public async Task GetArticleTableData_Should_ReturnTheCorrectType() { var articles = new List <Article> { new Article(), new Article(), new Article() }.AsQueryable(); A.CallTo(() => _mediator.Send(A <GetAriclesQuery> ._, A <CancellationToken> ._)).Returns(articles); var result = await _sut.GetArticleTableData(new DataTablesParam()); result.Should().BeOfType <DataTablesResult <ArticleViewModel> >(); }