TIL that env var values in "scripts" in package.json files are respected by npm.

README.md

npm-scripts-envvar

It works!

$ npm test
npm info it worked if it ends with ok
npm info using [email protected]
npm info using [email protected]
npm info pretest [email protected]
npm info test [email protected]

> [email protected] test /Users/charlie/Experimental/npm-scripts-envvar
> THIS_WORKS=test node index.js

process.env.THIS_WORKS=test
npm info posttest [email protected]
npm info ok 

index.js

console.log('process.env.THIS_WORKS=%s', process.env.THIS_WORKS);

package.json

{
  "name": "npm-scripts-envvar",
  "version": "1.0.0",
  "description": "Test to see if envvars work in \"npm scripts\"",
  "main": "index.js",
  "scripts": {
    "test": "THIS_WORKS=test node index.js"
  },
  "author": "Charlie Robbins <[email protected]>",
  "license": "MIT"
}