feat(puppeteer): export esm modules in package.json (#7964)

* feat(puppeteer): export esm modules in package.json

Signed-off-by: Randolf Jung <jrandolf@chromium.org>

Co-authored-by: Alex Rudenko <OrKoN@users.noreply.github.com>
Co-authored-by: Randolf Jung <jrandolf@chromium.org>

.gitignore

@@ -19,7 +19,7 @@ yarn.lock
 test/coverage.json
 temp/
 new-docs/
-puppeteer.tgz
+puppeteer*.tgz
 docs-api-json/
 docs-dist/
 website/docs

compat/README.md

@@ -0,0 +1,16 @@
+# Compatibility layer
+
+This directory provides an additional compatibility layer between ES modules and CommonJS.
+
+## Why?
+
+Both `./cjs/compat.ts` and `./esm/compat.ts` are written as ES modules, but `./cjs/compat.ts` can additionally use NodeJS CommonJS globals such as `__dirname` and `require` while these are disabled in ES module mode. For more information, see [Differences between ES modules and CommonJS](https://nodejs.org/api/esm.html#differences-between-es-modules-and-commonjs).
+
+## Adding exports
+
+In order to add exports, two things need to be done:
+
+- The exports must be declared in `src/compat.ts`.
+- The exports must be realized in `./cjs/compat.ts` and `./esm/compat.ts`.
+
+In the event `compat.ts` becomes too large, you can place declarations in another file. Just make sure `./cjs`, `./esm`, and `src` have the same structure.

compat/cjs/compat.ts

@@ -0,0 +1,3 @@
+import { dirname } from 'path';
+
+export const puppeteerDirname = dirname(dirname(dirname(__dirname)));

compat/cjs/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "../../lib/cjs/puppeteer",
+    "module": "CommonJS"
+  },
+  "references": [
+    { "path": "../../vendor/tsconfig.cjs.json"}
+  ]
+}

compat/esm/compat.ts

@@ -0,0 +1,6 @@
+import { dirname } from 'path';
+import { fileURLToPath } from 'url';
+
+export const puppeteerDirname = dirname(
+  dirname(dirname(dirname(fileURLToPath(import.meta.url))))
+);

compat/esm/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "../../lib/esm/puppeteer",
+    "module": "esnext"
+  },
+  "references": [{ "path": "../../vendor/tsconfig.esm.json" }]
+}

package.json

@@ -2,7 +2,12 @@
   "name": "puppeteer",
   "version": "13.2.0-post",
   "description": "A high-level API to control headless Chrome over the DevTools Protocol",
+  "type": "commonjs",
   "main": "./cjs-entry.js",
+  "exports": {
+    "import": "./lib/esm/puppeteer/node.js",
+    "require": "./cjs-entry.js"
+  },
   "types": "lib/types.d.ts",
   "repository": "github:puppeteer/puppeteer",
   "engines": {
@@ -29,15 +34,18 @@
     "lint": "npm run eslint && npm run build && npm run doc && npm run markdownlint",
     "doc": "node utils/doclint/cli.js",
     "clean-lib": "rimraf lib",
-    "build": "npm run tsc && npm run generate-d-ts",
+    "build": "npm run tsc && npm run generate-d-ts && npm run generate-pkg-json",
-    "tsc": "npm run clean-lib && tsc --version && npm run tsc-cjs && npm run tsc-esm",
+    "tsc": "npm run clean-lib && tsc --version && (npm run tsc-cjs & npm run tsc-esm) && (npm run tsc-compat-cjs & npm run tsc-compat-esm)",
     "tsc-cjs": "tsc -b src/tsconfig.cjs.json",
     "tsc-esm": "tsc -b src/tsconfig.esm.json",
+    "tsc-compat-cjs": "tsc -b compat/cjs/tsconfig.json",
+    "tsc-compat-esm": "tsc -b compat/esm/tsconfig.json",
     "apply-next-version": "node utils/apply_next_version.js",
     "test-install": "scripts/test-install.sh",
     "clean-docs": "rimraf website/docs && rimraf docs-api-json",
     "generate-d-ts": "npm run clean-docs && api-extractor run --local --verbose",
     "generate-docs": "npm run generate-d-ts && api-documenter markdown -i docs-api-json -o website/docs && node utils/remove-tag.js",
+    "generate-pkg-json": "echo '{\"type\": \"module\"}' > lib/esm/package.json",
     "ensure-correct-devtools-protocol-revision": "ts-node -s scripts/ensure-correct-devtools-protocol-package",
     "ensure-pinned-deps": "ts-node -s scripts/ensure-pinned-deps",
     "test-types-file": "ts-node -s scripts/test-ts-definition-files.ts",
@@ -50,6 +58,7 @@
     "lib/**/*.d.ts.map",
     "lib/**/*.js",
     "lib/**/*.js.map",
+    "lib/**/package.json",
     "install.js",
     "typescript-if-required.js",
     "cjs-entry.js",

scripts/test-install.sh

@@ -16,6 +16,26 @@ npm install --loglevel silent "${tarball}"
 node --eval="require('puppeteer')"
 ls $TMPDIR/node_modules/puppeteer/.local-chromium/
 
