chore: move index.js into src and TS-ify (#6049)

It was causing some infra issues when trying to migrate tests to
TypeScript (that's WIP in another branch that I'll have up soon). It's
unusual to have the entire src in TS except for the main file, which
then reaches into the compiled `lib` directory for the files it needs.

Much better is to move the entry point into TypeScript itself and update
the `main` entry in our `package.json` to point to the compiled output.

This also has the advantange of hooking up all the TS type defs that we
are shipping and will make that process easier too, along with making it
easier to port our tests to TypeScript.

install.js

@@ -41,7 +41,7 @@ async function download() {
     process.env.PUPPETEER_DOWNLOAD_HOST ||
     process.env.npm_config_puppeteer_download_host ||
     process.env.npm_package_config_puppeteer_download_host;
-  const puppeteer = require('./index');
+  const puppeteer = require('.');
   const product =
     process.env.PUPPETEER_PRODUCT ||
     process.env.npm_config_puppeteer_product ||

package.json

@@ -2,7 +2,7 @@
   "name": "puppeteer",
   "version": "4.0.0-post",
   "description": "A high-level API to control headless Chrome over the DevTools Protocol",
-  "main": "index.js",
+  "main": "lib/index.js",
   "repository": "github:puppeteer/puppeteer",
   "engines": {
     "node": ">=10.18.1"

src/index.ts

@@ -1,5 +1,5 @@
 /**
- * Copyright 2020 Google Inc. All rights reserved.
+ * Copyright 2017 Google Inc. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,59 +14,21 @@
  * limitations under the License.
  */
 
-// api.ts has to use module.exports as it's also consumed by DocLint which runs
-// on Node.
-// eslint-disable-next-line @typescript-eslint/no-var-requires
-const api = require('./api');
+import { initializePuppeteer } from './initialize';
+import * as path from 'path';
 
-import { helper } from './common/helper';
-import { Page } from './common/Page';
-import { Puppeteer } from './common/Puppeteer';
+const puppeteer = initializePuppeteer({
+  packageJson: require(path.join(__dirname, '..', 'package.json')),
+  rootDirectory: path.join(__dirname, '..'),
+});
 
-interface InitOptions {
-  packageJson: {
-    puppeteer: {
-      chromium_revision: string;
-      firefox_revision: string;
-    };
-    name: string;
-  };
-  rootDirectory: string;
-}
-
-export const initializePuppeteer = (options: InitOptions): Puppeteer => {
-  const { packageJson, rootDirectory } = options;
-
-  for (const className in api) {
-    if (typeof api[className] === 'function')
-      helper.installAsyncStackHooks(api[className]);
-  }
-
-  // Expose alias for deprecated method.
-  // @ts-expect-error emulateMedia does not exist error
-  Page.prototype.emulateMedia = Page.prototype.emulateMediaType;
-
-  let preferredRevision = packageJson.puppeteer.chromium_revision;
-  const isPuppeteerCore = packageJson.name === 'puppeteer-core';
-  // puppeteer-core ignores environment variables
-  const product = isPuppeteerCore
-    ? undefined
-    : process.env.PUPPETEER_PRODUCT ||
-      process.env.npm_config_puppeteer_product ||
-      process.env.npm_package_config_puppeteer_product;
-  if (!isPuppeteerCore && product === 'firefox')
-    preferredRevision = packageJson.puppeteer.firefox_revision;
-
-  const puppeteer = new Puppeteer(
-    rootDirectory,
-    preferredRevision,
-    isPuppeteerCore,
-    product
-  );
-
-  // The introspection in `Helper.installAsyncStackHooks` references `Puppeteer._launcher`
-  // before the Puppeteer ctor is called, such that an invalid Launcher is selected at import,
-  // so we reset it.
-  puppeteer._lazyLauncher = undefined;
-  return puppeteer;
-};
+/*
+ * Has to be CJS here rather than ESM such that the output file ends with
+ * module.exports = puppeteer.
+ *
+ * If this was export default puppeteer the output would be:
+ * exports.default = puppeteer
+ * And therefore consuming via require('puppeteer') would break / require the user
+ * to access require('puppeteer').default;
+ */
+module.exports = puppeteer;

src/initialize.ts

@@ -0,0 +1,72 @@
+/**
+ * Copyright 2020 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// api.ts has to use module.exports as it's also consumed by DocLint which runs
+// on Node.
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const api = require('./api');
+
+import { helper } from './common/helper';
+import { Page } from './common/Page';
+import { Puppeteer } from './common/Puppeteer';
+
+interface InitOptions {
+  packageJson: {
+    puppeteer: {
+      chromium_revision: string;
+      firefox_revision: string;
+    };
+    name: string;
+  };
+  rootDirectory: string;
+}
+
+export const initializePuppeteer = (options: InitOptions): Puppeteer => {
+  const { packageJson, rootDirectory } = options;
+
+  for (const className in api) {
+    if (typeof api[className] === 'function')
+      helper.installAsyncStackHooks(api[className]);
+  }
+
+  // Expose alias for deprecated method.
+  // @ts-expect-error emulateMedia does not exist error
+  Page.prototype.emulateMedia = Page.prototype.emulateMediaType;
+
+  let preferredRevision = packageJson.puppeteer.chromium_revision;
+  const isPuppeteerCore = packageJson.name === 'puppeteer-core';
+  // puppeteer-core ignores environment variables
+  const product = isPuppeteerCore
+    ? undefined
+    : process.env.PUPPETEER_PRODUCT ||
+      process.env.npm_config_puppeteer_product ||
+      process.env.npm_package_config_puppeteer_product;
+  if (!isPuppeteerCore && product === 'firefox')
+    preferredRevision = packageJson.puppeteer.firefox_revision;
+
+  const puppeteer = new Puppeteer(
+    rootDirectory,
+    preferredRevision,
+    isPuppeteerCore,
+    product
+  );
+
+  // The introspection in `Helper.installAsyncStackHooks` references `Puppeteer._launcher`
+  // before the Puppeteer ctor is called, such that an invalid Launcher is selected at import,
+  // so we reset it.
+  puppeteer._lazyLauncher = undefined;
+  return puppeteer;
+};