public void Test_ImageFormat_Change_CancelsOtherRefreshTasks()
{
// Arrange.
diagram.File = new FileInfo("TestFile.puml");
diagram.ImageFile = new FileInfo("image.png");
bool killSwitch = false;
var tasks = new List <Task>(2);
compiler.Setup(c => c.CompileToImageAsync(It.IsAny <string>(), It.IsAny <ImageFormat>(), It.IsAny <CancellationToken>()))
.Returns((string content, ImageFormat format, CancellationToken token) =>
{
var task = Task.Run(() =>
{
while (!killSwitch)
{
token.ThrowIfCancellationRequested();
Thread.Sleep(100);
}
return((ImageSource)null);
}, token);
tasks.Add(task);
return(task);
});
editor = CreateEditor();
editor.RefreshAsync();
// Act.
editor.ImageFormat = ImageFormat.SVG;
// Assert.
Assert.Equal(2, tasks.Count);
AssertThat.Throws <OperationCanceledException>(() => tasks[0]);
Assert.Equal(TaskStatus.Canceled, tasks[0].Status);
killSwitch = true;
AssertThat.DoesNotThrow(() => tasks[1]);
Assert.Equal(TaskStatus.RanToCompletion, tasks[1].Status);
}