BaseTest.fs

module BaseTest = 

    [<TestFixture>]
    [<AbstractClass>]   
    type public AggregateTest<'TState, 'TCommand, 'TEvent>() =
    
        abstract member For: Aggregate<'TState, 'TCommand, 'TEvent>
        abstract member Given: 'TEvent list
        abstract member When: 'TCommand
        abstract member Then: ('TState -> unit)
        abstract member Fail: (System.Exception -> unit)

        [<Test>]
        member this.Test() =
            let aggregate = this.For
            let events = this.Given
            let state = events |> Seq.fold aggregate.Apply aggregate.Zero
            try
                aggregate.Execute state this.When
                |> aggregate.Apply state
                |> this.Then
            with
            | :? System.Exception as ex -> this.Fail(ex)

GameBoardTest.fs

module GameboardTest = 

    [<AbstractClass>]
    type public GameboardTest() =
        inherit AggregateTest<State, Command, Event>()
        override this.Fail = fun e -> ()
        override this.Then = fun s -> ()
        override this.For = {
            Zero = State.Zero;
            Apply = Apply;
            Execute = Execute
        }


    let player1 = new Player("player1")
    let player2 = new Player("player2")
    
    let participant1 = new Participant(player1, Blue)
    let participant2 = new Participant(player2, Red)

    type public CreateTest() =
        inherit GameboardTest()
        override this.Given = []
        override this.When = Create
        override this.Then = fun s -> Assert.IsNotEmpty s.Tiles

    type public BuildRoadTest() =
        inherit GameboardTest()
        override this.Given = [Created(CreateBoard())]
        override this.When = BuildRoad({P1 = {X = 0.0; Y = 320.0}; P2 = {X = 0.0; Y = 400.0}}, participant1)
        override this.Then = fun s -> 
            Assert.IsNotEmpty(s.Roads)
            let roadCreated = s.Roads |> Seq.head
            Assert.AreEqual(participant1, roadCreated.Participant)
            Assert.AreEqual({P1 = {X = 0.0; Y = 320.0}; P2 = {X = 0.0; Y = 400.0}}, roadCreated.Property)

    type public BuildRoadAlreadyOccupiedTest() =
        inherit GameboardTest()
        override this.Given = [
            Created(CreateBoard()); 
            RoadBuilt({P1 = {X = 0.0; Y = 320.0}; P2 = {X = 0.0; Y = 400.0}}, participant1)
        ]
        //flip the points (complimentary should work aswell)
        override this.When = BuildRoad({P2 = {X = 0.0; Y = 320.0}; P1 = {X = 0.0; Y = 400.0}}, participant1)
        override this.Fail = fun (e) -> 
            Assert.AreEqual("This edge is already occupied", e.Message)