MockedTesting.swift

import XCTest
@testable import Mocking

class MockingTests: XCTestCase {
    
    let username = "testusername"
    
    /// mocked service for sending message
    var mockedMessageService = MockedMessageService()
    
    var chatRoomViewModel: ChatRoomViewModel!
    
    
    // initialization for each test
    override func setUpWithError() throws {
        // Put setup code here. This method is called before the invocation of each test method in the class.
        self.chatRoomViewModel = ChatRoomViewModel(messagingService: mockedMessageService, username: username)
    }
    
    /**
     Tests to the sending of a valid message to the mocked service
     Once completed, the error message should still be nil and the typed message should be set to empty
     */
    func testSendingValidMessage() {
        // write a message and then call send
        self.chatRoomViewModel.typedMessage = "Here is a valid message"
        self.chatRoomViewModel.sendMessage()
               
        // assert that the error message was updated
        XCTAssertNil(self.chatRoomViewModel.errorMessage)
        
        // assert that the typed message was cleared
        XCTAssertTrue(self.chatRoomViewModel.typedMessage.isEmpty)
    }
}