CODEWITHSUNDEEP
c#visual-studiounit-testing
Sellorio
Sellorio

Reputation: 1960

Assert.AreEquals calls object.Equals irrespective of IEquatable implemenations

Today when writing and running some tests, I found out that even though my class implemented an IEquatable<MyClass> interface, an Assert.AreEqual(instanceOfMyClass, anotherInstance); resulted in false.

It turns out that no matter what, the Assert.AreEquals calls object.Equals(object obj) instead of the correct MyClass.Equals(MyClass obj) function.

Under the assumption that there is a logical reason, what is it?

Upvotes: 6

Views: 1471

Answers (1)

Stephen Byrne
Stephen Byrne

Reputation: 7505

You could try overloading == on the class in question and use the generic "Assert.AreEqual< T>" overload which uses the equals operator.

Personally I would prefer to use Assert.AreEqual(true,InstanceA.Equals(InstanceB)) as this is sure to use your Equals method; of course this assumes you have unit-tested your Equals method and are 100% certain that it works :)

As to why Assert uses object.Equals, I guess we'd have to ask the designer of the class :) But I suppose one reason is that if your Equals method is buggy, your test result is no good.

Upvotes: 2

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