feat: new to-for-each and to-for-of commands

Author: antfu

README.md

@@ -32,7 +32,7 @@ export default [
 
 ### `to-function`
 
-Provide a quick way to convert an arrow function to a standard function declaration.
+Convert an arrow function to a standard function declaration.
 
 Trigger with `/// to-function` comment (triple slashes) one line above the arrow function.
 
@@ -58,7 +58,7 @@ async function foo(msg: string): void {
 
 ### `to-arrow`
 
-Provide a quick way to convert a standard function declaration to an arrow function.
+Convert a standard function declaration to an arrow function.
 
 Triggers:
 - `/// to-arrow`
@@ -109,6 +109,82 @@ const obj = {
 
 Different from the other commands, the comment will not be removed after transformation to keep the sorting.
 
+### `to-for-each`
+
+Convert for-of/for-in loop to `.forEach()`.
+
+Triggers:
+- `/// to-for-each`
+- `/// foreach`
+
+```js
+/// to-for-each
+for (const item of items) {
+  if (!item)
+    continue
+  console.log(item)
+}
+```
+
+Will be converted to:
+
+```js
+items.forEach((item) => {
+  if (!item)
+    return
+  console.log(item)
+})
+```
+
+For for-in loop:
+
+```js
+/// to-for-each
+for (const key in obj) {
+  if (!obj[key])
+    continue
+  console.log(obj[key])
+}
+```
+
+Will be converted to:
+
+```js
+Object.keys(obj).forEach((key) => {
+  if (!obj[key])
+    return
+  console.log(obj[key])
+})
+```
+
+### `to-for-of`
+
+Convert `.forEach()` to for-of loop.
+
+Triggers:
+
+- `/// to-for-of`
+- `/// forof`
+
+```js
+/// to-for-of
+items.forEach((item) => {
+  if (!item)
+    return
+  console.log(item)
+})
+```
+
+Will be converted to:
+
+```js
+for (const item of items) {
+  if (!item)
+    continue
+  console.log(item)
+}
+```
+
 ## Sponsors
 
 <p align="center">

src/commands/index.ts

@@ -1,9 +1,14 @@
 import { toFunction } from './to-function'
 import { toArrow } from './to-arrow'
 import { keepSorted } from './keep-sorted'
+import { toForEach } from './to-for-each'
+import { toForOf } from './to-for-of'
 
+// @keep-sorted
 export const commands = {
-  toFunction,
-  toArrow,
   keepSorted,
+  toArrow,
+  toForEach,
+  toForOf,
+  toFunction,
 }

src/commands/keep-sorted.test.ts

@@ -32,7 +32,7 @@ const invalids = [
       bar: () => {},
       foo,
     }`,
-    messageId: ['fix'],
+    messageId: ['command-fix'],
   },
   // Array elements
   {
@@ -50,7 +50,7 @@ const invalids = [
       'bar',
       'foo',
     ]`,
-    messageId: ['fix'],
+    messageId: ['command-fix'],
   },
   // Type interface members
   {
@@ -72,7 +72,7 @@ const invalids = [
       parentPath: Path | null
     }
     `,
-    messageId: ['fix'],
+    messageId: ['command-fix'],
   },
   // Type type members
   {
@@ -94,7 +94,7 @@ const invalids = [
       parentPath: Path | null
     }
     `,
-    messageId: ['fix'],
+    messageId: ['command-fix'],
   },
   {
     code: d`
@@ -117,7 +117,7 @@ const invalids = [
         parentPath: null,
       })
     }`,
-    messageId: ['fix'],
+    messageId: ['command-fix'],
   },
 ]
 

src/commands/keep-sorted.ts

@@ -5,7 +5,7 @@ export const keepSorted: Command = {
   name: 'keep-sorted',
   match: /^[\/@:]\s*(keep-sorted|sorted)$/,
   action(ctx) {
-    const node = ctx.getNodeBelow(
+    const node = ctx.findNodeBelow(
       'ObjectExpression',
       'ArrayExpression',
       'TSInterfaceBody',

