C#•16mo ago

Test ASP.API controller with xUnit: can't assert Type

Hello 👋 I hope my question is not too dumb but I m stuck on the testing of my API controller. (It is my first test project) Me controller looks exactly like this :

[HttpGet]
    public async Task<ActionResult<IEnumerable<RecipeDto>>> GetRecipes(
        [FromQuery] int pageNumber,
        [FromQuery] int pageSize,
        [FromQuery] string? title,
        [FromQuery] string? searchQuery)
    {
        try
        {
            (IEnumerable<Recipe> recipes, PaginationMetadata metadata) = await _recipeService.GetPage(pageNumber, pageSize, title, searchQuery);

            if (recipes is null || recipes.Any() == false)
            {
                _logger.LogInformationGetAll(nameof(Recipe));
                return NotFound();
            }

            IEnumerable<RecipeDto> response = recipes.Select(r => r.MapToRecipeDto());

            Response.Headers.Add("X-Pagination", JsonSerializer.Serialize(metadata));
            return Ok(response);
        }
        catch (Exception ex)
        {
            _logger.LogCriticalGetAll(nameof(Recipe), ex);
            return this.InternalErrorCustom();
        }
    }

[HttpGet]
    public async Task<ActionResult<IEnumerable<RecipeDto>>> GetRecipes(
        [FromQuery] int pageNumber,
        [FromQuery] int pageSize,
        [FromQuery] string? title,
        [FromQuery] string? searchQuery)
    {
        try
        {
            (IEnumerable<Recipe> recipes, PaginationMetadata metadata) = await _recipeService.GetPage(pageNumber, pageSize, title, searchQuery);

            if (recipes is null || recipes.Any() == false)
            {
                _logger.LogInformationGetAll(nameof(Recipe));
                return NotFound();
            }

            IEnumerable<RecipeDto> response = recipes.Select(r => r.MapToRecipeDto());

            Response.Headers.Add("X-Pagination", JsonSerializer.Serialize(metadata));
            return Ok(response);
        }
        catch (Exception ex)
        {
            _logger.LogCriticalGetAll(nameof(Recipe), ex);
            return this.InternalErrorCustom();
        }
    }

And i am trying to test the first case : Recipes.Any() = false, in this test :

 [Fact]
    public async Task GetRecipes_Empty_ReturnsNotFound()
    {

        // Arrange
        Tools.RecipeService recipeService = new Tools.RecipeService();
        RecipesController controller = new RecipesController(new NullLogger<RecipesController>(), recipeService);

        // Act
        ActionResult<IEnumerable<RecipeDto>> result = await controller.GetRecipes(1, 5, null, null);

        // Assert
        Assert.NotNull(result);
        Assert.IsType<ActionResult<IEnumerable<RecipeDto>>>(result);
        Assert.IsType<NotFoundResult>(result);
        Assert.Equal(controller.NotFound(), result);
    }

 [Fact]
    public async Task GetRecipes_Empty_ReturnsNotFound()
    {

        // Arrange
        Tools.RecipeService recipeService = new Tools.RecipeService();
        RecipesController controller = new RecipesController(new NullLogger<RecipesController>(), recipeService);

        // Act
        ActionResult<IEnumerable<RecipeDto>> result = await controller.GetRecipes(1, 5, null, null);

        // Assert
        Assert.NotNull(result);
        Assert.IsType<ActionResult<IEnumerable<RecipeDto>>>(result);
        Assert.IsType<NotFoundResult>(result);
        Assert.Equal(controller.NotFound(), result);
    }

But it doesnt work. Both my IsType<NotFoundResult>(result) and Equal(controller.NotFound(), result) fail. How could i test this please? 😁

51 Replies

PhilémonOP•16mo ago

Oh yes maybe i should say that i made a "test" recipe service in Tools.RecipeService, looking like this :

public async Task<(IEnumerable<Recipe> recipes, PaginationMetadata metadata)> GetPage(int pageNumber, int pageSize, string? title, string? searchQuery)
    {
        return await Task.FromResult((Enumerable.Empty<Recipe>(), new PaginationMetadata(1,5,0)));
    }

public async Task<(IEnumerable<Recipe> recipes, PaginationMetadata metadata)> GetPage(int pageNumber, int pageSize, string? title, string? searchQuery)
    {
        return await Task.FromResult((Enumerable.Empty<Recipe>(), new PaginationMetadata(1,5,0)));
    }

