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npmyarnpkgnpm-scripts

Is there a way to get the name of the npm script passed to the command specified by that script?

With npm or yarn, is it possible for the script specified by an npm script to know the name of the npm script itself? For example:

"scripts": {
  "foo": "echo Original command: $0",
  "bar": "echo Original command: $0"
}

I'd like the result of those two scripts to be something like:

Original command: yarn run foo
Original command: yarn run bar

But all I actually get is: Original command: /bin/sh.

And in case it makes a difference, it's just the name of the script I need, not the yarn run part, so output like Original command: foo would be fine.

Solution

  • NPM adds the npm_lifecycle_event environment variable. It's similar to package.json vars.

    *Nix (Linux, macOS, ... )

    On *nix platforms npm utilizes sh as the default shell for running npm scripts, therefore your scripts can be defined as:

    "scripts": {
  "foo": "echo The script run was: $npm_lifecycle_event",
  "bar": "echo The script run was: $npm_lifecycle_event"
}

    Note: The dollar prefix $ to reference the variable.

    Windows:

    On Windows npm utilizes cmd.exe as the default shell for running npm scripts, therefore your scripts can be defined as:

    "scripts": {
  "foo": "echo The script run was: %npm_lifecycle_event%",
  "bar": "echo The script run was: %npm_lifecycle_event%"
}

    Note: The leading and trailing percentage sign % used to reference the variable.

    Cross-platform (Linux, macOS, Windows, ... )

    For cross-platform you can either:

    1. Utilize cross-var to enable a single syntax, i.e. using the dollar sign prefix $ as per the *nix syntax.

    2. Or, utilize the node.js command line option -p to evaluate and print the result of the following inline JavaScript:

      "scripts": {
  "foo": "node -e \"console.log('The script run was:', process.env.npm_lifecycle_event)\"",
  "bar": "node -e \"console.log('The script run was:', process.env.npm_lifecycle_event)\""
}

      Note In this example we:

      • Access the npm_lifecycle_event environment variable using the node.js process.env property.
      • Utilize console.log (instead of echo) to print the result to stdout