src/commands/to-arrow.test.ts

@@ -17,7 +17,7 @@ const invalids = [
     /// 2a
     const a = 1`,
     output: null,
-    messageId: 'invalid-command',
+    messageId: 'command-error',
   },
   // Function declaration
   {
@@ -30,7 +30,7 @@ const invalids = [
     export const foo = async <T = 1>(arg: T): Bar => {
       const bar = () => {}
     }`,
-    messageId: ['fix', 'fix'],
+    messageId: ['command-removal', 'command-fix'],
   },
   // Function expression
   {
@@ -43,7 +43,7 @@ const invalids = [
     const bar = async <T = 1>(arg: T): Bar => {
       function baz() {}
     }`,
-    messageId: ['fix', 'fix'],
+    messageId: ['command-removal', 'command-fix'],
   },
   // Object method
   {
@@ -66,7 +66,7 @@ const invalids = [
         return 1
       },
     }`,
-    messageId: ['fix', 'fix'],
+    messageId: ['command-removal', 'command-fix'],
   },
   // Class method
   {
@@ -89,7 +89,7 @@ const invalids = [
         return 1
       }
     }`,
-    messageId: ['fix', 'fix'],
+    messageId: ['command-removal', 'command-fix'],
   },
 ]
 

src/commands/to-arrow.ts

@@ -4,7 +4,7 @@ export const toArrow: Command = {
   name: 'to-arrow',
   match: /^[\/:@]\s*(to-arrow|2a|ta)$/,
   action(ctx) {
-    const fn = ctx.getNodeBelow('FunctionDeclaration', 'FunctionExpression')
+    const fn = ctx.findNodeBelow('FunctionDeclaration', 'FunctionExpression')
     if (!fn)
       return ctx.reportError('Unable to find function declaration to convert')
 

src/commands/to-for-each.test.ts

@@ -0,0 +1,108 @@
+import { RuleTester } from 'eslint'
+import * as tsParser from '@typescript-eslint/parser'
+import { createRuleWithCommands } from '../rule'
+import { toForEach as command } from './to-for-each'
+import { d } from './_test-utils'
+
+const valids = [
+  'const foo = function () {}',
+]
+
+const invalids = [
+  // Basic for-of
+  {
+    code: d`
+    /// to-for-each
+    for (const foo of bar) {
+      if (foo) {
+        continue
+      }
+      else if (1 + 1 === 2) {
+        continue
+      }
+    }`,
+    output: d`
+    bar.forEach(foo => {
+      if (foo) {
+        return
+      }
+      else if (1 + 1 === 2) {
+        return
+      }
+    })`,
+    messageId: ['command-removal', 'command-fix'],
+  },
+  // One-line for-of
+  {
+    code: d`
+    /// to-for-each
+    for (const foo of bar) 
+      count += 1
+    `,
+    output: d`
+    bar.forEach(foo => {
+    count += 1
+    })
+    `,
+    messageId: ['command-removal', 'command-fix'],
+  },
+  // Nested for
+  {
+    code: d`
+    /// to-for-each
+    for (const foo of bar) {
+      for (const baz of foo) {
+        if (foo) {
+          continue
+        }
+      }
+      const fn1 = () => {
+        continue
+      }
+      function fn2() {
+        continue
+      }
+    }`,
+    output: d`
+    bar.forEach(foo => {
+      for (const baz of foo) {
+        if (foo) {
+          continue
+        }
+      }
+      const fn1 = () => {
+        continue
+      }
+      function fn2() {
+        continue
+      }
+    })`,
+    messageId: ['command-removal', 'command-fix'],
+  },
+  // Throw on return statement
+  {
+    code: d`
+    /// to-for-each
+    for (const foo of bar) {
+      return foo
+    }`,
+    output: null,
+    messageId: ['command-error', 'command-error-cause'],
+  },
+]
+
+const ruleTester: RuleTester = new RuleTester({
+  languageOptions: {
+    parser: tsParser,
+  },
+})
+
+ruleTester.run(command.name, createRuleWithCommands([command]) as any, {
+  valid: valids,
+  invalid: invalids.map(i => ({
+    code: i.code,
+    output: i.output,
+    errors: (Array.isArray(i.messageId) ? i.messageId : [i.messageId])
+      .map(id => ({ messageId: id })),
+  })),
+})