feat: add no-export-default-arrow rule

README.md

@@ -53,9 +53,10 @@ If set `true`, always use explicit return.
 ✅ Set in the `recommended` configuration.\
 🔧 Automatically fixable by the [`--fix` CLI option](https://eslint.org/docs/user-guide/command-line-interface#--fix).
 
-| Name                                                   | Description                         | ⚠️ | 🔧 |
-| :----------------------------------------------------- | :---------------------------------- | :- | :- |
-| [arrow-return-style](docs/rules/arrow-return-style.md) | Enforce arrow function return style | ✅  | 🔧 |
+| Name                                                             | Description                                                                                               | ⚠️ | 🔧 |
+| :--------------------------------------------------------------- | :-------------------------------------------------------------------------------------------------------- | :- | :- |
+| [arrow-return-style](docs/rules/arrow-return-style.md)           | Enforce arrow function return style                                                                       | ✅  | 🔧 |
+| [no-export-default-arrow](docs/rules/no-export-default-arrow.md) | Disallow export default anonymous arrow function<br/>_**Automatically fix using the current file name.**_ | ✅  | 🔧 |
 
 <!-- end auto-generated rules list -->
 <!-- prettier-ignore-end -->

docs/rules/no-export-default-arrow.md

@@ -0,0 +1,23 @@
+# Disallow export default anonymous arrow function<br/>_**Automatically fix using the current file name.**_ (`arrow-return-style/no-export-default-arrow`)
+
+⚠️ This rule _warns_ in the ✅ `recommended` config.
+
+🔧 This rule is automatically fixable by the [`--fix` CLI option](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix).
+
+<!-- end auto-generated rule header -->
+
+If the default export is an anonymous arrow function, it will automatically be converted to a named function using the current file name for exporting.
+
+```ts
+export default () => {
+  // ...
+};
+
+// ↓↓↓↓↓↓↓↓↓↓
+
+const autoFixToCurrentFileName = () => {
+  // ...
+};
+
+export default autoFixToCurrentFileName;
+```

package.json

@@ -54,7 +54,8 @@
     ]
   },
   "dependencies": {
-    "@typescript-eslint/utils": "^6.3.0"
+    "@typescript-eslint/utils": "^6.3.0",
+    "scule": "^1.0.0"
   },
   "devDependencies": {
     "@tsconfig/node18": "^18.2.0",

src/configs/recommended.ts

@@ -6,5 +6,6 @@ export default defineConfig({
   rules: {
     'arrow-body-style': 'off',
     'arrow-return-style/arrow-return-style': 'warn',
+    'arrow-return-style/no-export-default-arrow': 'warn',
   },
 });

src/index.ts

@@ -1,7 +1,8 @@
 import type { Rule } from 'eslint';
 import { name, version } from '../package.json';
 import recommended from './configs/recommended';
-import { arrowReturnStyleRule, RULE_NAME } from './rules/arrow-return-style';
+import { arrowReturnStyleRule, RULE_NAME as arrowReturnStyleRuleName } from './rules/arrow-return-style';
+import { noExportDefaultArrowRule, RULE_NAME as noExportDefaultArrowRuleName } from './rules/no-export-default-arrow';
 import { definePlugin } from './utils';
 
 export default definePlugin({
@@ -15,6 +16,7 @@ export default definePlugin({
   },
 
   rules: {
-    [RULE_NAME]: arrowReturnStyleRule as unknown as Rule.RuleModule,
+    [arrowReturnStyleRuleName]: arrowReturnStyleRule as unknown as Rule.RuleModule,
+    [noExportDefaultArrowRuleName]: noExportDefaultArrowRule as unknown as Rule.RuleModule,
   },
 });

