• Getting started
• Creating a substitute
• Setting a return value
• Return for specific args
• Return for any args
• Return from a function
• Multiple return values
• Replacing return values
• Checking received calls
• Clearing received calls
• Argument matchers
• Callbacks, void calls and When..Do
• Throwing exceptions
• Safe configuration and overlapping calls
• Raising events
• Auto and recursive mocks
• Setting out and ref args
• Actions with argument matchers
• Checking call order
• Partial subs and test spies
• Return for all calls of a type
• Threading
• Compatibility argument matchers
• NSubstitute.Analyzers
• How NSubstitute works
• Search

Return for any args

A call can be configured to return a value regardless of the arguments passed using the ReturnsForAnyArgs() extension method.

calculator.Add(1, 2).ReturnsForAnyArgs(100); 
Assert.AreEqual(100, calculator.Add(1, 2));
Assert.AreEqual(100, calculator.Add(-7, 15));

Tip! You can also use the default C# keyword for better readability:

calculator.Add(default, default).ReturnsForAnyArgs(100);

The same behaviour can also be achieved using argument matchers: it is simply a shortcut for replacing each argument with Arg.Any<T>().

ReturnsForAnyArgs() has the same overloads as Returns(), so you can also specify multiple return values or calculated return values using this approach.