getMockBuilder(ApiLegacyRequestService::class) ->disableOriginalConstructor() ->getMock(); $apiLegacyStorageTest = $this ->getMockBuilder(ApiLegacyStorage::class) ->setConstructorArgs([$apiLegacyRequestService]) ->setMethodsExcept(['read']) ->getMock(); $file = $this->getMockBuilder(File::class)->getMock(); $file->method('getId')->willReturn(123); $apiLegacyRequestService ->expects(self::once()) ->method('getContent') ->with('api/files/123/download') ->willReturn('xyz'); $result = $apiLegacyStorageTest->read($file); $this->assertEquals('xyz', $result); } }