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Mocking the httprequest with an manually defined accepttype or null [duplicate]

I have following web Api controller method.
When I run this code through web, HttpContext.Current is never null and give desired value.
public override void Post([FromBody]TestDTO model)
{
var request = HttpContext.Current.Request;
var testName = request.Headers.GetValues("OS Type")[0];
// more code
}
However, when I call this method from Unit Test, HttpContext.Current is always null.
How do i fix it?

During unit tests HttpContext is always null as it is usually populate by IIS. You have a few options around this.
Sure, you could mock the HttpContext, (which you shouldn't really do - Don't mock HttpContext!!!! He doesn't like to be mocked!),. You should really try to stay away from tight coupling with HttpContext all over your code. Try constraining it to one central area (SRP);
Instead figure out what is the functionality you would like to achieve and design an abstraction around that. This will allow for your code to be more testable as it is not so tightly coupled to HttpContext.
Based on your example you are looking to access header values. This is just an example of how to change your thinking when it comes to using HttpContext.
Your original example has this
var request = HttpContext.Current.Request;
var testName = request.Headers.GetValues("OS Type")[0];
When you are looking for something like this
var testName = myService.GetOsType();
Well then create a service that provides that
public interface IHeaderService {
string GetOsType();
}
which could have a concrete implementation like
public class MyHeaderService : IHeaderService {
public string GetOsType() {
var request = HttpContext.Current.Request;
var testName = request.Headers.GetValues("OS Type")[0];
return testName;
}
}
Now in your controller you can have your abstraction instead of having tight coupling to HttpContext
public class MyApiController : ApiController {
IHeaderService myservice;
public MyApiController(IHeaderService headers) {
myservice = headers;
}
public IHttpActionResult Post([FromBody]TestDTO model) {
var testName = myService.GetOsType();
// more code
}
}
You can later inject your concrete type to get the functionality you want.
For testing you then swap dependencies to run your test.
If the method under test is your Post() method you can create a fake dependency or use a mocking framework
[TestClass]
public class MyTestClass {
public class MyFakeHeaderService : IHeaderService {
string os;
public MyFakeHeaderService(string os) {
this.os = os;
}
public string GetOsType() {
return os;
}
}
[TestMethod]
public void TestPostMethod() {
//Arrange
IHeaderService headers = new MyFakeHeaderService("FAKE OS TYPE");
var sut = new MyApiController(headers);
var model = new TestDTO();
//Act
sut.Post(model);
//Assert
//.....
}
}

This is by design and it's always null. But there is a FakeHttpContext project on Nuget that simply you can use it.
To install FakeHttpContext, run the following command in the Package Manager Console (PMC)
Install-Package FakeHttpContext
And then use it like this:
using (new FakeHttpContext())
{
HttpContext.Current.Session["mySession"] = "This is a test";
}
Visit https://www.nuget.org/packages/FakeHttpContext to install the package
See examples on Github: https://github.com/vadimzozulya/FakeHttpContext#examples
Hope this will help :)

All you need is
controller.Request = new HttpRequestMessage();
controller.Configuration = new HttpConfiguration();
From unit-testing-controllers-in-web-api

How to properly moq ExecuteQuery method within DataContext?

I'm having a difficult time trying to understand how to appropriately return mocked data from a simulated database call in a unit test.
Here's an example method I want to unit test (GetBuildings):
public class BuildingService : IBuildingService {
public IQueryable<Building> GetBuildings(int propertyId)
{
IQueryable<Building> buildings;
// Execution path for potential exception thrown
// if (...) throw new SpecialException();
// Another execution path...
// if (...) ...
using (var context = DataContext.Instance())
{
var Params = new List<SqlParameter>
{
new SqlParameter("#PropertyId", propertyId)
};
// I need to return mocked data here...
buildings = context
.ExecuteQuery<Building>(System.Data.CommandType.StoredProcedure, "dbo.Building_List", Params.ToArray<object>())
.AsQueryable();
}
return buildings;
}
}
So GetBuildings calls a stored procedure.
So I need to mock the DataContext, that of which I can override and set a testable instance. So what happens here is, in the above example DataContext.Instance() does return the mocked object.
[TestFixture]
public class BuildingServiceTests
{
private Mock<IDataContext> _mockDataContext;
[SetUp]
public void Setup() {
_mockDataContext = new Mock<IDataContext>();
}
[TearDown]
public void TearDown() {
...
}
[Test]
public void SomeTestName() {
_mockDataContext.Setup(r =>
r.ExecuteQuery<Building>(CommandType.StoredProcedure, "someSproc"))
.Returns(new List<Building>() { new Building() { BuildingId = 1, Title = "1" }}.AsQueryable());
DataContext.SetTestableInstance(_mockDataContext.Object);
var builings = BuildingService.GetBuildings(1, 1);
// Assert...
}
Please ignore some of the parameters, like propertyId. I've stripped those out and simplified this all. I simply can't get the ExecuteQuery method to return any data.
All other simple peta-poco type methods I can mock without issue (i.e. Get, Insert, Delete).
Update
DataContext.Instance returns the active instance of the DataContext class, if exists, and if not exists, returns a new one. So the method of test under question returns the mocked instance.

