feat: add should-be-fine support for flat configs (#181)

* feat: add should-be-fine support for flat configs

* refactor: use `Object.fromEntries` instead of `reduce`

.eslint-doc-generatorrc.js

@@ -3,7 +3,13 @@ const { prettier: prettierRC } = require('./package.json');
 
 /** @type {import('eslint-doc-generator').GenerateOptions} */
 const config = {
-  ignoreConfig: ['all'],
+  ignoreConfig: [
+    'all',
+    'flat/all',
+    'flat/recommended',
+    'flat/style',
+    'flat/snapshots',
+  ],
   ruleDocTitleFormat: 'desc-parens-name',
   ruleDocSectionInclude: ['Rule details'],
   ruleListColumns: [

README.md

@@ -22,6 +22,15 @@ $ yarn add --dev eslint eslint-plugin-jest-extended
 
 ## Usage
 
+> [!NOTE]
+>
+> `eslint.config.js` is supported, though most of the plugin documentation still
+> currently uses `.eslintrc` syntax.
+>
+> Refer to the
+> [ESLint documentation on the new configuration file format](https://eslint.org/docs/latest/use/configure/configuration-files-new)
+> for more.
+
 Add `jest-extended` to the plugins section of your `.eslintrc` configuration
 file. You can omit the `eslint-plugin-` prefix:
 
