grunt npm dedupe

grunt-npm-dedupe.js

var spawnSync = require('spawn-sync');
var NODE_ENV = process.env.NODE_ENV;
var production = (NODE_ENV === 'production');

/**
 * `npm dedupe` in cwd
 * @return {undefined}
 */
var dedupe = function() {
    var result;
    result = spawnSync('npm', ['dedupe']); // 3rd arg, {cwd: ...}
    process.stdout.write(result.stdout);
    process.stderr.write(result.stderr);
    if (result.status !== 0) {
        process.exit(result.status);
    }
};

module.exports = function(grunt) {
    grunt.registerTask('dedupe', 'dedupe', function() {
        if (!development) {
            dedupe();
        } else {
            console.warn("notice: your browser dir will not be `npm dedupe`d in modes !== 'production'");
        }
    });
};

use before browserifying or webpacking prd code, pre npm3.0 (which promises ultra de-duping greatness!)