src/rules/no-export-default-arrow.test.ts

@@ -0,0 +1,113 @@
+import { RuleTester } from '@typescript-eslint/rule-tester';
+import dedent from 'dedent';
+import { afterAll, describe, it } from 'vitest';
+import { noExportDefaultArrowRule, RULE_NAME } from './no-export-default-arrow';
+
+RuleTester.afterAll = afterAll;
+RuleTester.describe = describe;
+RuleTester.it = it;
+
+const ruleTester = new RuleTester({
+  parser: '@typescript-eslint/parser',
+
+  parserOptions: {
+    ecmaFeatures: { jsx: true },
+  },
+});
+
+ruleTester.run(RULE_NAME, noExportDefaultArrowRule, {
+  invalid: [
+    {
+      code: dedent`
+        import { useState } from 'react'
+      
+        export default () => {
+          const [, update] = useState({})
+
+          const forceUpdate = () => {
+            update({})
+          }
+
+          return forceUpdate
+        }
+      `,
+
+      errors: [{ messageId: 'disallowExportDefaultArrow' }],
+
+      filename: 'useForceUpdate.ts',
+
+      output: dedent`
+        import { useState } from 'react'
+      
+        const useForceUpdate = () => {
+          const [, update] = useState({})
+
+          const forceUpdate = () => {
+            update({})
+          }
+
+          return forceUpdate
+        }
+
+        export default useForceUpdate
+      `,
+    },
+
+    {
+      code: dedent`
+        export default () => {}
+
+        export const foo = () => 'foo'
+      `,
+
+      errors: [{ messageId: 'disallowExportDefaultArrow' }],
+
+      filename: 'use-mouse.tsx',
+
+      output: dedent`
+        const useMouse = () => {}
+
+        export const foo = () => 'foo'
+
+        export default useMouse
+      `,
+    },
+
+    {
+      code: dedent`
+        export default () => 1
+
+        // line comment
+
+        /* block comment */
+      `,
+
+      errors: [{ messageId: 'disallowExportDefaultArrow' }],
+
+      filename: 'just_for_fun.js',
+
+      output: dedent`
+        const justForFun = () => 1
+
+        // line comment
+
+        /* block comment */
+
+        export default justForFun
+      `,
+    },
+  ],
+
+  valid: [
+    dedent`
+      const foo = () => {
+        return 'foo'
+      }
+
+      export default foo
+    `,
+
+    'const now = () => Date.now()',
+    'export const useQuery = () => {}',
+  ],
+});

src/rules/no-export-default-arrow.ts

@@ -0,0 +1,64 @@
+import path from 'node:path';
+import { AST_NODE_TYPES, ASTUtils, type TSESTree } from '@typescript-eslint/utils';
+import { camelCase } from 'scule';
+import { createRule } from '../utils/create-rule';
+
+export const RULE_NAME = 'no-export-default-arrow';
+
+export const noExportDefaultArrowRule = createRule({
+  create: (context) => {
+    const sourceCode = context.getSourceCode();
+    let program: TSESTree.Program;
+
+    return {
+      ArrowFunctionExpression: (arrowFunction) => {
+        const { body: arrowBody, parent: arrowFunctionParent } = arrowFunction;
+
+        if (arrowFunctionParent.type === AST_NODE_TYPES.ExportDefaultDeclaration) {
+          context.report({
+            fix: (fixer) => {
+              const fixes = [];
+              const lastToken = sourceCode.getLastToken(program, { includeComments: true }) || arrowFunctionParent;
+              const fileName = context.getPhysicalFilename?.() || context.getFilename() || 'namedFunction';
+              const { name: fileNameWithoutExtension } = path.parse(fileName);
+              const funcName = camelCase(fileNameWithoutExtension);
+
+              fixes.push(
+                fixer.replaceText(arrowFunctionParent, `const ${funcName} = ${sourceCode.getText(arrowFunction)}`),
+                fixer.insertTextAfter(lastToken, `\n\nexport default ${funcName}`)
+              );
+
+              return fixes;
+            },
+
+            messageId: 'disallowExportDefaultArrow',
+            node: arrowFunction,
+          });
+        }
+      },
+
+      Program: (node) => (program = node),
+    };
+  },
+
+  defaultOptions: [],
+
+  meta: {
+    docs: {
+      description:
+        'Disallow export default anonymous arrow function<br/>_**Automatically fix using the current file name.**_',
+    },
+
+    fixable: 'code',
+
+    messages: {
+      disallowExportDefaultArrow: 'Disallow export default anonymous arrow function',
+    },
+
+    schema: [],
+
+    type: 'suggestion',
+  },
+
+  name: RULE_NAME,
+});