test: add UnsubscribeMessageHandler unit tests

test/unit/handlers/unsubscribe-message-handler.spec.ts

@@ -0,0 +1,30 @@
+import { expect } from 'chai'
+import Sinon from 'sinon'
+
+import { MessageType, UnsubscribeMessage } from '../../../src/@types/messages'
+import { IMessageHandler } from '../../../src/@types/message-handlers'
+import { IWebSocketAdapter } from '../../../src/@types/adapters'
+import { UnsubscribeMessageHandler } from '../../../src/handlers/unsubscribe-message-handler'
+import { WebSocketAdapterEvent } from '../../../src/constants/adapter'
+
+describe('UnsubscribeMessageHandler', () => {
+  let handler: IMessageHandler
+  let websocketAdapter: IWebSocketAdapter
+  let emitStub: Sinon.SinonStub
+  beforeEach(() => {
+    emitStub = Sinon.stub()
+    websocketAdapter = {
+      emit: emitStub,
+    } as any
+    handler = new UnsubscribeMessageHandler(websocketAdapter)
+  })
+
+  describe('handleMessage()', () => {
+    it('emits unsubscribe event with subscription Id', async () => {
+      const message: UnsubscribeMessage = [MessageType.CLOSE, 'subscriptionId']
+      await handler.handleMessage(message)
+
+      expect(emitStub).to.have.been.calledOnceWithExactly(WebSocketAdapterEvent.Unsubscribe, 'subscriptionId')
+    })
+  })
+})