Unit testing a Web API controller
You need to configure the setup to expect a particular behavior or argument for the test.
In this case using the It.IsAny<T>()
to tell the set up what to expect in terms of arguments will allow the test to flow as desired.
Given that the GetAll
method requires two parameters of
Func<IQueryable<T>, IOrderedQueryable<T>>
and string
, the setup configures what to do based on the values entered for those parameters.
[Test]
public async Task Get_ReturnsAAListOfBrands() {
//Arrange
var mockService = new Mock<IGenericService<Brand>>();
mockService
.Setup(repo => repo.GetAll(It.IsAny<Func<IQueryable<Brand>, IOrderedQueryable<Brand>>>(), It.IsAny<string>()))
.ReturnsAsync(Brands);
var controller = new BrandsController(mockService.Object);
//Act
var result = await controller.Get();
//Assert
//...
}
Take a look at the Moq Quickstart for a better understanding of how to use this mocking framework
JMon
Updated on July 09, 2022Comments
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JMon almost 2 years
I am fairly new to unit testing and I am trying to create a unit test for a Web API contoller that I have created which returns a list of brands.
My Web API controller
Get()
method looks like this:[HttpGet("/api/Brands/Get", Name = "GetBrands")] public async Task<IActionResult> Get() { var brands = await _brandsService.GetAll(null, "Image"); return Json(brands); }
The generic service method looks like this:
public async Task<List<T>> GetAll( Func<IQueryable<T>, IOrderedQueryable<T>> orderBy = null, string includeProperties = null) { return await _genericRepository.GetAll(orderBy, includeProperties); }
and the generic repo method looks like this:
public async Task<T> Get<TKey>(Expression<Func<T, bool>> filter = null, string includeProperties = "", bool noTracking = false) { includeProperties = includeProperties.Trim() ?? string.Empty; IQueryable<T> query = Context.Set<T>(); if (noTracking) { query.AsNoTracking(); } if (filter != null) { query = query.Where(filter); } foreach (var includeProperty in includeProperties.Split (new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)) { query = query.Include(includeProperty); } return await query.SingleOrDefaultAsync(); }
This is working and I am returning a list of brands from the database.
Now I tried to create a Unit test for this:
[SetUp] public void Setup() { Brands = new List<Brand> { new Brand { Id = 1, Name = "Adidas", ImageId = 1 }, new Brand { Id = 2, Name = "Nike", ImageId = 2 }, new Brand { Id = 3, Name = "Puma", ImageId = 3 } }; } [Test] public async Task Get_ReturnsAAListOfBrands() { //Arrange var mockService = new Mock<IGenericService<Brand>>(); mockService.Setup(repo => repo.GetAll(null, null)).Returns(Task.FromResult(Brands)); var controller = new BrandsController(mockService.Object); //Act var result = await controller.Get(); //Assert }
however the result is always null. Am I testing this correctly or do I need to change my unit test code to verify that the mock service has three items stored?
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JMon over 7 yearsjust as I was going to type that I had solved it, saw your code here :) Thanks will add this as the anwer!
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JMon over 7 yearsyes I have to investigate mocking better, that is why I am doing some examples. Thanks for your help
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JMon over 7 yearsThis example helped me a lot to come to the answer stackoverflow.com/questions/35565353/…
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JMon over 7 yearsjust one last thing, how can I verify that the result.Count() is actually 3? My JsonResult does not seem to allow me to see the Data, and I cannot get the Count() from the Value:- JsonResult actualResult = await controller.Get() as JsonResult; var data = actualResult.Data;
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Nkosi over 7 yearsNow it is a little tricky. This is however not the first time I've encountered this. check my answer here and see if it applies to your situation.