chore: revert "fix: support ESM projects using TypeScript with ts-node/esm"

packages/data-context/src/actions/MigrationActions.ts

@@ -32,9 +32,6 @@ import {
 } from '../sources/migration'
 import { makeCoreData } from '../data'
 import { LegacyPluginsIpc } from '../data/LegacyPluginsIpc'
-import { hasTypeScriptInstalled } from '../util'
-
-const tsNode = require.resolve('@packages/server/lib/plugins/child/register_ts_node')
 
 export function getConfigWithDefaults (legacyConfig: any) {
   const newConfig = _.cloneDeep(legacyConfig)
@@ -91,23 +88,6 @@ export async function processConfigViaLegacyPlugins (projectRoot: string, legacy
     const configProcessArgs = ['--projectRoot', projectRoot, '--file', cwd]
     const CHILD_PROCESS_FILE_PATH = require.resolve('@packages/server/lib/plugins/child/require_async_child')
 
-    // use ts-node if they've got typescript installed
-    // this matches the 9.x behavior, which is what we want for
-    // processing legacy pluginsFile (we never supported `"type": "module") in 9.x.
-    if (hasTypeScriptInstalled(projectRoot)) {
-      const tsNodeLoader = `--require ${tsNode}`
-
-      if (!childOptions.env) {
-        childOptions.env = {}
-      }
-
-      if (childOptions.env.NODE_OPTIONS) {
-        childOptions.env.NODE_OPTIONS += ` ${tsNodeLoader}`
-      } else {
-        childOptions.env.NODE_OPTIONS = tsNodeLoader
-      }
-    }
-
     const childProcess = fork(CHILD_PROCESS_FILE_PATH, configProcessArgs, childOptions)
     const ipc = new LegacyPluginsIpc(childProcess)
 

packages/data-context/src/data/ProjectConfigIpc.ts

@@ -3,21 +3,17 @@ import { CypressError, getError } from '@packages/errors'
 import type { FullConfig, TestingType } from '@packages/types'
 import { ChildProcess, fork, ForkOptions } from 'child_process'
 import EventEmitter from 'events'
-import fs from 'fs-extra'
 import path from 'path'
 import inspector from 'inspector'
 import debugLib from 'debug'
-import { autoBindDebug, hasTypeScriptInstalled } from '../util'
+import { autoBindDebug } from '../util'
 import _ from 'lodash'
 
 const pkg = require('@packages/root')
 const debug = debugLib(`cypress:lifecycle:ProjectConfigIpc`)
 
 const CHILD_PROCESS_FILE_PATH = require.resolve('@packages/server/lib/plugins/child/require_async_child')
 
-const tsNodeEsm = require.resolve('ts-node/esm/transpile-only')
-const tsNode = require.resolve('@packages/server/lib/plugins/child/register_ts_node')
-
 export type IpcHandler = (ipc: ProjectConfigIpc) => void
 
 export interface SetupNodeEventsReply {
@@ -242,59 +238,6 @@ export class ProjectConfigIpc extends EventEmitter {
 
     debug('fork child process %o', { CHILD_PROCESS_FILE_PATH, configProcessArgs, childOptions: _.omit(childOptions, 'env') })
 
-    let isProjectUsingESModules = false
-
-    try {
-      const pkgJson = fs.readJsonSync(path.join(this.projectRoot, 'package.json'))
-
-      isProjectUsingESModules = pkgJson.type === 'module'
-    } catch (e) {
-      // project does not have `package.json` or it was not found
-      // reasonable to assume not using es modules
-    }
-
-    if (!childOptions.env) {
-      childOptions.env = {}
-    }
-
-    // If they've got TypeScript installed, we can use
-    // ts-node for CommonJS
-    // ts-node/esm for ESM
-    if (hasTypeScriptInstalled(this.projectRoot)) {
-      if (isProjectUsingESModules) {
-        // Use the ts-node/esm loader so they can use TypeScript with `"type": "module".
-        // The loader API is experimental and will change.
-        // The same can be said for the other alternative, esbuild, so this is the
-        // best option that leverages the existing modules we bundle in the binary.
-        // @see ts-node esm loader https://typestrong.org/ts-node/docs/usage/#node-flags-and-other-tools
-        // @see Node.js Loader API https://nodejs.org/api/esm.html#customizing-esm-specifier-resolution-algorithm
-        const tsNodeEsmLoader = `--experimental-specifier-resolution=node --loader ${tsNodeEsm}`
-
-        if (childOptions.env.NODE_OPTIONS) {
-          childOptions.env.NODE_OPTIONS += ` ${tsNodeEsmLoader}`
-        } else {
-          childOptions.env.NODE_OPTIONS = tsNodeEsmLoader
-        }
-      } else {
-        // Not using ES Modules (via "type": "module"),
-        // so we just register the standard ts-node module
-        // to handle TypeScript that is compiled to CommonJS.
-        // We do NOT use the `--loader` flag because we have some additional
-        // custom logic for ts-node when used with CommonJS that needs to be evaluated
-        // so we need to load and evaluate the hook first using the `--require` module API.
-        const tsNodeLoader = `--require ${tsNode}`
-
-        if (childOptions.env.NODE_OPTIONS) {
-          childOptions.env.NODE_OPTIONS += ` ${tsNodeLoader}`
-        } else {
-          childOptions.env.NODE_OPTIONS = tsNodeLoader
-        }
-      }
-    } else {
-      // Just use Node's built-in ESM support.
-      // TODO: Consider using userland `esbuild` with Node's --loader API to handle ESM.
-    }
-
     const proc = fork(CHILD_PROCESS_FILE_PATH, configProcessArgs, childOptions)
 
