Create XCTest

.swift

func testCreate() {

        //Setup fixture
        let usersURL = URL(string: APIDemo.baseURL + "/users")
        URLProtocolMock.testURLs = [usersURL: Data(Fixtures.createUserResponse.utf8)]
        
        //1) When is valid
        APIDemo.publisher = customPublisher
        URLProtocolMock.response = mocks.validResponse
        let publisher = APIDemo.create(user: self.mocks.user)

        let validTest = evalValidResponseTest(publisher: publisher)
        wait(for: validTest.expectations, timeout: testTimeout)
        validTest.cancellable?.cancel()
        
        //2) When has invalid response
        URLProtocolMock.response = mocks.invalidResponse
        let publisher2 = APIDemo.create(user: self.mocks.user)
        let invalidTest = evalInvalidResponseTest(publisher: publisher2)
        wait(for: invalidTest.expectations, timeout: testTimeout)
        invalidTest.cancellable?.cancel()
        
        //3) When has invalid data and valid response
        URLProtocolMock.testURLs[usersURL] = Data("{{}".utf8)
        URLProtocolMock.response = mocks.validResponse
        
        let publisher3 = APIDemo.create(user: self.mocks.user)
        let invalidTest3 = evalInvalidResponseTest(publisher: publisher3)
        wait(for: invalidTest3.expectations, timeout: testTimeout)
        invalidTest3.cancellable?.cancel()
        
        //4) Network Failure
        URLProtocolMock.response = mocks.validResponse
        URLProtocolMock.error = mocks.networkError
        
        let publisher4 = APIDemo.create(user: self.mocks.user)
        let invalidTest4 = evalInvalidResponseTest(publisher: publisher4)
        wait(for: invalidTest4.expectations, timeout: testTimeout)
        invalidTest4.cancellable?.cancel()
    }