C#•5mo ago

How do I test a running API?

Hey, I'm using NUnit to test my application. Now, my application project consists of two parts: The application itself and an API server. I'm running a HttpClient.GetAsync command on the application using my localhost URL for the API. var response = client.GetAsync("http://localhost:5255/api/product/sort="+ (int)sort +"&filter="+ (int)filter).Result; I want to test this method or rather the API calls. How do I do that? AFAIK I can't test when the application is running which I have to to get my API running? I hope someone can help me. Thank you very much! 🙂

34 Replies

Angius•5mo ago

First and foremost throw that .Result off the bridge and use proper async/await Test the API as an API, not through the lens of the client

Anton•5mo ago

you probably want TestServer look it up

Angius•5mo ago

You want to mock API responses to test the client, and use integration testing with WebApplicationFactory to test the API As a side note, use string interpolation

DultusOP•5mo ago

I thought to test it in case the URL changes for example. I have made 7 tests for the API itself. Will do as well, thank you! Hmm, I call a similar command within the constructor. How would I go about that?

Angius•5mo ago

Start by removing async code from the constructor Then await the async call

DultusOP•5mo ago

Yeah but for that the method has to be async?

Angius•5mo ago

Yes

DultusOP•5mo ago

        public ProductViewModel()
        {
           await GetProductsAsync();
        }
        private async Task GetProductsAsync()
        {
            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync("http://localhost:5255/api/product");
                response.EnsureSuccessStatusCode();
                if (response != null)
                {
                    var jsonString = response.Content.ReadAsStringAsync().Result;
                    Products = JsonConvert.DeserializeObject<List<ProductItem>>(jsonString);
                }
            }
            return;
        }

        public ProductViewModel()
        {
           await GetProductsAsync();
        }
        private async Task GetProductsAsync()
        {
            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync("http://localhost:5255/api/product");
                response.EnsureSuccessStatusCode();
                if (response != null)
                {
                    var jsonString = response.Content.ReadAsStringAsync().Result;
                    Products = JsonConvert.DeserializeObject<List<ProductItem>>(jsonString);
                }
            }
            return;
        }

How would I async the constructor?

Angius•5mo ago

You would not Long-running code should not be running in the constructor

DultusOP•5mo ago

Ah, yeah, makes sense. I'll just create the object and call it afterwards.

Angius•5mo ago

(as a side note, you can safely depete the Newtonsoft dependency and just use the built-in JSON serializer) What is the client, btw? Some WPF app? A Blazor SPA?

DultusOP•5mo ago

A Blazor Web Application

Angius•5mo ago

Ah, that makes things simple Use dependency injection Create a product service/repository/whatever, that will have the GetProductsAsync() method that returns a List<ProductItem> Inject the HttpClientFactory into that And inject that into whatever component needs those products By injecting the client factory you get the benefit of every call being able to use the same URL So should it change, you only change it in one place You could also consider using a typed client, which would elimnate the need for a service/repo layer

DultusOP•5mo ago

    public class ProductViewModel : INotifyPropertyChanged
    {
        private List<ProductItem> products;
        public List<ProductItem> Products
        {
            get => products;
            set
            {
                products = value;
                OnPropertyChanged();
            }
        }

        public ProductViewModel() { }
        public async Task GetProductsAsync()
        {
            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync("http://localhost:5255/api/product");
                response.EnsureSuccessStatusCode();
                if (response != null)
                {
                    var jsonString = response.Content.ReadAsStringAsync().Result;
                    Products = JsonConvert.DeserializeObject<List<ProductItem>>(jsonString);
                }
            }
            return;
        }

    public class ProductViewModel : INotifyPropertyChanged
    {
        private List<ProductItem> products;
        public List<ProductItem> Products
        {
            get => products;
            set
            {
                products = value;
                OnPropertyChanged();
            }
        }

        public ProductViewModel() { }
        public async Task GetProductsAsync()
        {
            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync("http://localhost:5255/api/product");
                response.EnsureSuccessStatusCode();
                if (response != null)
                {
                    var jsonString = response.Content.ReadAsStringAsync().Result;
                    Products = JsonConvert.DeserializeObject<List<ProductItem>>(jsonString);
                }
            }
            return;
        }

And

@page "/products"
@using ProductDisplayerApp.ViewModels
@inject ProductViewModel ViewModel
@code {
    protected override async Task OnInitializedAsync()
    {
        await ViewModel.GetProductsAsync();
    }
    public void Refresh()
    {
        StateHasChanged();
    }
}

@page "/products"
@using ProductDisplayerApp.ViewModels
@inject ProductViewModel ViewModel
@code {
    protected override async Task OnInitializedAsync()
    {
        await ViewModel.GetProductsAsync();
    }
    public void Refresh()
    {
        StateHasChanged();
    }
}

Is how I have it right now.

