"No expectations were configured for the mock object ..." notice is emitted when `with()` is used without `expects()`

[sebastianbergmann]

I believe that the notice that is currently triggered on PHPUnit 12.5 is luring people into a trap. Tests are being refactored from mocks to stubs because of that notice, only to discover that the freshly refactored tests break as soon as the project upgrades to PHPUnit 13.

Originally posted by @derrabus in #6504

[sebastianbergmann]

This is the code that triggers the notice in question:

phpunit/src/Framework/TestCase.php

Lines 1405 to 1422 in 1686e30

	private function verifyMockObjects(): void
	{
	$allowsMockObjectsWithoutExpectations = $this->allowsMockObjectsWithoutExpectations();
	$isPhpunitTestSuite = str_starts_with($this::class, 'PHPUnit\\');
	foreach ($this->mockObjects as $mockObject) {
	if (!$mockObject['mockObject']->__phpunit_hasMatchers()) {
	if (!$allowsMockObjectsWithoutExpectations && !$isPhpunitTestSuite) {
	Event\Facade::emitter()->testTriggeredPhpunitNotice(
	$this->testValueObjectForEvents,
	sprintf(
	'No expectations were configured for the mock object for %s. ' .
	'Consider refactoring your test code to use a test stub instead. ' .
	'The #[AllowMockObjectsWithoutExpectations] attribute can be used to opt out of this check.',
	$mockObject['type'],
	),
	);
	}

When with() is used without expects(), the __phpunit_hasMatchers() method used in the code shown above returns false:

1. The Method trait internally calls ->expects(new AnyInvokedCount), implicitly creating a matcher with the AnyInvokedCount invocation rule

2. This creates a Matcher object whose $invocationRule is an AnyInvokedCount instance

3. Matcher::hasMatchers() is:

   public function hasMatchers(): bool
   {
       return !$this->invocationRule instanceof AnyInvokedCount;
   }

   Since the rule is AnyInvokedCount, this returns false.

4. InvocationHandler::hasMatchers() iterates all matchers and returns true only if any matcher's hasMatchers() returns true. Since none do, it returns false.

5. __phpunit_hasMatchers() delegates directly to InvocationHandler::hasMatchers(), so it also returns false.

AnyInvokedCount means "any number of invocations is acceptable", it is the $this->any() rule. It represents a test stub (configuration of indirect input), not an expectation (verification of indirect output). The hasMatchers() method is specifically asking "does this mock object have any invocation count expectations that need to be verified?" A with() constraint only validates parameters when the method is called, but AnyInvokedCount means the method does not need to be called at all, so there is nothing to verify at teardown.

To not trigger the notice in question when with() is used without expects() we need to query the mock object differently.