@@ -61,6 +70,22 @@ If you want to enable all rules instead of only some you can do so by adding the
 }
 ```
 
+To enable this configuration with `eslint.config.js`, use
+`jestExtended.configs['flat/all']`:
+
+```js
+const jestExtended = require('eslint-plugin-jest-extended');
+
+module.exports = [
+  {
+    files: [
+      /* glob matching your test files */
+    ],
+    ...jestExtended.configs['flat/all'],
+  },
+];
+```
+
 Note that the `all` configuration may change in any release and is thus unsuited
 for installations requiring long-term consistency.
 

src/__tests__/__snapshots__/rules.test.ts.snap

@@ -14,6 +14,34 @@ exports[`rules should export configs that refer to actual rules 1`] = `
       "jest-extended/prefer-to-have-been-called-once": "error",
     },
   },
+  "flat/all": {
+    "plugins": {
+      "jest-extended": ObjectContaining {
+        "meta": {
+          "name": "eslint-plugin-jest-extended",
+          "version": Any<String>,
+        },
+      },
+    },
+    "rules": {
+      "jest-extended/prefer-to-be-array": "error",
+      "jest-extended/prefer-to-be-false": "error",
+      "jest-extended/prefer-to-be-object": "error",
+      "jest-extended/prefer-to-be-true": "error",
+      "jest-extended/prefer-to-have-been-called-once": "error",
+    },
+  },
+  "flat/recommended": {
+    "plugins": {
+      "jest-extended": ObjectContaining {
+        "meta": {
+          "name": "eslint-plugin-jest-extended",
+          "version": Any<String>,
+        },
+      },
+    },
+    "rules": {},
+  },
   "recommended": {
     "plugins": [
       "jest-extended",

src/__tests__/rules.test.ts

@@ -29,15 +29,37 @@ describe('rules', () => {
   });
 
   it('should export configs that refer to actual rules', () => {
+    const expectJestExtendedPlugin = expect.objectContaining({
+      meta: {
+        name: 'eslint-plugin-jest-extended',
+        version: expect.any(String),
+      },
+    });
+
     const recommendedConfigs = plugin.configs;
 
-    expect(recommendedConfigs).toMatchSnapshot();
-    expect(Object.keys(recommendedConfigs)).toEqual(['all', 'recommended']);
+    expect(recommendedConfigs).toMatchSnapshot({
+      'flat/recommended': {
+        plugins: { 'jest-extended': expectJestExtendedPlugin },
+      },
+      'flat/all': {
+        plugins: { 'jest-extended': expectJestExtendedPlugin },
+      },
+    });
+    expect(Object.keys(recommendedConfigs)).toEqual([
+      'all',
+      'recommended',
+      'flat/all',
+      'flat/recommended',
+    ]);
     expect(Object.keys(recommendedConfigs.all.rules)).toHaveLength(
       ruleNames.length,
     );
+    expect(Object.keys(recommendedConfigs['flat/all'].rules)).toHaveLength(
+      ruleNames.length,
+    );
     const allConfigRules = Object.values(recommendedConfigs)
-      .map(config => Object.keys(config.rules))
+      .map(config => Object.keys(config.rules ?? {}))
       .reduce((previousValue, currentValue) => [
         ...previousValue,
         ...currentValue,

src/index.ts

@@ -1,6 +1,10 @@
 import { readdirSync } from 'fs';
 import { join, parse } from 'path';
 import { TSESLint, TSESTree } from '@typescript-eslint/utils';
+import {
+  name as packageName,
+  version as packageVersion,
+} from '../package.json';
 
 type RuleModule = TSESLint.RuleModule<string, unknown[]> & {
   meta: Required<Pick<TSESLint.RuleMetaData<string>, 'docs'>>;
@@ -36,47 +40,49 @@ const importDefault = (moduleName: string) =>
 const rulesDir = join(__dirname, 'rules');
 const excludedFiles = ['__tests__', 'utils'];
 
-const rules = readdirSync(rulesDir)
-  .map(rule => parse(rule).name)
-  .filter(rule => !excludedFiles.includes(rule))
-  .reduce<Record<string, RuleModule>>(
-    (acc, curr) => ({
-      ...acc,
-      [curr]: importDefault(join(rulesDir, curr)) as RuleModule,
-    }),
-    {},
-  );
+const rules = Object.fromEntries(
+  readdirSync(rulesDir)
+    .map(rule => parse(rule).name)
+    .filter(rule => !excludedFiles.includes(rule))
+    .map(rule => [rule, importDefault(join(rulesDir, rule)) as RuleModule]),
+);
 
-const recommendedRules = Object.entries(rules)
-  .filter(([, rule]) => rule.meta.docs.recommended)
-  .reduce(
-    /* istanbul ignore next */
-    (acc, [name, rule]) => ({
-      ...acc,
-      [`jest-extended/${name}`]: rule.meta.docs.recommended,
-    }),
-    {},
-  );
+const recommendedRules = {} satisfies Record<string, TSESLint.Linter.RuleLevel>;
 
-const allRules = Object.entries(rules)
-  .filter(([, rule]) => !rule.meta.deprecated)
-  .reduce(
-    (acc, [name]) => ({
-      ...acc,
-      [`jest-extended/${name}`]: 'error',
-    }),
-    {},
-  );
+const allRules = Object.fromEntries<TSESLint.Linter.RuleLevel>(
+  Object.entries(rules)
+    .filter(([, rule]) => !rule.meta.deprecated)
+    .map(([name]) => [`jest-extended/${name}`, 'error']),
+);
 
-const createConfig = (rules: Record<string, TSESLint.Linter.RuleLevel>) => ({
+const plugin = {
+  meta: { name: packageName, version: packageVersion },
+  // ugly cast for now to keep TypeScript happy since
+  // we don't have types for flat config yet
+  configs: {} as Record<
+    'all' | 'recommended' | 'flat/all' | 'flat/recommended',
+    Pick<Required<TSESLint.Linter.Config>, 'rules'>
+  >,
+  rules,
+};
+
+const createRCConfig = (rules: Record<string, TSESLint.Linter.RuleLevel>) => ({
   plugins: ['jest-extended'],
   rules,
 });
 
-export = {
-  configs: {
-    all: createConfig(allRules),
-    recommended: createConfig(recommendedRules),
-  },
+const createFlatConfig = (
+  rules: Record<string, TSESLint.Linter.RuleLevel>,
+) => ({
+  plugins: { 'jest-extended': plugin },
   rules,
+});
+
+plugin.configs = {
+  all: createRCConfig(allRules),
+  recommended: createRCConfig(recommendedRules),
+  'flat/all': createFlatConfig(allRules),
+  'flat/recommended': createFlatConfig(recommendedRules),
 };
+
+export = plugin;