CODEWITHSUNDEEP
c#nunitmoq
cd491415
cd491415

Reputation: 891

How to mock an Exception on a get-property with Moq

I have a getter only property like

public ICar Car
{
  { 
    get 
    {
      return _car ?? (_car = GetCar());
    }
  }
}

GetCar() will throw NotSupportedException under certain circumstances and I want to unit test this. I am using Moq.

I am trying to use this in my unit test but it does not work on properties, only on methods

var sut = new CarProcessor(...); //init subject under test
Assert.Throws<NotSupportedException>(() => sut.Car); //evaluate result of Car property

This wont compile and it says "Only assignment call, increment, decrement, await and new object expression can be used as a statement" error.

Doing same as above for a method instead property works fine.

Upvotes: 0

Views: 318

Answers (1)

Jonathon Chase
Jonathon Chase

Reputation: 9714

You can work around this by assigning the property in a statement lambda, like so:

Assert.Throws<NotSupportedException>(() => { var _ = sut.Car; });

This will attempt to assign the property to a throwaway variable _ (C# 7+ only, use x if you're compiling against a a lower language level), which should compile just fine.

Upvotes: 3

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