: 7
+      ecmaVersion: 7,
     },
     rules: {
-      semi: ['error', 'never']
-    }
+      semi: ['error', 'never'],
+    },
   },
   prettierOptions: {
-    bracketSpacing: true
+    bracketSpacing: true,
   },
   fallbackPrettierOptions: {
-    singleQuote: false
-  }
+    singleQuote: false,
+  },
 };
 
 const formatted = await format(options);
@@ -150,15 +150,15 @@ This allows you to use `eslint` to look for bugs and/or bad practices, and use
 
 ## Capturing ESLint messages
 
-```javascript
+```js
 const { analyze } = require('prettier-eslint');
 
 const text = 'var x = 0;';
 const result = await analyze({
   text,
   eslintConfig: {
-    rules: { 'no-var': 'error' }
-  }
+    rules: { 'no-var': 'error' },
+  },
 });
 console.log(result.messages);
 ```
@@ -210,7 +210,7 @@ the inference is done for each option (what rule(s) are referenced, etc.) and
 ESLint disabled entirely via `/* eslint-disable */` then prettier options will
 fall back to the `prettier` defaults:
 
-```javascript
+```js
 {
   printWidth: 80,
   tabWidth: 2,
@@ -291,8 +291,8 @@ solutions.
 - [`prettier-atom`][atom-plugin] - Atom plugin (check the "ESlint integration"
   checkbox in settings)
 - [`vs-code-prettier-eslint`][vscode-plugin] - Visual Studio Code plugin
-- [`eslint-plugin-prettier`](https://github.com/not-an-aardvark/eslint-plugin-prettier) -
-  ESLint plugin. While prettier-eslint uses `eslint --fix` to change the output of `prettier`, eslint-plugin-prettier keeps the `prettier` output as-is and integrates it with the regular ESLint workflow.
+- [`eslint-plugin-prettier`](https://github.com/prettier/eslint-plugin-prettier) -
+  ESLint plugin. While `prettier-eslint` uses `eslint --fix` to change the output of `prettier`, `eslint-plugin-prettier` keeps the `prettier` output as-is and integrates it with the regular ESLint workflow.
 - [`prettier-eslint-webpack-plugin`](https://github.com/danielterwiel/prettier-eslint-webpack-plugin) -
   Prettier ESlint Webpack Plugin
 

__mocks__/eslint.ts

@@ -0,0 +1,104 @@
+/**
+ * This mock file is so eslint doesn't attempt to actually search around the
+ * file system for stuff, we can not use `.ts` because it's called by
+ * `test/fixtures/node_modules/eslint/index.js`
+ */
+
+import eslint_, { type ESLint as ESLint_ } from 'eslint';
+
+import type { ESLintLintText, MockESLint } from '../mock.js';
+
+import type { ESLintConfig } from 'prettier-eslint';
+
+const eslint = jest.requireActual<typeof eslint_>('eslint');
+
+const { ESLint } = eslint;
+
+const mockCalculateConfigForFileSpy = jest.fn(mockCalculateConfigForFile);
+
+Object.assign(mockCalculateConfigForFileSpy, { overrides: {} });
+
+const mockLintTextSpy = jest.fn(mockLintText);
+
+export = Object.assign(eslint, {
+  ESLint: jest.fn(MockESLint),
+  mock: {
+    calculateConfigForFile: mockCalculateConfigForFileSpy,
+    lintText: mockLintTextSpy,
+  },
+});
+
+function MockESLint(options: ESLint_.Options): MockESLint {
+  globalThis.__PRETTIER_ESLINT_TEST_STATE__.eslintPath = __filename;
+  const eslintInstance = new ESLint(options) as MockESLint;
+  eslintInstance.calculateConfigForFile = mockCalculateConfigForFileSpy;
+  // eslint-disable-next-line @typescript-eslint/unbound-method
+  eslintInstance._originalLintText = eslintInstance.lintText;
+  eslintInstance.lintText = mockLintTextSpy;
+  return eslintInstance;
+}
+
+MockESLint.prototype = Object.create(ESLint.prototype) as ESLint_;
+
+/**
+ * @throws If `throwError` is specifically set on the spy, or if the filePath is
+ *   not handled
+ */
+// eslint-disable-next-line @typescript-eslint/require-await
+async function mockCalculateConfigForFile(
+  filePath: string,
+): Promise<ESLintConfig> {
+  if (
+    'throwError' in mockCalculateConfigForFileSpy &&
+    mockCalculateConfigForFileSpy.throwError instanceof Error
+  ) {
+    throw mockCalculateConfigForFileSpy.throwError;
+  }
+  if (!filePath) {
+    return {
+      rules: {},
+    };
+  }
+  if (filePath.includes('default-config')) {
+    return {
+      rules: {
+        semi: [2, 'never'],
+        'max-len': [2, 120, 2],
+        indent: [2, 2, { SwitchCase: 1 }],
+        quotes: [
+          2,
+          'single',
+          { avoidEscape: true, allowTemplateLiterals: true },
+        ],
+        'comma-dangle': [
+          2,
+          {
+            arrays: 'always-multiline',
+            objects: 'always-multiline',
+            imports: 'always-multiline',
+            exports: 'always-multiline',
+            functions: 'always-multiline',
+          },
+        ],
+        'arrow-parens': [2, 'as-needed'],
+      },
+    };
+  }
+  if (filePath.includes('fixtures/paths')) {
+    return { rules: {} };
+  }
+  throw new Error(
+    `Your mock filePath (${filePath})` +
+      ' does not have a handler for finding the config',
+  );
+}
+
+function mockLintText(this: MockESLint, ...args: Parameters<ESLintLintText>) {
+  if (
+    'throwError' in mockLintTextSpy &&
+    mockLintTextSpy.throwError instanceof Error
+  ) {
+    throw mockLintTextSpy.throwError;
+  }
+  return this._originalLintText(...args);
+}

__mocks__/fs.ts

@@ -0,0 +1,19 @@
+import type Fs_ from 'node:fs';
+
+type Fs = typeof Fs_;
+
+const fs = jest.requireActual<Fs>('fs');
+
+// eslint-disable-next-line prefer-object-spread -- typing issue
+export = Object.assign({}, fs, {
+  readFileSync: jest.fn((filename: string) => {
+    if (filename.endsWith('package.json')) {
+      return '{"name": "fake", "version": "0.0.0", "prettier": {}}';
+    }
+    if (/\.[jt]s$/.test(filename)) {
+      return 'var fake = true';
+    }
+
+    return '';
+  }),
+});