Angius•5mo ago

Ah, huh, MVVM? Can't say I ever used it with Blazor

DultusOP•5mo ago

I just try to have some sort of standard, not gonna lie. 😄 I'm not used to Blazor at all!

Angius•5mo ago

What's the Refresh() and StateHasChanged() do? Properties in Blazor are reactive by default

DultusOP•5mo ago

They get called within the home file.

@if (isListView)
{
    <ProductListView @ref="productListView" />
}
else{
    <BottleView @ref="bottleView"/>
}
...
private void Filter()
{
    // Load the filtered list of products into the current view model
    if (filter == Models.Filter.Unfiltered)
    {
        filter = Models.Filter.Filtered;
    }
    else if (filter == Models.Filter.Filtered)
    {
        filter = Models.Filter.Unfiltered;
    }
    ViewModel.Sort_and_Filter(sortation, filter);
    RefreshViews();
}
private void RefreshViews()
{
    if (isListView)
    {
        productListView.Refresh();
    }
    else
    {
        bottleView.Refresh();
    }
    StateHasChanged();
}

@if (isListView)
{
    <ProductListView @ref="productListView" />
}
else{
    <BottleView @ref="bottleView"/>
}
...
private void Filter()
{
    // Load the filtered list of products into the current view model
    if (filter == Models.Filter.Unfiltered)
    {
        filter = Models.Filter.Filtered;
    }
    else if (filter == Models.Filter.Filtered)
    {
        filter = Models.Filter.Unfiltered;
    }
    ViewModel.Sort_and_Filter(sortation, filter);
    RefreshViews();
}
private void RefreshViews()
{
    if (isListView)
    {
        productListView.Refresh();
    }
    else
    {
        bottleView.Refresh();
    }
    StateHasChanged();
}

Because otherwise when I tried to filter or sort the view it did not update.

Angius•5mo ago

@inject ProductClient _client

<ul>
    @foreach(var p in Products)
    {
        <li>@p.Name</li>
    }
</ul>
<button @onclick="Load">Refresh</button>

@code {
    private List<Product> Products { get; set; }
    
    private async Task Load()
    {
        Products = await _client.GetAllProducts();
    }
    
    protected override async Task OnInitializedAsync()
    {
       await Load();
    }
}

@inject ProductClient _client

<ul>
    @foreach(var p in Products)
    {
        <li>@p.Name</li>
    }
</ul>
<button @onclick="Load">Refresh</button>

@code {
    private List<Product> Products { get; set; }
    
    private async Task Load()
    {
        Products = await _client.GetAllProducts();
    }
    
    protected override async Task OnInitializedAsync()
    {
       await Load();
    }
}

is probably how I'd do it If you need filtering or sorting, it would also be handled by that typed client/repo/service/whatever Make Load() public, give it arguments what to sort by and filter by Then call it from outside the component if need be From your sort dropdown component or w/e

DultusOP•5mo ago

Sadly just saw that OnInitailized is getting called too late because the products need to be loaded into the grid before I load the page.

Angius•5mo ago

wtf why

DultusOP•5mo ago

System.NullReferenceException: "Object reference not set to an instance of an object."

Because foreach'ing through the products throws me this error.

Angius•5mo ago

Ah, derp

private List<Product> Products { get; set; } = [];

private List<Product> Products { get; set; } = [];

There, solved It will start as an empty list, not a null

DultusOP•5mo ago

Yeah, that works. @ZZZZZZZZZZZZZZZZZZZZZZZZZ One more question;

[HttpGet("product/sort={sort}&filter={filter}")]
public async Task<object> GetSortedProduct(int sort, int filter)
{
    Sortation sortation = (Sortation)sort;
    Filter filteration = (Filter)filter;
    var ProductStorage = (await Product.GetProductAsync());


    if (ProductStorage == null)
    {
        return StatusCode(404);
    }


    if (sortation != Sortation.Unsorted)
    {
        Product.Sort(ref ProductStorage, ref sortation);
    }
    if (filteration != Filter.Unfiltered)
    {
        Product.Filter(ref ProductStorage, ref filteration);
    }
    return Ok(ProductStorage);
}