Do not mock DataContext. Because mocking DataContext will produce tests tightly coupled to the implementation details of DataContext. And you will be forced to change tests for every change in the code even behavior will remain same.
Instead introduce a "DataService" interface and mock it in the tests for BuildingService.
public interface IDataService
{
IEnumerable<Building> GetBuildings(int propertyId)
}
Then, you can tests implementation of IDataService agains real database as part of integration tests or tests it agains database in memory.
If you can test with "InMemory" database (EF Core or Sqlite) - then even better -> write tests for BuildingService against actual implementation of DataContext.
In tests you should mock only external resources (web service, file system or database) or only resources which makes tests slow.
Not mocking other dependencies will save you time and give freedom while you refactoring your codebase.
After update:
Based on the updated question, where BuildingService have some execution path - you can still testing BuildingService and abstract data related logic to the IDataService.
For example below is BuildingService class
public class BuildingService
{
private readonly IDataService _dataService;
public BuildingService(IDataService dataService)
{
_dataService = dataService;
}
public IEnumerable<Building> GetBuildings(int propertyId)
{
if (propertyId < 0)
{
throw new ArgumentException("Negative id not allowed");
}
if (propertyId == 0)
{
return Enumerable.Empty<Building>();
}
return _myDataService.GetBuildingsOfProperty(int propertyId);
}
}
In tests you will create a mock for IDataService and pass it to the constructor of BuildingService
var fakeDataService = new Mock<IDataContext>();
var serviceUnderTest = new BuildingService(fakeDataService);
Then you will have tests for:
"Should throw exception when property Id is negative"
"Should return empty collection when property Id equals zero"
"Should return collection of expected buildings when valid property Id is given"
For last test case you will mock IDataService to return expected building only when correct propertyId is given to _dataService.GetBuildingsOfProperty method

In order for the mock to return data is needs to be set up to behave as expected given a provided input.
currently in the method under test it is being called like this
buildings = context
.ExecuteQuery<Building>(System.Data.CommandType.StoredProcedure, "dbo.Building_List", Params.ToArray<object>())
.AsQueryable();
Yet in the test the mock context is being setup like
_mockDataContext.Setup(r =>
r.ExecuteQuery<Building>(CommandType.StoredProcedure, "someSproc"))
.Returns(new List<Building>() { new Building() { BuildingId = 1, Title = "1" }}.AsQueryable());
Note what the mock is told to expect as parameters.
The mock will only behave as expected when provided with those parameters. Otherwise it will return null.
Consider the following example of how the test can be exercised based on the code provided in the original question.
[Test]
public void SomeTestName() {
//Arrange
var expected = new List<Building>() { new Building() { BuildingId = 1, Title = "1" }}.AsQueryable();
_mockDataContext
.Setup(_ => _.ExecuteQuery<Building>(CommandType.StoredProcedure, It.IsAny<string>(), It.IsAny<object[]>()))
.Returns(expected);
DataContext.SetTestableInstance(_mockDataContext.Object);
var subject = new BuildingService();
//Act
var actual = subject.GetBuildings(1);
// Assert...
CollectionAssert.AreEquivalent(expected, actual);
}
That said, the current design of the system under test is tightly coupled to a static dependency which is a code smell and makes the current design follow some bad practices.
The static DataContext which is currently being used as a factory should be refactored as such,
public interface IDataContextFactory {
IDataContext CreateInstance();
}
and explicitly injected into dependent classes instead of calling the static factory method
public class BuildingService : IBuildingService {
private readonly IDataContextFactory factory;
public BuildingService(IDataContextFactory factory) {
this.factory = factory
}
public IQueryable<Building> GetBuildings(int propertyId) {
IQueryable<Building> buildings;
using (var context = factory.CreateInstance()) {
var Params = new List<SqlParameter> {
new SqlParameter("#PropertyId", propertyId)
};
buildings = context
.ExecuteQuery<Building>(System.Data.CommandType.StoredProcedure, "dbo.Building_List", Params.ToArray<object>())
.AsQueryable();
}
return buildings;
}
}
This will allow for a proper mock to be created in injected into the subject under test without using a static workaround hack.
[Test]
public void SomeTestName() {
//Arrange
var expected = new List<Building>() { new Building() { BuildingId = 1, Title = "1" }}.AsQueryable();
_mockDataContext
.Setup(_ => _.ExecuteQuery<Building>(CommandType.StoredProcedure, It.IsAny<string>(), It.IsAny<object[]>()))
.Returns(expected);
var factoryMock = new Mock<IDataContextFactory>();
factoryMock
.Setup(_ => _.CreateInstance())
.Returns(_mockDataContext.Object);
var subject = new BuildingService(factoryMock.Object);
//Act
var actual = subject.GetBuildings(1);
// Assert...
CollectionAssert.AreEquivalent(expected, actual);
}

