Mock-reduce NPM

MockReduce

A mock for mongodbs/mongoose's mapReduce in order to achieve testability

Installation

npm install mock-reduce

Usage

var mockReduce = require('mock-reduce');

So far I have only tested implementations with node for jasmine. Generally it should work with any other testing framework.

Using MockReduce with mongoose

var mongoose = require('mongoose');
var mockReduce = require('mock-reduce');

describe('Mongoose Test', function() {
	it('runs a mock reduce and returns the expected data', function() {
		var testData = [
			{"someId": 42, "someString": "Chickens don't clap!", "value": 4},
			{"someId": 5, "someString": "I'm on the job.", "value": 5},
			{"someId": 42, "someString": "Annyong", "value": 8},
			{"someId": 5, "someString": "Come on, this is a Bluth family celebration.", "value": 5}
		];
		
		var reducedData = [
			{"_id": 5, value: 10},
			{"_id": 42, value: 12}
		];
		
		mockReduce.install(mongoose);
		mockReduce.setNextTestData(testData);
		var model = require('./models/myModel');
		var result = model.someMethodThatCallsMapReduce();
		expect(result).toEqual(reducedData);
		mockReduce.uninstall();
	});
});

See file spec/integration/mongoose-spec.js for an extended test example

Using mockReduce with with node-mongodb-native

Caution: This feature is still work in progress. Generally it should work, I haven't fully tested it yet

var mongodb = require('mongodb');
var mockReduce = require('mock-reduce');

describe('node-mongodb-native Test', function() {
	it('runs a mock reduce and returns the expected data', function() {
		var testData = [
			{"someId": 42, "someString": "Chickens don't clap!", "value": 4},
			{"someId": 5, "someString": "I'm on the job.", "value": 5},
			{"someId": 42, "someString": "Annyong", "value": 8},
			{"someId": 5, "someString": "Come on, this is a Bluth family celebration.", "value": 5}
		];
		
		var reducedData = [
			{"_id": 5, value: 10},
			{"_id": 42, value: 12}
		];
		
		mockReduce.install(mongodb);
		mockReduce.setNextTestData(testData);
		mongodb.connect('mongodb://localhost:27017/test', function(err, db) {
			var collection = db.collection('collection_name');
			var map = function() {...}
			var reduce = function() {...}
			var options = {
				scope: {
					additional: 'variable'
				}
			};
			var result = collection.mapReduce(map, reduce, options);
		});
		expect(result).toEqual(reducedData);
		mockReduce.uninstall();
	});
});

Available methods

MockReduce stores almost every step of a map reduce operation. Try one of the following methods:

mockReduce.map.getEmits();
mockReduce.map.getMappedData();
mockReduce.reduce.getReducedData();

Supported methods

So far the following methods are supported:

map
reduce
finalize
scope
done callback

Running MockReduce's own tests

MockReduce was completely developed test-driven. If you wish to run its own tests, clone the git repo and run

npm install
npm test

Changelog

0.1.0

Security: Fix security vulnerabilities in mongoose and karma dependencies
Change: Do not put MockReduce and all subclasses into global scope but instead use require
Bugfix: Make sure index.js is required uncached in tests
Update: Bump mongoose to version 5.7.10
Update: Bump jasmine to version 3.5.0