Plugin to address browserify/browserify#1505

offsetify.js

var through = require('through2');

var setup = function(b, cb) {
    b.on('reset', cb);
    cb();
};

module.exports = function offsetify(b, externalBundles) {
    setup(b, function() {
        b.pipeline.get('sort').push(through.obj(function(row, enc, next) {
            var offset = externalBundles.reduce(function(sum, eb) {
              return sum + eb._offsetifyOffset;
            }, 0);
            row.index += offset;

            for (var key in row.indexDeps) {
                if ({}.hasOwnProperty.call(row.indexDeps, key)) {
                    row.indexDeps[key] += offset;
                }
            }
            this.push(row);
            next();
        }));
    });

    externalBundles.forEach(function(eb) {
        setup(eb, function() {
            eb._offsetifyOffset = 0;
            eb.pipeline.get('sort').push(through.obj(function(row, enc, next) {
                eb._offsetifyOffset += 1;
                this.push(row);
                next();
            }));
        });
    });
};