[HttpGet("product/sort={sort}&filter={filter}")]
public async Task<object> GetSortedProduct(int sort, int filter)
{
    Sortation sortation = (Sortation)sort;
    Filter filteration = (Filter)filter;
    var ProductStorage = (await Product.GetProductAsync());


    if (ProductStorage == null)
    {
        return StatusCode(404);
    }


    if (sortation != Sortation.Unsorted)
    {
        Product.Sort(ref ProductStorage, ref sortation);
    }
    if (filteration != Filter.Unfiltered)
    {
        Product.Filter(ref ProductStorage, ref filteration);
    }
    return Ok(ProductStorage);
}

I'm perfectly fine not using async methods for sorting and filtering, right?

Angius•5mo ago

object 💀 And you have an await here, so this method does have to be async Also, I'd recommend doing the sorting and filtering on the database Not on the data that was fetched from the db Assuming Product.GetProductAsync() gets the products from the database, that is Ah, then that's fine

DultusOP•5mo ago

It's just a JSON, so I'm a bit limited. 😄 This yes, just thinking about the Sort and Filter methods. Because I don't await those but could build them this way.

Angius•5mo ago

Do they do anything asynchronously?

DultusOP•5mo ago

Not really. Just wondering if it affects the API itself.

Angius•5mo ago

If a method does not await anything it does not need to be async

DultusOP•5mo ago

Alright, just thinking about performance. 😄 It's actually a project for a job interview so I want to be as precise as possible. Though I'm a bit unsure what to return if not an object - because I want status codes but also content to be send back. x) Should I build a wrapper around the objects to include the status code and the object?

Angius•5mo ago

ActionResult<List<Product>> for example Or even better, the typed result Result<OkResult<List<Product>>, NotFoundResult> As a side note, don't use StatusCode when you're returning a common code Return NotFound() instead Unauthorized() instead of 505, etc

DultusOP•5mo ago

When it's async I'd need to wrap the result into a Task as well, right? Task<Result<OkResult<List<Product>>, NotFoundResult>>

Angius•5mo ago

So something like

[HttpGet("product/sort={sort}&filter={filter}")]
public async Results<Ok<List<Product>>, NotFound> GetSortedProduct(Sorting sort, Filter filter)
{
    var products = await Product.GetProductAsync();

    if (products is null)
    {
        return TypedResults.NotFound();
    }

    if (sort != Sortation.Unsorted)
    {
        Product.Sort(ref products, ref sort);
    }
    if (filter != Filter.Unfiltered)
    {
        Product.Filter(ref products, ref filter);
    }
    return TypedResults.Ok(products);
}

[HttpGet("product/sort={sort}&filter={filter}")]
public async Results<Ok<List<Product>>, NotFound> GetSortedProduct(Sorting sort, Filter filter)
{
    var products = await Product.GetProductAsync();

    if (products is null)
    {
        return TypedResults.NotFound();
    }

    if (sort != Sortation.Unsorted)
    {
        Product.Sort(ref products, ref sort);
    }
    if (filter != Filter.Unfiltered)
    {
        Product.Filter(ref products, ref filter);
    }
    return TypedResults.Ok(products);
}

Yep You can make it easier on yourself using a type alias

//...
using SortedProducts = Results<Ok<List<Product>>, NotFound>;

namespace MyApp;

[Route("[controller]")]
public class ProductsController : ControllerBase
{
    [HttpGet]
    public async Task<SortedProducts> GetSortedProduct(Sorting sort, Filter filter)
    {
        //...
    }
    //...
}

//...
using SortedProducts = Results<Ok<List<Product>>, NotFound>;

namespace MyApp;

[Route("[controller]")]
public class ProductsController : ControllerBase
{
    [HttpGet]
    public async Task<SortedProducts> GetSortedProduct(Sorting sort, Filter filter)
    {
        //...
    }
    //...
}

Actually sort and filter will automatically bind to query parameters anyway No need to make it a part of the path

DultusOP•5mo ago

Ah, okay. Helps me a lot. Thank you!

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How do I test a running API?