ASP.NET MVC - unit testing creation of action method URL's in a business assembly

I'm trying to write some unit tests for my ASP.NET MVC code, but I'm hitting a road block.
I have entity partial classes (in a business class library assembly) that need to determine a URL to call for an action method and controller. In order to do that, I found this snippet of code which works nicely - but alas, this uses the HttpContext.Current and thus prevents me from writing any unit tests:
public string NavigateUrl
{
get
{
HttpContextWrapper httpContextWrapper = new HttpContextWrapper(HttpContext.Current);
UrlHelper urlHelper = new UrlHelper(new RequestContext(httpContextWrapper, RouteTable.Routes.GetRouteData(httpContextWrapper)));
string url = urlHelper.Action("SomeAction", "MyController");
}
}
I am reading about the HttpContextBase - but how does this come into play here?? Or is there another way to determine an action URL inside an entity class (that is in a business assembly - NOT the MVC project and not inside a controller or other MVC infrastructure class)?
Update: I need to return this URL from an entity class as a string, since I need to use it in a grid as the navigation URL of a hyperlink. And in reality, there are numerous conditions being checked and the URL string returned can be one of several possibilities - so I cannot just replace it by a single controller call...

Create an abstraction to represent the desired functionality.
For example
public interface IUrlHelper {
string Action(string actionName, string controllerName);
//TODO: create other desired members to be exposed
}
You then create a factory for that abstraction. Since you are not injecting it into the entities we are using a service locator ani-pattern.
public static class UrlHelperFactory {
public static Func<IUrlHelper> Create = () => {
throw new NotImplementedException();
};
}
The helper and factory are not coupled to anything and could live anywhere in the solution.
The following test mocks the service to allow the entity to be tested in isolation.
[TestClass]
public class UrlHelperFactory_Should {
public class MyTestEntity {
public string NavigateUrl {
get {
var urlHelper = UrlHelperFactory.Create();
string url = urlHelper.Action("SomeAction", "MyController");
return url;
}
}
}
[TestMethod]
public void Generate_NavigationUrl() {
//Arrange
var mockHelper = Mock.Of<IUrlHelper>();
UrlHelperFactory.Create = () => {
return mockHelper;
};
var expected = "http://my_fake_url";
Mock.Get(mockHelper)
.Setup(_ => _.Action(It.IsAny<string>(), It.IsAny<string>()))
.Returns(expected);
var sut = new MyTestEntity();
//Act
var actual = sut.NavigateUrl;
//Assert
actual.Should().NotBeNullOrWhiteSpace()
.And.Be(expected);
}
}
In production code at the composition root you make sure that the factory knows how to build the service
UrlHelperFactory.Create = () => {
var httpContextWrapper = new HttpContextWrapper(HttpContext.Current);
var urlHelper = new UrlHelper(new RequestContext(httpContextWrapper, RouteTable.Routes.GetRouteData(httpContextWrapper)));
return new DefaultUrlHelperWrapper(urlHelper);
};
Where a wrapper could look like this...
internal class DefaultUrlHelperWrapper : IUrlHelper {
private UrlHelper urlHelper;
public DefaultUrlHelperWrapper(UrlHelper urlHelper) {
this.urlHelper = urlHelper;
}
public string Action(string actionName, string controllerName) {
return urlHelper.Action(actionName, controllerName);
}
//TODO: Implement other members
}

