@enjin/ionic1/services/merge.js

A comprehensive build system for Ionic 1 apps by Madness Labs as part of the Madness Enjin

const _ = require('lodash');


module.exports = function merge() {
    var destination = {},
        sources = [].slice.call( arguments, 0 );
    sources.forEach(function( source ) {
        var prop;
        var toTop = false;
        var overwrite = false;

        for ( prop in source ) {
            if (prop.indexOf('^') >= 0) {
                toTop = true;
                prop = prop.slice(1);
            } else if (prop.indexOf('<') >= 0) {
                prop = prop.slice(1);
                overwrite = true;
            }
            if ( prop in destination && Array.isArray( destination[ prop ] ) ) {
                if (toTop) {
                    destination[ prop ] = _.union(source['^' + prop], destination[prop]);
                    toTop = false;
                } else if (overwrite) {
                    destination[prop] = source['<' + prop];
                    overwrite = false;
                } else {
                    destination[ prop ] = _.union(destination[prop], source[ prop ]);
                }
            } else if ( prop in destination && typeof destination[ prop ] === "object" ) {
                destination[ prop ] = merge( destination[ prop ], source[ prop ] );
            } else {
                destination[ prop ] = source[ prop ];
            }
        }
    });
    return destination;
};