Check your project's requirements against your current Node environment.
Ahem looks for a package.json in the current working directory, looks for an node property inside the engines property, and compares the two using semver. If the project's requirements are satisfied, it exits cleanly. Otherwise it exits with an error code of 1.
It's quite aggressive - if it can't find an engines / node entry, it'll exit with an error. The reason being is that if you need to be using it, it should be quite strict.
Originally intended to make running old spine projects less painful, hence the name (thanks marten).
Add it to your project by running:
npm install --save-dev ahem
You could also install it globally by running:
npm install -g ahem
...but you're probably better off not doing that. This should only ever be a crutch for legacy projects.
In your project's package.json, set the version of Node it supports via the engines property:
"engines": {
"node": "0.12.7"
}
Then run it before your build processes start, through the bin available at ./node_modules/bin/ahem. Or require it into your Javascript and pass a directory as an argument:
var ahem = require('ahem');
ahem(process.cwd());
In a ruby build script:
system('./node_modules/.bin/ahem') or exit(1)
# Carry on building stuff...
In an NPM packages.json:
"scripts": {
"start": "ahem && haw serve",
}
This errors explosively - if you have a better way, let me know!