PhilémonOP•16mo ago

Test fails but they look the same to me 🥲

PhilémonOP•16mo ago

Ok sorry but I found the answer after being stuck for hours, it was as simple as :

ActionResult<IEnumerable<RecipeDto>> response = await controller.GetRecipes(1, 5, null, null);
        **var result = response.Result;**
        // Assert
        Assert.NotNull(result);
        Assert.IsType<NotFoundResult>(result);

ActionResult<IEnumerable<RecipeDto>> response = await controller.GetRecipes(1, 5, null, null);
        **var result = response.Result;**
        // Assert
        Assert.NotNull(result);
        Assert.IsType<NotFoundResult>(result);

I need to take the .Result of it 🤣

Angius•16mo ago

Or better yet, await it

PhilémonOP•16mo ago

What do you think i should await ? I dont understand

Angius•16mo ago

The thing you're trying to .Result

Mayor McCheese•16mo ago

I think I'm blind I don't see a .Result

PhilémonOP•16mo ago

"ActionResult" does not contain a definition for GetAwaiter it says var result = response.Result

Angius•16mo ago

Ah, response is not a Task?

PhilémonOP•16mo ago

i tried to put it in bold with two ** but it didnt work 🤣

Angius•16mo ago

It's just a completely unrelated type that has a .Result property?

PhilémonOP•16mo ago

it is an action result

Angius•16mo ago

If so, carry on

PhilémonOP•16mo ago

ok ok :p thank you !

Mayor McCheese•16mo ago

I'm totally blind; I don't see that

PhilémonOP•16mo ago

Here 😁

Mayor McCheese•16mo ago

oh okay NIT: I hate testing controllers this way

PhilémonOP•16mo ago

how would you do it ?

Mayor McCheese•16mo ago

WebApplicationFactory and call the endpoint

public class BasicTests 
    : IClassFixture<WebApplicationFactory<Program>>
{
    private readonly WebApplicationFactory<Program> _factory;

    public BasicTests(WebApplicationFactory<Program> factory)
    {
        _factory = factory;
    }

    [Theory]
    [InlineData("/")]
    [InlineData("/Index")]
    [InlineData("/About")]
    [InlineData("/Privacy")]
    [InlineData("/Contact")]
    public async Task Get_EndpointsReturnSuccessAndCorrectContentType(string url)
    {
        // Arrange
        var client = _factory.CreateClient();

        // Act
        var response = await client.GetAsync(url);

        // Assert
        response.EnsureSuccessStatusCode(); // Status Code 200-299
        Assert.Equal("text/html; charset=utf-8", 
            response.Content.Headers.ContentType.ToString());
    }
}

public class BasicTests 
    : IClassFixture<WebApplicationFactory<Program>>
{
    private readonly WebApplicationFactory<Program> _factory;

    public BasicTests(WebApplicationFactory<Program> factory)
    {
        _factory = factory;
    }

    [Theory]
    [InlineData("/")]
    [InlineData("/Index")]
    [InlineData("/About")]
    [InlineData("/Privacy")]
    [InlineData("/Contact")]
    public async Task Get_EndpointsReturnSuccessAndCorrectContentType(string url)
    {
        // Arrange
        var client = _factory.CreateClient();

        // Act
        var response = await client.GetAsync(url);

        // Assert
        response.EnsureSuccessStatusCode(); // Status Code 200-299
        Assert.Equal("text/html; charset=utf-8", 
            response.Content.Headers.ContentType.ToString());
    }
}

https://learn.microsoft.com/en-us/aspnet/core/test/integration-tests?view=aspnetcore-7.0 I personally will only unit test things that provide a quantifiable advantage The tests you're writing just make code harder to change and add negligible value

PhilémonOP•16mo ago

I had doubt that unit testing my api was really useful, for real I thought about integration test but it seems a step harder Maybe it will be more useful than unit testing I see

Mayor McCheese•16mo ago

so, by quantifiable, let's say you wrote conversions for dry ingredients from metric to imperial and vice versa that's worth testing

