Package CLI code as ES module to allow import()

bin.mjs

@@ -0,0 +1,11 @@
+#!/usr/bin/env node
+
+import { UserError, cli, help } from './dist/cli.mjs'
+
+cli(process.stdin, error => {
+  if (error instanceof UserError) {
+    if (error.code === UserError.ARGS) console.error(`${help}\n`)
+    console.error(error.message)
+    process.exitCode = error.code
+  } else if (error) throw error
+})

config/jest.config.js

@@ -12,10 +12,14 @@ switch (process.env.npm_lifecycle_event) {
     console.log('Testing build output from dist/')
     moduleNameMapper = {
       '^yaml$': '<rootDir>/dist/index.js',
-      '^yaml/cli$': '<rootDir>/dist/cli.js',
+      '^yaml/cli$': '<rootDir>/dist/cli.mjs',
       '^yaml/util$': '<rootDir>/dist/util.js',
       '^../src/test-events$': '<rootDir>/dist/test-events.js'
     }
+    transform['[/\\\\]dist[/\\\\].*\\.mjs$'] = [
+      'babel-jest',
+      { configFile: './config/babel.config.js' }
+    ]
     break
 
   case 'test':

config/rollup.node-config.mjs

@@ -1,30 +1,26 @@
 import { chmod, stat } from 'node:fs/promises'
 import typescript from '@rollup/plugin-typescript'
 
-export default {
-  input: {
-    cli: 'src/cli.ts',
-    index: 'src/index.ts',
-    'test-events': 'src/test-events.ts',
-    util: 'src/util.ts'
+export default [
+  {
+    input: {
+      index: 'src/index.ts',
+      'test-events': 'src/test-events.ts',
+      util: 'src/util.ts'
+    },
+    output: {
+      dir: 'dist',
+      format: 'cjs',
+      esModule: false,
+      preserveModules: true
+    },
+    plugins: [typescript()],
+    treeshake: { moduleSideEffects: false, propertyReadSideEffects: false }
   },
-  output: {
-    dir: 'dist',
-    format: 'cjs',
-    esModule: false,
-    preserveModules: true
-  },
-  external: ['node:path', 'node:util'],
-  plugins: [
-    typescript(),
-    {
-      async writeBundle() {
-        // chmod a+x dist/cli.js
-        const file = 'dist/cli.js'
-        const prev = await stat(file)
-        await chmod(file, prev.mode | 0o111)
-      }
-    }
-  ],
-  treeshake: { moduleSideEffects: false, propertyReadSideEffects: false }
-}
+  {
+    input: 'src/cli.ts',
+    output: { file: 'dist/cli.mjs' },
+    external: () => true,
+    plugins: [typescript()]
+  }
+]

package.json

@@ -18,7 +18,7 @@
   ],
   "type": "commonjs",
   "main": "./dist/index.js",
-  "bin": "./dist/cli.js",
+  "bin": "./bin.mjs",
   "browser": {
     "./dist/index.js": "./browser/index.js",
     "./dist/util.js": "./browser/dist/util.js",

src/cli.ts

@@ -1,5 +1,3 @@
-#!/usr/bin/env node
-
 import { resolve } from 'node:path'
 import { parseArgs } from 'node:util'
 
@@ -12,7 +10,7 @@ import { type Document } from './doc/Document.js'
 import { prettifyError } from './errors.js'
 import { visit, type visitor } from './visit.js'
 
-const help = `\
+export const help = `\
 yaml: A command-line YAML processor and inspector
 
 Reads stdin and writes output to stdout and errors & warnings to stderr.
@@ -34,7 +32,7 @@ Additional options for bare "yaml" command:
   --visit, -v   Apply a visitor to each document (requires a path to import)
   --yaml 1.1    Set the YAML version. (default: 1.2)`
 
-class UserError extends Error {
+export class UserError extends Error {
   static ARGS = 2
   static SINGLE = 3
   code: number
@@ -44,17 +42,7 @@ class UserError extends Error {
   }
 }
 
-/* istanbul ignore if */
-if (require.main === module)
-  // eslint-disable-next-line @typescript-eslint/no-floating-promises
-  main(process.stdin, error => {
-    if (error instanceof UserError) {
-      console.error(`${help}\n\n${error.message}`)
-      process.exitCode = error.code
-    } else if (error) throw error
-  })
-
-export async function main(
+export async function cli(
   stdin: NodeJS.ReadableStream,
   done: (error?: Error) => void,
   argv?: string[]

tests/cli.ts

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-floating-promises */
 
 import { Readable } from 'node:stream'
-import { main } from 'yaml/cli'
+import { cli } from 'yaml/cli'
 
 const [major] = process.versions.node.split('.')
 const skip = Number(major) < 20
@@ -31,7 +31,7 @@ const skip = Number(major) < 20
     test(name, done => {
       stdout.length = 0
       stderr.length = 0
-      main(
+      cli(
         Readable.from([input]),
         error => {
           try {
@@ -56,7 +56,7 @@ const skip = Number(major) < 20
     test(name, done => {
       stderr.length = 0
       let doned = false
-      main(
+      cli(
         Readable.from([input]),
         error => {
           if (doned) return