public function testCalledChangesState() { $callback = new Callback(function () { // empty }); $this->assertFalse($callback->wasCalled()); $this->assertEquals(0, $callback->getCalled()); $callback->call(); $this->assertTrue($callback->wasCalled()); $this->assertEquals(1, $callback->getCalled()); $callback->call(); $this->assertEquals(2, $callback->getCalled()); }