     return proc

packages/data-context/src/data/ProjectConfigManager.ts

@@ -260,17 +260,10 @@ export class ProjectConfigManager {
         this._eventsIpc.cleanupIpc()
       }
 
-      this._eventsIpc = new ProjectConfigIpc(
-        this.options.ctx.nodePath,
-        this.options.projectRoot,
-        this.configFilePath,
-        this.options.configFile,
-        (cypressError: CypressError, title?: string | undefined) => {
-          this._state = 'errored'
-          this.options.ctx.onError(cypressError, title)
-        },
-        this.options.ctx.onWarning,
-      )
+      this._eventsIpc = new ProjectConfigIpc(this.options.ctx.nodePath, this.options.projectRoot, this.configFilePath, this.options.configFile, (cypressError: CypressError, title?: string | undefined) => {
+        this._state = 'errored'
+        this.options.ctx.onError(cypressError, title)
+      }, this.options.ctx.onWarning)
 
       this._loadConfigPromise = this._eventsIpc.loadConfig()
     }

packages/data-context/src/util/index.ts

@@ -6,6 +6,5 @@ export * from './autoBindDebug'
 export * from './cached'
 export * from './config-file-updater'
 export * from './file'
-export * from './hasTypescript'
 export * from './pluginHandlers'
 export * from './urqlCacheKeys'

packages/launchpad/cypress/e2e/config-files-error-handling.cy.ts

@@ -173,7 +173,7 @@ describe('Launchpad: Error System Tests', () => {
     cy.contains('h1', cy.i18n.launchpadErrors.generic.configErrorTitle)
     cy.percySnapshot()
 
-    cy.get('[data-testid="error-code-frame"]').should('contain', 'cypress.config.ts:6:10')
+    cy.get('[data-testid="error-code-frame"]').should('contain', 'cypress.config.ts:6:9')
   })
 })
 

packages/launchpad/cypress/e2e/error-handling.cy.ts

@@ -80,7 +80,7 @@ describe('Error handling', () => {
       cy.contains('Choose a Browser').should('not.exist')
 
       cy.withCtx((ctx) => {
-        ctx.actions.file.writeFileInProject('cypress.config.ts', `
+        ctx.actions.file.writeFileInProject('cypress.config.js', `
           import { defineConfig } from 'cypress'
           import { defineConfig as viteConfig } from 'vite'
           export default defineConfig({

packages/server/lib/plugins/child/run_require_async_child.js

@@ -1,11 +1,12 @@
 require('graceful-fs').gracefulify(require('fs'))
 const stripAnsi = require('strip-ansi')
-const debugLib = require('debug')
+const debug = require('debug')(`cypress:lifecycle:child:run_require_async_child:${process.pid}`)
 const { pathToFileURL } = require('url')
+const tsNodeUtil = require('./ts_node')
 const util = require('../util')
 const { RunPlugins } = require('./run_plugins')
 
-const debug = debugLib(`cypress:lifecycle:child:run_require_async_child:${process.pid}`)
+let tsRegistered = false
 
 /**
  * Executes and returns the passed `file` (usually `configFile`) file in the ipc `loadConfig` event
@@ -21,6 +22,14 @@ function run (ipc, file, projectRoot) {
     throw new Error('Unexpected: projectRoot should be a string')
   }
 
+  if (!tsRegistered) {
+    debug('register typescript for required file')
+    tsNodeUtil.register(projectRoot, file)
+
+    // ensure typescript is only registered once
+    tsRegistered = true
+  }
+
   process.on('uncaughtException', (err) => {
     debug('uncaught exception:', util.serializeError(err))
     ipc.send('childProcess:unhandledError', util.serializeError(err))
@@ -83,9 +92,14 @@ function run (ipc, file, projectRoot) {
   // Config file loading of modules is tested within
   // system-tests/projects/config-cjs-and-esm/*
   const loadFile = async (file) => {
-    try {
-      debug('Loading file %s', file)
+    // 1. Try loading the configFile
+    // 2. Catch the "ERR_REQUIRE_ESM" error
+    // 3. Check if esbuild is installed
+    //   3a. Yes: Use bundleRequire
+    //   3b. No: Continue through to `await import(configFile)`
+    // 4. Use node's dynamic import to import the configFile
 
