package-merge

Intelligently merge package.json files.

This is pretty much built for yeoman. It attempts to combine two separate package.json files into one, respecting as much existing content as possible including already existing dependencies and package.json formatting.

var merge = require('package-merge');
var dst = fs.readFileSync('package.a.json');
var src = fs.readFileSync('package.b.json');

// Create a new `package.json`
console.log(merge(dst, src));

It allows you to do things like define scripts or dependencies that you would like to include as part of a larger project.

Merging:

{
    "name": "my-package",
    "dependencies": {
        "babel": "^5.2.2",
        "lodash": "^3.2.5"
    }
}

{
    "dependencies": {
        "babel": "^5.4.1",
        "eslint": "^0.22.1"
    }
}

results in:

{
    "name": "my-package",
    "dependencies": {
        "babel": "^5.4.1",
        "lodash": "^3.2.5",
        "eslint": "^0.22.1"
    }
}