PhilémonOP•16mo ago

Yes i have none of that haha

Mayor McCheese•16mo ago

I get that; but if you did lets say that you had a recipe doubler as well so more ingredients might change time sorta thing and you have a really smart way to do that totally unit testable

PhilémonOP•16mo ago

Ok thank you a lot i see better now

Mayor McCheese•16mo ago

controller? meh; who cares; just call it like an entry point to your application same as a user would it can be harder

PhilémonOP•16mo ago

May i ask you, when you do integration tests, do you test on the real DB ? I was thinking of giving test data to my test project, using copy of my Seed class that seeds my DB with entity framework

Mayor McCheese•16mo ago

yesnt WebApplicationFactory has some tools to swap things out; it's worth some research so swap out the db for sqlite or something ( there are known compatability issues for some edge cases )

PhilémonOP•16mo ago

Ok thank you @Ruskell McCheese I will make integration tests, honnestly thats what i wanted to do at start 🤣 But i was kinda afraid the step was too big since i didnt make any test project yet

Mayor McCheese•16mo ago

but in a pipeline for instance; I might spin up a db in docker and seed with data and test against that

PhilémonOP•16mo ago

docker ❤️ i need to try this too that s a really good opportunity here

Mayor McCheese•16mo ago

some folks go for various "cobra" metrics; and it's a separate issue

PhilémonOP•16mo ago

i m HYPED for real

Mayor McCheese•16mo ago

cobra ~= perverse incentive so like, peeps will say, you need 90% code coverage; now you're in perverse incentive land meaning you'll do a lot of silly things to get there that aren't valuable just to get there ( not quite a perverse incentive, but )

PhilémonOP•16mo ago

oh so 90% is already too much if i understand well ? and you can use Cobra to get to the 90% ?

Mayor McCheese•16mo ago

The cobra bit, is that back in day in India, they started paying bounties on cobra snake heads, so now, perversely I'm going to just raise snakes and kill them for the bounty so at some point someone will say, "hey this is a bad idea we're just creating more snakes" and stop paying bounties so I'll let all my snakes go so now we have a larger snake problem

PhilémonOP•16mo ago

oh ok i see i will keep that in mind while doing my tests

Mayor McCheese•16mo ago

so using unit tests to get to high code coverage, now code is very ossified and hard to change

PhilémonOP•16mo ago

testing the most important, where the bugs are likely to be existing, right ?

Mayor McCheese•16mo ago

ossified == turning to stone

PhilémonOP•16mo ago

yes its like in french, os = bone ok nice

Mayor McCheese•16mo ago

This is the exciting part about something like web application factory; when you hit your controller, you're just going to also test everything in that stack

PhilémonOP•16mo ago

it looks like a lot of fun, i can learn docker and sql lite and the tests at the same time, 3 birds with one stone 😮

Mayor McCheese•16mo ago

with some creativity you can create tons of scenarios from a single test... Theory supports other types of "inputs" more than just inline data

[Theory]
[InlineData("/")]
[InlineData("/Index")]
[InlineData("/About")]
[InlineData("/Privacy")]
[InlineData("/Contact")]

[Theory]
[InlineData("/")]
[InlineData("/Index")]
[InlineData("/About")]
[InlineData("/Privacy")]
[InlineData("/Contact")]

and suddenly you have hundreds of tests for scenarios that actually make sense

PhilémonOP•16mo ago

i was thinking that my unit tests of api endpoint was kind of useless 🤣

Mayor McCheese•16mo ago

https://www.thomasbogholm.net/2021/12/01/xunit-using-theorydata-with-theory/ they can be valuable, but that will come with experience

PhilémonOP•16mo ago

Yes i guess, but not with endpoints like mine i think Thank you for all the resources and info

Mayor McCheese•16mo ago

hey no problem NB: this is a highly opinionated area results may vary

PhilémonOP•16mo ago

I see, but i know it will help me learn new things so it will be helpful to make tests that way, even if not every one agrees plus, its kind of what i wanted to do at start haha 😅

Becquerel•16mo ago

Just dropping in to mention that if you are interested in using Docker to test database related stuff Testcontainers is a really cool package to check out makes creating and cleaning up Docker images real easy 🙂

PhilémonOP•16mo ago

I will check this out, thank you 😉

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Test ASP.API controller with xUnit: can't assert Type