Moq + Unit Testing - System.Reflection.TargetParameterCountException: Parameter count mismatch

Question

I\'m tring to use a lambda with a multiple-params function but Moq throws this exception at runtime when I attempt to call the mock.Object.Convert(value, null, null, n

Answer 1

In my case, I thought that the type in Returns<> is the output type, but in fact it was the input type(s).

So if you have a method

public virtual string Foo(int a, int b) { ... }

The correct clause is .Returns(...), NOT .Returns(...) which is what I thought initially.

My mistake was because I was testing a function with the same input and return type initially - for example public virtual string Foo(string a).