Strict fakes

By default, FakeItEasy's fakes support what is sometimes called "loose mocking". This means that calls to any of the fake's members are allowed, even if they haven't been configured.

However, FakeItEasy also supports strict fakes, in which all calls to unconfigured members are rejected, throwing an ExpectationException. Strict fakes are created by supplying a creation option:

var foo = A.Fake<IFoo>(x => x.Strict());

After you have configured your fake in this fashion you can configure any "allowed" calls as usual, for example:

A.CallTo(() => foo.Bar()).Returns("bar");

Strict fakes are useful when it is important to ensure that no calls are made to your fake other than the ones you are expecting.

Object members

It can sometimes be inconvenient that all methods throw an exception if not configured. You might want to allow calls to methods inherited from System.Object (Equals, GetHashCode and ToString), because they're used all the time, often implicitly, and in most cases there's no real value in configuring them manually.

To achieve this, pass a StrictFakeOptions value to the Strict method when you create the fake:

// Allow calls to all object methods
var foo = A.Fake<IFoo>(x => x.Strict(StrictFakeOptions.AllowObjectMethods));

// Allow calls to ToString
var foo = A.Fake<IFoo>(x => x.Strict(StrictFakeOptions.AllowToString));

// Allow calls to Equals and GetHashCode
var foo = A.Fake<IFoo>(x => x.Strict(StrictFakeOptions.AllowEquals | StrictFakeOptions.AllowGetHashCode));

Events

By default, calls to event accessors of a strict fake will fail if the calls are not configured. Although you can manually handle event subscription or unsubscription, there's often not much value in doing this manually. You can allow a strict fake to manage events automatically by passing the AllowEvents flag to the Strict method:

var foo = A.Fake<IFoo>(x => x.Strict(StrictFakeOptions.AllowEvents));