angular-module-sort.js

var _ = require('lodash');
var through = require('through2');
var toposort = require('toposort');
var ngDeps = require('ng-dependencies');
var gutil = require('gulp-util');
var PluginError = gutil.PluginError;


module.exports = function() {
    var files = {};

    // module-file mapping
    var modules = {};

    // deps
    var deps = {};

    var transform = function(file, encoding, next) {
        var dep

        try {
            dep = ngDeps(file.contents.toString());
        } catch(err) {
            this.emit('error', new PluginError("angular-module-sort", 'Error in parsing: "' + file.relative + '", ' + err.message));
            return;
        }

        for(var k in dep.modules) {
            modules[k] = file.relative;
        }

        files[file.relative] = file;
        deps[file.relative] = dep.dependencies;

        next();
    };


    var flush = function(next) {
        for(var node in deps) {
            var edges = deps[node];

            edges = _.map(edges, function(x) { return modules[x]; });
            edges = _.filter(edges, function(x) { return !!x; } );

            deps[node] = edges;
        }

        var graph = [];
        var linked = [];

        for(var node in deps) {
            if(!deps[node].length) continue;

            linked.push(node);
            for(var i=0; i<deps[node].length; ++i) {
                graph.push( [ node, deps[node][i] ] );
                linked.push(deps[node][i]);
            }
        }

        var unused = _.difference(_.keys(files), linked);
        var solution = _.concat(toposort(graph), unused).reverse();

        for (var i=0; i<solution.length; ++i) {
            this.push(files[solution[i]])
        }

        next();
    };

    return through.obj(transform, flush)
};