puppeteer/typescript-if-required.js
Jack Franklin 20c22ad9ad
chore: fix installing from GitHub URL (#5669)
The change to the install script to require TypeScript works fine when
installing from npm (because on npm the `lib` directory with the
compiled code already exists) but doesn't if you install from a GitHub
URL. By default it seems npm uses the `files` list when you install from
GitHub which means it's missing a bunch of files that we need to
compile.

Additionally by default when installing from a GitHub URL npm doesn't
install the dependencies which is an issue for us when we need to
compile TypeScript.

The fix is to create a `prepare` script that runs TypeScript if
required. From the npm docs [1]:

> `prepare`: Run both BEFORE the package is packed and published, on
> local npm install without any arguments, and when installing git
> dependencies

And from the npm docs on install [2], it confirms that if a package has
a `prepare` script it is run when installing from GitHub:

> As with regular git dependencies, dependencies and devDependencies
> will be installed if the package has a prepare script, before the
> package is done installing.

Despite having the `prepare` script we still need the TypeScript check
in `install.js` to satisfy the 3rd scenario below where we need to force
a compile:

* If I'm a user installing `puppeteer@X` from npm, the module is
published with the `lib/` directory of compiled code, so I'm set.
* If I'm a user installing Puppeteer from GitHub, the `prepare` script
will run TypeScript for me so I'm set.
* If I'm a developer working on Puppeteer, the `prepare` script also
runs but _after_ `npm install` which means `install.js` fails as it
requires `./lib/helper.js`. So in `install.js` we call
`compileTypeScriptIfRequired` to catch this case.

[1]: https://docs.npmjs.com/misc/scripts
[2]: https://docs.npmjs.com/cli/install

Co-authored-by: Mathias Bynens <mathias@qiwi.be>

Fixes #5660.
2020-04-17 11:29:40 +02:00

60 lines
2.0 KiB
JavaScript

/**
* 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.
*/
const child_process = require('child_process');
const path = require('path');
const fs = require('fs');
const {promisify} = require('util');
const exec = promisify(child_process.exec);
const fsAccess = promisify(fs.access);
const fileExists = async filePath => fsAccess(filePath).then(() => true).catch(() => false);
/*
* Now Puppeteer is built with TypeScript, we need to ensure that
* locally we have the generated output before trying to install.
*
* For users installing puppeteer this is fine, they will have the
* generated lib/ directory as we ship it when we publish to npm.
*
* However, if you're cloning the repo to contribute, you won't have the
* generated lib/ directory so this script checks if we need to run
* TypeScript first to ensure the output exists and is in the right
* place.
*/
async function compileTypeScript() {
return exec('npm run tsc').catch(err => {
console.error('Error running TypeScript', err);
process.exit(1);
});
}
async function compileTypeScriptIfRequired() {
const libPath = path.join(__dirname, 'lib');
const libExists = await fileExists(libPath);
if (libExists) return;
console.log('Puppeteer:', 'Compiling TypeScript...');
await compileTypeScript();
}
// It's being run as node typescript-if-required.js, not require('..')
if (require.main === module)
compileTypeScriptIfRequired();
module.exports = compileTypeScriptIfRequired;