Retiring a double

Understudy::forget($replaced);

For the double a test built and then replaced. $this->generator = $this->fixedGenerator('other') leaves the first one behind, still holding its stubs.

Under verifyAll(strictStubs: true) that stub is a failure about a double the test no longer uses. forget() retires it, so verification, accounting and reset stop seeing it.

Afterward

Calling anything on the object — or asking about its calls — fails with ForgottenDouble, which names forget() rather than sending you looking for a reset() you never wrote.

One-way, like every other form of forgetting here.

forget() against reset()

	Scope
Understudy::forget($double)	one double, retired from the current context
Understudy::reset()	every double, registration and transcript the test put in place

Understudy::reset();
Understudy::idle();   // true when the current context holds no doubles

The Testo and PHPUnit adapters call reset() for you after every test. Without one, call it in your own teardown.

idle() is the check a base class can make to catch a suite where something leaks between tests.