AssetSpawnerTest_Step5.cs

public class AssetSpawnerTest 
{
    [UnityTest]
    public IEnumerator Should_InstantiateObject_When_GivenStringHasNameAndPosition()
    {
        //given 
        // mock the CSV reader
        var reader = Substitute.For<ICsvReader>();
        reader.ReadNextLine().Returns("CubeX,2,3,3");
        String expectedName = "CubeX";

        String csvString =  reader.ReadNextLine();
        Vector3 expectedCoordinate = new Vector3(2f,3f,3f);

        //when
        AssetSpawner assetSpawner = new AssetSpawner();
        assetSpawner.createAGameObjectFromString(csvString);

        //then
        GameObject obj = GameObject.Find(expectedName);
        Assert.IsNotNull(obj);
        Assert.AreEqual(expectedCoordinate, obj.transform.position);
        yield return null;
    }
}