PHPUnit: mock non-existing classes

Yes, it is possible to stub/mock classes that do not exist with PHPUnit. Simply do

 $this->getMockBuilder('NameOfClass')->setMethods(array('foo'))->getMock();

to create an object of non-existant class NameOfClass that provides one method, foo(), that can be configured using the API as usual.

Since PHPUnit 9, you shall replace :

• 'NameOfClass' by \stdClass::class
• setMethods by addMethods

$this->getMockBuilder(\stdclass::class)->addMethods(array('foo'))->getMock();

The accepted answer is perfect, except that since PHPUnit 9 there is an issue, if you need to mock a class that is required to be of a certain instance. In that case \stdclass::class cannot be used.

And using

$this->getMockBuilder('UnexistentClass')->addMethods(['foo'])->getMock();

will result in Class UnexistentClass does not exist, because addMethod checks the given methods against the given class methods.

In case anybody else is having the same issue, luckly setMethods still works, so this still works in PHPUnit 9

$this->getMockBuilder('UnexistentClass')->setMethods(['foo'])->getMock();

Note though that setMethods will be removed in PHPUnit 10

Hopefully at that time there will be a fix for this issue. Like for example checking if allowMockingUnknownTypes is set to true. If that check is implemented this will then work too:

$this->getMockBuilder('UnexistentClass')->allowMockingUnknownTypes()
->addMethods(['foo'])->getMock();