NPM packages can declare named commands in the "scripts" section of their package.json. NPM scripts are a useful way to run repetitive tasks necessary for maintaining the package.

As an example, the ember.js package.json declares a start script to run a local web server, a test script to run the package’s test suite, and a build script to transpile, concatenate, and minify the package.

To execute the start script, run:

  $ npm start

To execute the test script, run:

  $ npm test

This will execute the pretest script before the test script.

To execute the build script, you would probably expect to run:

  $ npm build # womp womp

This will not behave like start or test.

NPM only supports a specific set of scripts and hooks, and build is not directly supported.

To execute the build script, run:

  $ npm run-script build

It is also important to note that a prebuild hook would not fire before the build script’s execution.