yarpm

A CLI tool to run npm scripts with either npm or yarn, depending on how it was started. Useful for setups where some team members use npm while others use yarn, especially when Windows and Unix-like systems are used across the team.

This tool is a helper to run scripts from package.json. Just substitute all npm or yarn calls with yarpm and you're good to go:

{
  "scripts": {
    "start": "yarpm run build",
    "build": "tsc index.ts"
  }
}

When running the start script with yarn start, the dependent build script will be spawned with yarn:

~/test$ yarn start
yarn start v0.21.3
$ yarpm run build
yarn run v0.21.3
$ tsc index.ts
Done in 1.92s.
Done in 2.27s.

Running the same script with npm start will result in the dependent build being run with npm:

~/test$ npm start

> test@0.0.1 start /home/me/test
> yarpm run build


> test@0.0.1 build /home/me/test
> tsc index.ts

What this tool is not

This tool is not meant to be an abstraction layer for calling npm or yarn. It will pass all arguments it receives unfiltered to the chosen package manager. So you could create the following package.json and pass the -s flag to yarpm to silence npm output:

{
  "scripts": {
    "start": "yarpm run -s build",
    "build": "tsc index.ts"
  }
}

This will work if you invoke the script with npm start. Running the script with yarn start will result in the following error:

yarn run v0.21.3
error No command specified.
....

This is due to the fact that yarn doesn't understand the -s option. This is up to you to write your scripts so that only commands and options available to both npm and yarn are used.

Installation

$ npm install yarpm --save-dev
# or
$ yarn add yarpm --dev

CLI Commands

The yarpm package provides 2 CLI commands:

• yarpm
• yarpm-yarn

The main command is yarpm.

yarpm

This command is an in-place substitute for places in package.json where npm or yarn is being used explicitly. It reads the npm_execpath environment variable to determine the path to the currently used package manager. This env var is only set when running yarpm as a script. If yarpm is used without being embedded in a script, it will always choose npm.

yarpm-yarn

This command can be used in places where you are not in control of how your script is being started, for example when using husky to run a script as a git hook. This script will always prefer yarn over npm unless yarn is not available. Only then will it fall back to npm.

Node API

The yarpm package provides a node API.

const yarpm = require('yarpm');
const promise = yarpm(argv, options);

• argv string[] -- The argument list to pass to npm/yarn.
• options object|undefined
  • options.npmPath string - The path to npm/yarn. Default is process.env.npm_execpath if set, npm otherwise.
  • options.env object - Sets the environment key-value pairs, replaces the default usage of process.env to spawn child process.
  • options.stdin stream.Readable|null -- A readable stream to send messages to stdin of child process. If this is null or undefined, ignores it. If this is process.stdin, inherits it. Otherwise, makes a pipe. Default is null. Set to process.stdin in order to send from stdin.
  • options.stdout stream.Writable|null -- A writable stream to receive messages from stdout of child process. If this is null or undefined, cannot send. If this is process.stdout, inherits it. Otherwise, makes a pipe. Default is null. Set to process.stdout in order to print to stdout.
  • options.stderr stream.Writable|null -- A writable stream to receive messages from stderr of child process. If this is null or undefined, cannot send. If this is process.stderr, inherits it. Otherwise, makes a pipe. Default is null. Set to process.stderr in order to print to stderr.

yarpm returns a promise will be resolved when the spawned process exits, regardless of the exit code. The promise will be rejected in case of an internal error inside of yarpm.

The promise is resolved with an object with the following 2 properties: spawnArgs and code. The spawnArgs property contains the array of parameters that were passed to spawn the sub-process. The code property is the exit code of the sub-process.

yarpm(['install']).then(result => {
  console.log(`${result.spawnArgs} -- ${result.code}`);
  // if executed as a package.json script via yarn: /usr/share/yarn/bin/yarn.js,install -- 0
});

Changelog

https://github.com/BendingBender/yarpm/blob/master/CHANGELOG.md

Contributing

Thank you for contributing!

Bug Reports or Feature Requests

Please use GitHub Issues.

License

MIT