Setup a Mocked (Moq) class that only exposes properties

I am trying to mock (using Moq) a class set a return object on a class that only exposes two properties.
In my limited Moq experience I would normally use a Setup() lamda to define the method call and then Returns() to spit back the desired output.
What I am falling down on here is the Setup(). There isn't a "method" to call as the constructor does the work, populates the two properties and then returns.
My class that I want to mock...obviously dummied down:
public class CarResponse
{
public IMetaModel meta { get; set; }
public List<ICarModel> cars { get; set; }
public CarResponse(Common.Models.Car car)
{
this.cars = new List<ICarModel>();
}
}
My feeble attempt at mocking:
private Mock<CarResponse> _carResponse = new Mock<CarResponse>(MockBehavior.Strict);
_carResponse.Setup( ????? ).Returns(new CarResponse() { meta = new MetaModelV2(), cars = foo });
To further clarify...here is the code I am trying to write a unit test for:
public HttpResponseMessage AddPickup()
{
//....code removed for brevity....
//this repository is mocked and returns the object exactly as I want it
var car = carRepository.GetCar(carId);
if (!errorInfo.Any()) //This check is bogus it never gets sets
{
RequestHelper rqh = new RequestHelper();
response = rqh.CreateResponse(Request, HttpStatusCode.OK, new CarResponse(car));
}
My unit test:
[TestMethod]
public void AddValidPickupCorrectResponse()
{
//arrange
//...lots of code here left off for setting up http context etc
//act---
var response = controller.AddPickup();
//assert
}
If I were to use a precanned object as suggested how would I "hook" it to the code under test. For example I write a unit test that uses my pre-canned object instead of a Moq but how do I get that pre-canned object to be used by the SUT?

There are few problems which can get in the way of properly unit testing the above code:
new-ing up the response helper
new-ing up the CarResponseObject
In essence, unless a class in real POCO (i.e. only data with public setters and getters), using "new" is a killer for unit testing. I.e. it is not a unit test (test the unit/method in isolation). It tests the behavior of the CarResponse ctor, as well as the working of RequestHelper.
Consider the following changes:
Inject the RequestHelper (so you can mock the CreateResponse method)
Use and inject some mapping factory of sort, which can create CarResponseObjects from Car.
Consider CarResponse to implement something like IResponse, so your RequestHelper, or factory, can return interfaces.
With all of the above, your test will look like (pseudo code, not complete):
//arrange
//....
var carInDB = new Car();
_repoMock.Setup(...).Returns(car);
var carResponse = Mock.Of<IResponse>();
_mapperMock.Setup(m=>m.CreateResponse(car).Returns(carResponse);
var responseFromHelper = new WhateverResponseIsNeeded(); //(or create a new mock IResponse - note! new mock, different than car response
_helperMock.Setup(_controller.Request, HttpStatusCode.OK, carResponse).Returns(responseFromHelper);
//act
var response = _controller.AddPickup();
//assert
response.Should().Be.SameInstanceAs(responseFromHelper)

You can use SetupGet and SetupSet to mock properties. However, I don't think you can mock concrete classes.
If you are dealing with a value type you might find it easier to not bother mocking and just used a pre-canned object.

