Improve support for esbuild + esm with DD_BUILD_ESM env var

integration-tests/esbuild/build-and-run.esm-patched-const-banner.mjs

@@ -0,0 +1,30 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build({
+  ...commonConfig,
+  banner: {
+    js: `import { createRequire } from 'module';
+import { fileURLToPath  } from 'url';
+import { dirname } from 'path';
+const require = createRequire(import.meta.url);
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);`
+  }
+})
+
+const { status, stdout, stderr } = spawnSync('node', ['out.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build-and-run.esm-patched-global-banner.mjs

@@ -0,0 +1,30 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build({
+  ...commonConfig,
+  banner: {
+    js: `import { createRequire } from 'module';
+import { fileURLToPath  } from 'url';
+import { dirname } from 'path';
+globalThis.require ??= createRequire(import.meta.url);
+globalThis.__filename ??= fileURLToPath(import.meta.url);
+globalThis.__dirname ??= dirname(globalThis.__filename);`
+  }
+})
+
+const { status, stdout, stderr } = spawnSync('node', ['out.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build-and-run.esm-relying-in-extension.mjs

@@ -0,0 +1,23 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build({
+  ...commonConfig,
+  format: undefined
+})
+
+const { status, stdout, stderr } = spawnSync('node', ['out.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build-and-run.esm-relying-in-format.mjs

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import { renameSync } from 'fs'
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build({
+  ...commonConfig,
+  outfile: 'out.js'
+})
+
+// to force being executed as module
+renameSync('./out.js', './out.mjs')
+
+const { status, stdout, stderr } = spawnSync('node', ['out.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build-and-run.esm-relying-in-out-extension.mjs

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import commonConfig from './build.esm.common-config.js'
+
+// output => basic-test.mjs
+await esbuild.build({
+  ...commonConfig,
+  outfile: undefined,
+  format: undefined,
+  outdir: './',
+  outExtension: { '.js': '.mjs' }
+})
+
+const { status, stdout, stderr } = spawnSync('node', ['basic-test.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build-and-run.esm-unrelated-js-banner.mjs

@@ -0,0 +1,25 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+
+import esbuild from 'esbuild'
+import { spawnSync } from 'child_process'
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build({
+  ...commonConfig,
+  banner: {
+    js: '/* js test */'
+  }
+})
+
+const { status, stdout, stderr } = spawnSync('node', ['out.mjs'])
+if (stdout.length) {
+  console.log(stdout.toString())
+}
+if (stderr.length) {
+  console.error(stderr.toString())
+}
+if (status) {
+  throw new Error('generated script failed to run')
+}
+console.log('ok')

integration-tests/esbuild/build.esm.common-config.js

@@ -0,0 +1,21 @@
+const ddPlugin = require('../../esbuild')
+module.exports = {
+  format: 'esm',
+  entryPoints: ['basic-test.js'],
+  bundle: true,
+  outfile: 'out.mjs',
+  plugins: [ddPlugin],
+  platform: 'node',
+  target: ['node18'],
+  external: [
+    // dead code paths introduced by knex
+    'pg',
+    'mysql2',
+    'better-sqlite3',
+    'sqlite3',
+    'mysql',
+    'oracledb',
+    'pg-query-stream',
+    'tedious'
+  ]
+}

integration-tests/esbuild/build.esm.mjs

@@ -0,0 +1,7 @@
+#!/usr/bin/env node
+
+import esbuild from 'esbuild'
+
+import commonConfig from './build.esm.common-config.js'
+
+await esbuild.build(commonConfig)

integration-tests/esbuild/index.spec.js

@@ -7,6 +7,7 @@
 const chproc = require('child_process')
 const path = require('path')
 const fs = require('fs')
+const { assert } = require('chai')
 
