mungedb-aggregate/test/lib/pipeline/Pipeline.js

"use strict";
var assert = require("assert"),
	Pipeline = require("../../../lib/pipeline/Pipeline"),
	DocumentSource = require('../../../lib/pipeline/documentSources/DocumentSource');


module.exports = {

	"Pipeline": {

		before: function(){

			Pipeline.stageDesc.$test = (function(){
				var klass = function TestDocumentSource(options, ctx){
					base.call(this, ctx);
					
					this.shouldCoalesce = options.coalesce;
					this.coalesceWasCalled = false;
					this.optimizeWasCalled = false;
					
					this.current = 5;
					
				}, TestDocumentSource = klass, base = DocumentSource, proto = klass.prototype = Object.create(base.prototype, {constructor:{value:klass}});
				
				
				proto.coalesce = function(){
					this.coalesceWasCalled = true;
					var c = this.shouldCoalesce;//only coalesce with the first thing we find
					this.shouldCoalesce = false;
					return c;
				};

				proto.optimize = function(){
					this.optimizeWasCalled = true;
				};
				
				proto.eof = function(){
					return this.current < 0;
				};

				proto.advance = function(){
					this.current = this.current - 1;
					return !this.eof();
				};

				proto.getCurrent = function(){
					return this.current;
				};

				klass.createFromJson = function(options, ctx){
					return new TestDocumentSource(options, ctx);
				};
				
				return klass;
			})().createFromJson;

		},

		"parseCommand": {

			"should throw Error if given non-objects in the array": function () {
				assert.throws(function(){
					Pipeline.parseCommand({pipeline:[5]});
				});
			},

			"should throw Error if given objects with more / less than one field": function () {
				assert.throws(function(){
					Pipeline.parseCommand({pipeline:[{}]});
					Pipeline.parseCommand({pipeline:[{a:1,b:2}]});
				});
			},

			"should throw Error on unknown document sources": function () {
				assert.throws(function(){
					Pipeline.parseCommand({pipeline:[{$foo:"$sdfdf"}]});
				});
			},

			"should swap $match and $sort if the $match immediately follows the $sort": function () {
				var p = Pipeline.parseCommand({pipeline:[{$sort:{"xyz":1}}, {$match:{}}]});
				assert.equal(p.sourceVector[0].constructor.matchName, "$match");
				assert.equal(p.sourceVector[1].constructor.sortName, "$sort");
			},

			"should attempt to coalesce all sources": function () {
				var p = Pipeline.parseCommand({pipeline:[{$test:{coalesce:false}}, {$test:{coalesce:true}}, {$test:{coalesce:false}}, {$test:{coalesce:false}}]});
				assert.equal(p.sourceVector.length, 3);
				p.sourceVector.slice(0,-1).forEach(function(source){
					assert.equal(source.coalesceWasCalled, true);
				});
				assert.equal(p.sourceVector[p.sourceVector.length -1].coalesceWasCalled, false);
			},

			"should optimize all sources": function () {
				var p = Pipeline.parseCommand({pipeline:[{$test:{coalesce:false}}, {$test:{coalesce:false}}]});
				p.sourceVector.forEach(function(source){
					assert.equal(source.optimizeWasCalled, true);
				});
			}

		},

		"#run": {

			"should set the parent source for all sources in the pipeline except the first one": function (next) {
				var p = Pipeline.parseCommand({pipeline:[{$test:{coalesce:false}}, {$test:{coalesce:false}}, {$test:{coalesce:false}}]});
				p.run(new DocumentSource({}), function(err, results){
					assert.equal(p.sourceVector[1].source, p.sourceVector[0]);
					assert.equal(p.sourceVector[2].source, p.sourceVector[1]);
					return next();
				});
			},

			"should iterate through sources and return resultant array": function (next) {
				var p = Pipeline.parseCommand({pipeline:[{$test:{coalesce:false}}, {$test:{coalesce:false}}, {$test:{coalesce:false}}]});
				p.run(new DocumentSource({}), function(err, results){
					assert.deepEqual(results.result, [5,4,3,2,1,0]); //see the test source for why this should be so
					return next();
				});
			},

			"should call callback with errors from pipeline components": function (next) {
				// The $foo part is invalid and causes a throw.
				assert.throws(function(){
					Pipeline.parseCommand({pipeline:[{$match:{$foo:{bar:"baz"}}}]});
				});
			}

		}

	}

};

if (!module.parent)(new(require("mocha"))()).ui("exports").reporter("spec").addFile(__filename).grep(process.env.MOCHA_GREP || '').run(process.exit);