Add unit tests for RedisWrapper

services/web/app/coffee/infrastructure/RedisWrapper.coffee

@@ -21,7 +21,7 @@ module.exports = Redis =
 		if redisFeatureSettings?.cluster?
 			logger.log {feature}, "creating redis-cluster client"
 			rclient = new ioredis.Cluster(redisFeatureSettings.cluster)
-			rclient._is_redis_cluster = true
+			rclient.__is_redis_cluster = true
 		else
 			logger.log {feature}, "creating redis client"
 			rclient = redis.createClient(redisFeatureSettings)

services/web/test/UnitTests/coffee/infrastructure/RedisWrapperTests.coffee

@@ -0,0 +1,66 @@
+assert = require("chai").assert
+sinon = require('sinon')
+chai = require('chai')
+should = chai.should()
+expect = chai.expect
+modulePath = "../../../../app/js/infrastructure/RedisWrapper.js"
+SandboxedModule = require('sandboxed-module')
+
+describe 'RedisWrapper', ->
+
+	beforeEach ->
+		@featureName = 'somefeature'
+		@settings =
+			redis:
+				web:
+					port:"1234"
+					host:"somewhere"
+					password: "password"
+				somefeature: {}
+		@normalRedisInstance =
+			thisIsANormalRedisInstance: true
+			n: 1
+		@clusterRedisInstance =
+			thisIsAClusterRedisInstance: true
+			n: 2
+		@redis =
+			createClient: sinon.stub().returns(@normalRedisInstance)
+		@ioredis =
+			Cluster: sinon.stub().returns(@clusterRedisInstance)
+		@logger = {log: sinon.stub()}
+
+		@RedisWrapper = SandboxedModule.require modulePath, requires:
+			'logger-sharelatex': @logger
+			'settings-sharelatex': @settings
+			'redis-sharelatex': @redis
+			'ioredis': @ioredis
+
+	describe 'client', ->
+
+		beforeEach ->
+			@call = () =>
+				@RedisWrapper.client(@featureName)
+
+		describe 'when feature uses cluster', ->
+
+			beforeEach ->
+				@settings.redis.somefeature =
+					cluster: [1, 2, 3]
+
+			it 'should return a cluster client', ->
+				client = @call()
+				expect(client).to.equal @clusterRedisInstance
+				expect(client.__is_redis_cluster).to.equal true
+
+		describe 'when feature uses normal redis', ->
+
+			beforeEach ->
+				@settings.redis.somefeature =
+					port:"1234"
+					host:"somewhere"
+					password: "password"
+
+			it 'should return a regular redis client', ->
+				client = @call()
+				expect(client).to.equal @normalRedisInstance
+				expect(client.__is_redis_cluster).to.equal undefined