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npm-run-parallel

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Run npm tasks in parallel and exit when they are all done.

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Run npm tasks in parallel and exit when they are all done. ![Build Status](https://travis-ci.org/ianmcnally/npm-run-parallel.svg?branch=master) ## Installation Locally (recommended, especially with npm scripts): `npm install npm-run-parallel` Globally, as a CLI: `npm install -g npm-run-parallel` ## Usage From the command line, or an npm script: `npm-run-parallel <npm scripts>` So, if I want to run `npm install` and `npm test` in parallel (a contrived example, I know!): `npm-run-parallel install test` The process will complete when both `npm install` and `npm test` finish. _Note: you can run custom npm scripts, too. Just like you would `install` or `test` above._ ## Why? On a given project, there are likely some long or expensive npm scripts, like asset compilation or multi-directory dependency installs. It's faster to do these in parallel. A common way to run any shell command (which an npm script is) is the `&` operator, which creates a subprocess. This subprocess runs separately, so the original process can never tell how or when the subprocess ended. In a similar vein, the `|` operator can pipe the output of one command to another. This can feel like _streaming_, but passing the output of one npm script to another is both a hack and prone to erroring out. Some build tools, like gulp, accomplish parallel commands (a.k.a. tasks) with streaming libraries. The recent trend towards npm scripts from these walled-garden tools necessitated emulating that functionality. So `npm-run-parallel` all the tasks! #### Do I get colored terminal output from my tasks? Yes! It's awesome. I learned a lot about streams and stdout in the process of making this. ## Contributing See [CONTRIBUTING.md](https://github.com/ianmcnally/npm-run-parallel/blob/master/CONTRIBUTING.md) for the code of conduct. ### Local development - `npm run watch` - Compile source code, and watch for changes - `npm run lint` - Lints source code (eslint) - `npm run test:watch` - Run tests and watch for file changes #### Other commands - `npm run build` - Compiles source code (also used in `prepublish`) - `npm run test` - Run unit tests once - `npm run start --` - Emulates the cli interface (_note: pass it task arguments. Useful for manual testing._)