CODEWITHSUNDEEP
c#unit-testing
Sadhurthan
Sadhurthan

Reputation: 25

Skipping private methods during unit test C#

public bool A (UserRequest foo)
{
    ClientRequest boo = B(foo); //Mapping local model to client model
    C(boo);
    return result;
}

I want to write an unit test for method A to test method B but I don't want my unit test to call method C. Method C is a private method but it makes calls to a third party client. I am unable to setup method C in my Unit Test since the type "ClientRequest" doesn't have a reference in the test case assembly. How can this be implemented without adding a reference of the client dll to my test assembly as well. How to skip calling method C ?

Upvotes: 0

Views: 806

Answers (1)

David
David

Reputation: 219037

C is a private method

Things are private for a reason. They are implementation details to which consuming code shouldn't be coupled. And unit tests are consuming code.

it makes calls to a third party client

Therein lies the problem with your unit tests. Don't try to break apart the class being tested, digging into its internals and ultimately modifying what it's doing and as a result invalidating the tests in the first place.

Instead, isolate and mock the dependency. Somewhere in C() this class has an external dependency. Instead of obscuring that dependency deep within the class, wrap it in an interface/implementation and provide that implementation to the class. (This is called Dependency Injection. There are frameworks which provide rich functionality around the concept, but the concept itself can be achieved manually for simple cases as well.)

So when application code uses this class, instances are provided with an implementation of the dependency which calls the external service. And when unit tests use this class, instances are provided with a mock implementation that pretends to call the external service.

Then your tests can include mocking the results of that service as well, triggering controlled failure responses to test how the class handles them.

Upvotes: 3

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