+    try {
       return require(file)
     } catch (err) {
       if (!err.stack.includes('[ERR_REQUIRE_ESM]') && !err.stack.includes('SyntaxError: Cannot use import statement outside a module')) {
@@ -96,16 +110,25 @@ function run (ipc, file, projectRoot) {
     debug('User is loading an ESM config file')
 
     try {
-      // We cannot replace the initial `require` with `await import` because
-      // Certain modules cannot be dynamically imported.
-      // pathToFileURL for windows interop: https://github.com/nodejs/node/issues/31710
-      const fileURL = pathToFileURL(file).href
+      debug('Trying to use esbuild to run their config file.')
+      // We prefer doing this because it supports TypeScript files
+      require.resolve('esbuild', { paths: [process.cwd()] })
 
-      debug(`importing esm file %s`, fileURL)
+      debug(`They have esbuild, so we'll load the configFile via bundleRequire`)
+      const { bundleRequire } = require('bundle-require')
 
-      return await import(fileURL)
+      return (await bundleRequire({ filepath: file })).mod
     } catch (err) {
-      debug('error loading file via native Node.js module loader %s', err.message)
+      if (err.stack.includes(`Cannot find module 'esbuild'`)) {
+        debug(`User doesn't have esbuild. Going to use native node imports.`)
+
+        // We cannot replace the initial `require` with `await import` because
+        // Certain modules cannot be dynamically imported.
+
+        // pathToFileURL for windows interop: https://github.com/nodejs/node/issues/31710
+        return await import(pathToFileURL(file).href)
+      }
+
       throw err
     }
   }

packages/server/test/unit/plugins/child/run_require_async_child_spec.js

@@ -1,6 +1,8 @@
 require('../../../spec_helper')
 
+const tsNodeUtil = require('../../../../lib/plugins/child/ts_node')
 const runRequireAsyncChild = require('../../../../lib/plugins/child/run_require_async_child')
+const resolve = require('../../../../lib/util/resolve')
 
 describe('lib/plugins/child/run_require_async_child', () => {
   beforeEach(function () {
@@ -15,6 +17,28 @@ describe('lib/plugins/child/run_require_async_child', () => {
     mockery.deregisterMock('@cypress/webpack-batteries-included-preprocessor')
   })
 
+  describe('typescript registration', () => {
+    beforeEach(() => {
+      sinon.stub(tsNodeUtil, 'register')
+      sinon.stub(resolve, 'typescript').returns('/path/to/typescript.js')
+    })
+
+    it('registers ts-node only once when typescript module found', function () {
+      runRequireAsyncChild(this.ipc, 'cypress.config.js', 'proj-root')
+      runRequireAsyncChild(this.ipc, 'cypress.config.js', 'proj-root')
+
+      expect(tsNodeUtil.register).to.be.calledWith(
+        'proj-root',
+        'cypress.config.js',
+      )
+
+      expect(tsNodeUtil.register).to.be.calledOnce
+    })
+
+    // FIXME: need to validate that TS is checked once when ts is not found as well
+    it.skip('checks for typescript only once if typescript module was not found')
+  })
+
   describe('errors', () => {
     beforeEach(function () {
       sinon.stub(process, 'on')

system-tests/projects/config-cjs-and-esm/config-with-cjs-tsconfig-es5/cypress/e2e/app.cy.js

@@ -0,0 +1,7 @@
+import { numberOne } from '../../src/foo'
+
+it('works', () => {
+  const number = 1
+
+  expect(numberOne).to.equal(number)
+})

system-tests/projects/config-cjs-and-esm/config-with-js-module/cypress/e2e/app.cy.js

@@ -0,0 +1,3 @@
+it('works', () => {
+  expect(true).to.be.true
+})

system-tests/projects/config-cjs-and-esm/config-with-js-module/package.json

@@ -1,4 +1,3 @@
 {
-  "type": "module",
-  "projectFixtureDirectory": "simple_passing"
+  "type": "module"
 }

system-tests/projects/config-cjs-and-esm/config-with-js-tsconfig-es2015/cypress/e2e/app.cy.js

@@ -0,0 +1,7 @@
+import { numberOne } from '../../src/foo'
+
+it('works', () => {
+  const number = 1
+
+  expect(numberOne).to.equal(number)
+})

system-tests/projects/config-cjs-and-esm/config-with-js-tsconfig-es2015/src/foo.ts

@@ -0,0 +1 @@
+export const numberOne = 1