+# Testing ES module features
+TMPDIR="$(mktemp -d)"
+cd $TMPDIR
+echo '{"type":"module"}' >>$TMPDIR/package.json
+npm install --loglevel silent "${tarball}"
+node --input-type="module" --eval="import puppeteer from 'puppeteer'"
+ls $TMPDIR/node_modules/puppeteer/.local-chromium/
+
+node --input-type="module" --eval="
+import puppeteer from 'puppeteer';
+
+(async () => {
+  const browser = await puppeteer.launch();
+  const page = await browser.newPage();
+  await page.goto('http://example.com');
+  await page.screenshot({ path: 'example.png' });
+  await browser.close();
+})();
+"
+
 # Again for Firefox
 TMPDIR="$(mktemp -d)"
 cd $TMPDIR
@@ -39,3 +59,9 @@ cd $TMPDIR
 npm install --loglevel silent "${tarball}"
 node --eval="require('puppeteer-core')"
 
+# Testing ES module features
+TMPDIR="$(mktemp -d)"
+cd $TMPDIR
+echo '{"type":"module"}' >>$TMPDIR/package.json
+npm install --loglevel silent "${tarball}"
+node --input-type="module" --eval="import puppeteer from 'puppeteer-core'"

src/common/Debug.ts

@@ -55,7 +55,9 @@ import { isNode } from '../environment.js';
 export const debug = (prefix: string): ((...args: unknown[]) => void) => {
   if (isNode) {
     // eslint-disable-next-line @typescript-eslint/no-var-requires
-    return require('debug')(prefix);
+    return async (...logArgs: unknown[]) => {
+      (await import('debug')).default(prefix)(logArgs);
+    };
   }
 
   return (...logArgs: unknown[]): void => {

src/compat.ts

@@ -0,0 +1,3 @@
+declare const puppeteerDirname: string;
+
+export { puppeteerDirname };

src/initialize-node.ts

@@ -18,9 +18,10 @@ import { PuppeteerNode } from './node/Puppeteer.js';
 import { PUPPETEER_REVISIONS } from './revisions.js';
 import pkgDir from 'pkg-dir';
 import { Product } from './common/Product.js';
+import { puppeteerDirname } from './compat.js';
 
 export const initializePuppeteerNode = (packageName: string): PuppeteerNode => {
-  const puppeteerRootDirectory = pkgDir.sync(__dirname);
+  const puppeteerRootDirectory = pkgDir.sync(puppeteerDirname);
 
   let preferredRevision = PUPPETEER_REVISIONS.chromium;
   const isPuppeteerCore = packageName === 'puppeteer-core';

src/node/BrowserFetcher.ts

@@ -34,6 +34,8 @@ import createHttpsProxyAgent, {
 } from 'https-proxy-agent';
 import { getProxyForUrl } from 'proxy-from-env';
 import { assert } from '../common/assert.js';
+import tar from 'tar-fs';
+import bzip from 'unbzip2-stream';
 
 const debugFetcher = debug('puppeteer:fetcher');
 
@@ -499,10 +501,6 @@ function install(archivePath: string, folderPath: string): Promise<unknown> {
  * @internal
  */
 function extractTar(tarPath: string, folderPath: string): Promise<unknown> {
-  // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const tar = require('tar-fs');
-  // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const bzip = require('unbzip2-stream');
   return new Promise((fulfill, reject) => {
     const tarStream = tar.extract(folderPath);
     tarStream.on('error', reject);

src/node/NodeWebSocketTransport.ts

@@ -15,18 +15,26 @@
  */
 import { ConnectionTransport } from '../common/ConnectionTransport.js';
 import NodeWebSocket from 'ws';
+import { readFileSync } from 'fs';
+import { join } from 'path';
+import { puppeteerDirname } from '../compat.js';
+
+// We parse rather than import for ES module compatibility.
+const version = JSON.parse(
+  readFileSync(join(puppeteerDirname, 'package.json'), {
+    encoding: 'utf8',
+  })
+).version;
 
 export class NodeWebSocketTransport implements ConnectionTransport {
   static create(url: string): Promise<NodeWebSocketTransport> {
-    // eslint-disable-next-line @typescript-eslint/no-var-requires
-    const pkg = require('../../../../package.json');
     return new Promise((resolve, reject) => {
       const ws = new NodeWebSocket(url, [], {
         followRedirects: true,
         perMessageDeflate: false,
         maxPayload: 256 * 1024 * 1024, // 256Mb
         headers: {
-          'User-Agent': `Puppeteer ${pkg.version}`,
+          'User-Agent': `Puppeteer ${version}`,
         },
       });
 

tsconfig.json

@@ -12,5 +12,5 @@
      */
     "module": "esnext"
   },
-  "include": ["src"]
+  "include": ["src"],
 }

utils/prepare_puppeteer_core.js

@@ -21,7 +21,9 @@ const path = require('path');
 const packagePath = path.join(__dirname, '..', 'package.json');
 const json = require(packagePath);
 
-json.name = 'puppeteer-core';
 delete json.scripts.install;
+
+json.name = 'puppeteer-core';
 json.main = './cjs-entry-core.js';
+json.exports.import = './lib/esm/puppeteer/node-puppeteer-core.js';
 fs.writeFileSync(packagePath, JSON.stringify(json, null, '  '));