@delucis/if-env

Run an npm script if an environment variable matches a pattern

This is a fork of Eric Clemmons’s if-env. It allows you to match environment variables using wildcards (*) rather than using simple string equality. See Sindre Sorhus’s matcher for details about how the matching works.

Installation

npm install --save @delucis/if-env

Usage

This package installs if-env, a script which lets you easily match environment variable values against a pattern using wildcards. It also includes if-env-cs, which is case sensitive.

If you want to to run an NPM script conditionally, depending on the value of an environment variable, you can use if-env in your package.json. In this example, we only want to run our test script when the SOME_VAR variable starts with new:

"scripts": {
  "test": "if-env SOME_VAR=new* && npm run test-suite"
}

Multiple conditions

If you want several conditions to be met you can pass them all to if-env:

"scripts": {
  "yay": "if-env VAR1=woo* VAR2=*hoo && echo yay"
}

If you want to run a script if either one or another condition is met, you can use the || operator:

"scripts": {
  "moo": "if-env ANIMAL=cow || if-env ANIMAL=bull* && echo moo"
}

If you want to do different things depending on the value of a variable, you can also use the || operator:

"scripts": {
  "joy": "if-env MOOD=happy && echo 😄 || echo 😭"
}

Negating conditions

If you want to do something if a variable does not match a pattern, you have two options. Note the single quotes in the first example; they escape ! for your shell.

"scripts": {
  "ifenv": "if-env MOOD='!happy' && echo 😭",
  "shell": "if-env MOOD=happy || echo 😭"
}

Escaping characters

If you need to have spaces in your pattern, make sure you wrap it in quotes:

"scripts": {
  "spacious": "if-env SENTENCE='I want * spaces.' && echo You get spaces!"
}

Case sensitivity

if-env is case insensitive, which means if-env VAR=foo will match both foo and FOO. If you need to test a variable and case is important, use the if-env-cs command:

"scripts": {
  "case": "if-env-cs WORD=lower && echo nice! || echo STOP SHOUTING!"
}