
Configuring Authentication in Functional testing in ASP.NET WEB API
webapi
12 Articles
In this article, let's learn about how to setup Authentication
in
Functional Test
in WebAPI
in ASP.NET Core.
Note: If you have not done so already, I recommend you read the article on Using WireMock.NET in Functional testing in ASP.NET WEB API.
Table of Contents
Introduction
In our previous article we saw how to use WireMock.NET
in functional test to validate HTTP calls. In this article,
we will see how to setup Authentication
and Authorization
in functional test in
WebAPI
in ASP.NET Core step by step. We will be using the same project that we used in our previous article.
The straight forward way to enable Authentication
and Authorization
in
Web API is to add UseAuthentication()
middleware and decorate necessary endpoints
with [Authorize]
attribute. But instead of addiing to each Endpoint
or
to each Controller
, we can do a small configuration in Program.cs
by
adding AuthorizeFilter
and enable for all Endpoints
globally.
Code Sample - Configure Authentication in Web API
Now after adding the above code in Program.cs
, if we run our tests, all our tests will fail with
401 UnAuthorized
as shown below.

Lets quickly verify if we are getting 401 UnAuthorized
from swagger. Here is the swagger response from the
WeatherForecast
endpoint.

Setup Authentication
Setting up Authentication
in Functional Test
is a bit tricky as it cannot be
mocked like unit tests. But here is plan as per official documentation.
Let's start with
AuthenticationHandler
.Code Sample - Configure Test Auth Handler for ASP.NET WEB API Functional Test
When application is started in test host add new authentication scheme (let's call it
Test
).Code Sample - Register Test Authentication Scheme in Custom Web Application Factory
Configure authentication scheme to use custom authentication handler (
TestAuthHandler
) that creates fake identity for integration tests. This handler creates fake user whenHandleAuthenticateAsync()
is called. We don't need any additional hacks to make ASP.NET Core application use this fake identity. Our integration test needs also some changes because of authentication handler.Extend test client to use authentication header with scheme
Test
.Code Sample - Setting Auth Header in Test HTTP Client
That's it now if we run our tests, it should pass. Here is the output of the test after adding the above code.

Setup Authorization
So far so good. Now the problem with the above TestHandler
is that it provides static set of claims for all the
tests. This will not be the case in real world applications. The handler provides web application with static set of claims. No matter what is the
request claims are always the same. This way it is not possible to test application with different users and roles. We need to validate
Authorization
for endpoints which require different set of claims. So we need to configure claims for each test. Here is the plan.
To make test authentication handler support different user accounts I added claims provider. This is the
class
that carries given set ofclaims
to test authentication provider. I added also some static methods to return already initialized provider with set of claims specific for role.Code Sample - Configuring Claims in ASP.NET WEB API Functional Test
Inject above instance of claims provider to test authentication handler using framework-level dependency injection.
Code Sample - Injecting claims and roles in APS.NET Web API Functional Test
That's it. Now we can use the above code to configure claims
and roles
for
each test. Let's try to test both Guest
and Admin
role. Since we added
AuthClaimsProvider.WithGuestClaims()
as default in
CustomWebApplicationFactory
we can directly add that to
GetWeatherForecastFromDatabase
endpoint and run test.

Now lets try to test the Admin
role on GetWeatherForecastFromAPI
endpoint. For this we need to replace Guest
claims with Admin
claims. We are
going to use the same Replace Service Method that we learned in
Faking Dependencies in Functional testing in ASP.NET WEB API.
The updated test code is shown below.
Code Sample - Running WEB API Functional Test with Admin Role
Thats it. We are done with setup. Now the tests will run in the following flow.
- Start Test Method.
- Create HTTP Client.
- Create WebApplicationFactory.
- Run Program.cs.
- Add Default Authentication / Override with Different Claims.
- Service Registration.
- Overriding Service Registration and Configuration with ConfigureTestServices.
- Build Web Application.
- WireMock.NET Setup.
- Test Code Execution.
Now lets run the test and see the result.

Summary
In this article, we learnt about how to setup Authentication
and Authorization
in Functional Test
in WebAPI
in ASP.NET Core. We learnt how to setup Test
Authentication Handler and Test Scheme and also learnt how to inject different users and claims in runtime. The complete source code for this article
can be found here. With this we
are completing the series on Functional Testing in ASP.NET WebAPI
. I'm happy to share my knowledge on functional
testing. Hope you enjoyed reading it.