Correctly implement Unit Test

I'm practicing on writing unit tests for the first time, and I have some questions. I'll start of by explaining what I'm trying to test.
I would like to test a method which looks like this:
public bool IsAdmin(HubCallerContext hubCallerContext)
{
return hubCallerContext.User.IsInRole("admin");
}
The method is implemented in a class UserService, which is connected to a interface IUserService.
I'm trying to create 2 tests:
One with a HubCallerContext which is in the role of "admin" and will assert true.
One with a HubCallerContext which is in the role of "user" and will assert false.
I've created a new class library in my solution, where I've refrenced the project I'm testing. I've installed NUnit and Moq, and created a test class which looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ChatProj;
using NUnit.Framework;
using ChatProj.Controllers;
using Moq;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using ChatProj.DAL;
using ChatProj.Service_Layer;
using System.Threading.Tasks;
namespace ChatProj.Tests
{
[TestFixture]
public class Class1
{
[SetUp]
public void Setup()
{
}
[Test]
public void IsAdmin_CalledByAdmin_ReturnTrue()
{
UserService userService = new UserService();
bool result = userService.IsAdmin( ? );
Assert.IsTrue( result, "Something is wrong." );
}
[Test]
public void IsAdmin_CalledByUser_ReturnFalse()
{
UserService userService = new UserService();
bool result = userService.IsAdmin( ? );
Assert.IsFalse( result, "Something is wrong." );
}
}
}
Here I start to get confused. (I've marked the parameters of the IsAdmin calls with "?" because I'm not sure what to put there.)
I've read about mocks, stubs, fakes and dummies, but the definitions are to abstract for me to really grasp. I've found these definitions for example:
- Dummy objects are passed around but never actually used. Usually they are just used to fill parameter lists.
- Fake objects actually have working implementations, but usually take some shortcut which makes them not suitable for production (an in memory database is a good example).
- Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what's programmed in for the test. Stubs may also record information about calls, such as an email gateway stub that remembers the messages it 'sent', or maybe only how many messages it 'sent'.
- Mocks are objects pre-programmed with expectations which form a specification of the calls they are expected to receive.
As I've designed my test class, I would need some sort of substitution for my HubCallerContext. This is assuming I'm testing the "IsAdmin" method the right way.
So my questions are:
Am I testing the "IsAdmin" method in a good way?
How would I practically make the tests work? Do I use a mock, and in that case, could you show how I would implement that, or point me in the right direction? Here is how the HubCallerContext works for
refrence.

Assuming HubCallerContext is this one - https://github.com/SignalR/SignalR/blob/master/src/Microsoft.AspNet.SignalR.Core/Hubs/HubCallerContext.cs - then setting up the tests will be easy. You just want two mocks of IPrincipal, one of which returns true for the .IsInRole("admin") call and the other that returns false.wrap these two in mocks of IRequest.
The syntax will vary depending on the mocking framework used, but your tests will end up something like:
[Test]
public void IsAdmin_CalledByAdmin_ReturnTrue()
{
UserService userService = new UserService();
var principalMock = new Mock<IPrincipal>();
principalMock.Setup(x => x.IsInRole("admin")).Returns(true);
var requestMock = new Mock<IRequest>();
requestMock.Setup(x => x.User).Returns(principalMock.Object);
var result = userService.IsAdmin(new HubCallerContext(requestMock.Object, ""));
Assert.IsTrue( result, "Something is wrong." );
}
[Test]
public void IsAdmin_CalledByUser_ReturnFalse()
{
UserService userService = new UserService();
var principalMock = new Mock<IPrincipal>();
principalMock.Setup(x => x.IsInRole("admin")).Returns(false);
var requestMock = new Mock<IRequest>();
requestMock.Setup(x => x.User).Returns(principalMock.Object);
var result = userService.IsAdmin(new HubCallerContext(requestMock.Object, ""));
Assert.IsFalse( result, "Something is wrong." );
}
I haven't checked if the above compiles, but it is based on the syntax needed for Moq.

I think that it would be much easier for You to write these two unit tests if You would change the method under test a little (assuming it's not a part of legacy code).
If you define the method this way:
public bool IsAdmin(IPrincipal user)
{
return user.IsInRole("admin");
}
things would get pretty simple (btw. check the "Law of Demeter" ;)). You can pass in a mock object (since the user parameter is an interface - IPrincipal) returning true if the user should be in role "admin" and false otherwise.
The benefit of this solution is that You don't have to build a graph of mock objects and the arrange part of your test is pretty simple. Your tests could look somewhat like this:
[Test]
public void IsAdmin_CalledByAdminUser_ReturnTrue()
{
//Arrange
var principalMock = new Mock<IPrincipal>();
principalMock.Setup(x => x.IsInRole("admin")).Returns(true);
//Act
var userService = ...// create an instance of userService here
var result = userService.IsAdmin(principalMock);
//Assert
Assert.IsTrue(result);
}
[Test]
public void IsAdmin_CalledByNonAdminUser_ReturnFalse()
{
//Arrange
var principalMock = new Mock<IPrincipal>();
principalMock.Setup(x => x.IsInRole("admin")).Returns(false);
//Act
var userService = ...// create an instance of userService here
var result = userService.IsAdmin(principalMock);
//Assert
Assert.IsFalse(result);
}
I would recommend You to read this series of blog posts (I think it's pretty cool :)): http://www.daedtech.com/tag/unit-testing

You can get the list of roles and check for each roles using foreach.