 const TEST_DIR = path.join(__dirname, '.')
 process.chdir(TEST_DIR)
@@ -75,5 +76,93 @@ esbuildVersions.forEach((version) => {
         timeout: 1000 * 30
       })
     })
+
+    describe('ESM', () => {
+      afterEach(() => {
+        fs.rmSync('./out.mjs', { force: true })
+        fs.rmSync('./out.js', { force: true })
+        fs.rmSync('./basic-test.mjs', { force: true })
+      })
+
+      it('works', () => {
+        console.log('npm run build:esm')
+        chproc.execSync('npm run build:esm')
+        console.log('npm run built:esm')
+        chproc.execSync('npm run built:esm', {
+          timeout: 1000 * 30
+        })
+      })
+
+      it('should not override existing js banner', () => {
+        const command = 'node ./build-and-run.esm-unrelated-js-banner.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+
+        const builtFile = fs.readFileSync('./out.mjs').toString()
+        assert.include(builtFile, '/* js test */')
+      })
+
+      it('should contain the definitions when esm is inferred from outfile', () => {
+        const command = 'node ./build-and-run.esm-relying-in-extension.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+
+        const builtFile = fs.readFileSync('./out.mjs').toString()
+        assert.include(builtFile, 'globalThis.__filename ??= $dd_fileURLToPath(import.meta.url);')
+      })
+
+      it('should contain the definitions when esm is inferred from format', () => {
+        const command = 'node ./build-and-run.esm-relying-in-format.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+
+        const builtFile = fs.readFileSync('./out.mjs').toString()
+        assert.include(builtFile, 'globalThis.__filename ??= $dd_fileURLToPath(import.meta.url);')
+      })
+
+      it('should contain the definitions when format is inferred from out extension', () => {
+        const command = 'node ./build-and-run.esm-relying-in-out-extension.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+
+        const builtFile = fs.readFileSync('./basic-test.mjs').toString()
+        assert.include(builtFile, 'globalThis.__filename ??= $dd_fileURLToPath(import.meta.url);')
+      })
+
+      it('should not contain the definitions when no esm is specified', () => {
+        const command = 'node ./build.js'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+
+        const builtFile = fs.readFileSync('./out.js').toString()
+        assert.notInclude(builtFile, 'globalThis.__filename ??= $dd_fileURLToPath(import.meta.url);')
+      })
+
+      it('should not crash when it is already patched using global', () => {
+        const command = 'node ./build-and-run.esm-patched-global-banner.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+      })
+
+      it('should not crash when it is already patched using const', () => {
+        const command = 'node ./build-and-run.esm-patched-const-banner.mjs'
+        console.log(command)
+        chproc.execSync(command, {
+          timeout: 1000 * 30
+        })
+      })
+    })
   })
 })

integration-tests/esbuild/package.json

@@ -6,7 +6,9 @@
   "main": "app.js",
   "scripts": {
     "build": "DD_TRACE_DEBUG=true node ./build.js",
+    "build:esm": "DD_TRACE_DEBUG=true node ./build.esm.mjs",
     "built": "DD_TRACE_DEBUG=true node ./out.js",
+    "built:esm": "DD_TRACE_DEBUG=true node ./out.mjs",
     "raw": "DD_TRACE_DEBUG=true node ./app.js",
     "link": "pushd ../.. && yarn link && popd && yarn link dd-trace",
     "request": "curl http://localhost:3000 | jq"

packages/datadog-esbuild/index.js

@@ -53,8 +53,30 @@ for (const pkg of INSTRUMENTED) {
 
 module.exports.name = 'datadog-esbuild'
 
+function isESMBuild (build) {
+  // check toLowerCase? to be safe if unexpected object is there instead of a string
+  const format = build.initialOptions.format?.toLowerCase?.()
+  const outputFile = build.initialOptions.outfile?.toLowerCase?.()
+  const outExtension = build.initialOptions.outExtension?.['.js']
+  return format === 'esm' || outputFile?.endsWith('.mjs') || outExtension === '.mjs'
+}
+
 module.exports.setup = function (build) {
   const externalModules = new Set(build.initialOptions.external || [])
+  if (isESMBuild(build)) {
+    build.initialOptions.banner ??= {}
+    build.initialOptions.banner.js ??= ''
+    if (!build.initialOptions.banner.js.includes('import { createRequire as $dd_createRequire } from \'module\'')) {
+      build.initialOptions.banner.js = `import { createRequire as $dd_createRequire } from 'module';
+import { fileURLToPath as $dd_fileURLToPath } from 'url';
+import { dirname as $dd_dirname } from 'path';
+globalThis.require ??= $dd_createRequire(import.meta.url);
+globalThis.__filename ??= $dd_fileURLToPath(import.meta.url);
+globalThis.__dirname ??= $dd_dirname(globalThis.__filename);
+${build.initialOptions.banner.js}`
+    }
+  }
+
   build.onResolve({ filter: /.*/ }, args => {
     if (externalModules.has(args.path)) {
       // Internal Node.js packages will still be instrumented via require()