(PHPers Wrocław #5) How to write valuable unit test?

Jak zwiększyć wartość testów jednostkowych?

Michał Kopacz, Łukasz Wróbel

Czy wiecie, jak zdefiniować czym są "dobre" testy jednostkowe? Główną obiektywną miarą ich jakości jest poziom pokrycia kodu testami. Tylko czy to wystarczy? Wprowadzając w RST zasadę 75% pokrycia kodu testami wiedzieliśmy, że samo kryterium liczbowe to za mało. Można przecież napisać testy dające 100% pokrycia, ale nie zawierające żadnej asercji. Nie chcąc bazować wyłącznie na poziomie pokrycia kodu, postanowiliśmy zebrać nasze doświadczenia w pisaniu testów jednostkowych i zorganizowaliśmy dla naszych zespołów deweloperskich warsztaty. Jeżeli chcesz się dowiedzieć: jak nazywać testy i nadawać im czytelną strukturę, co to znaczy "testowalny kod", jak się uchronić przed kruchością testów, czy też jaka jest różnica między pisaniem testów przed i po implementacji, to zobacz prezentację, w której dzielimy się zdobytą wiedzą i przykładami omawianymi na warsztatach.

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1. How to write valuable unit tests? Łukasz Wróbel Michał Kopacz
2. Please save your questions until the end of presentation
4. 75% CODE COVERAGE FOR UNIT TESTS
5. Tests without assertions
6. How we can measure quality of tests?
7. Workshops Value = Benefits - Costs
8. 05 06 07 08 09 04 10 TEAM CODE
9. Readable tests
10. Data Provider /** * @dataProvider dataCaseProvider */ public function testGetStatus(array $data, $expectedIsOk, $expectedIsWarning) { $statusProviderMock = $this->getMockBuilder(QueueStatusProvider::class) ->setConstructorArgs([$this->repositoryMock]) ->setMethods(['getData']) ->getMock(); $statusProviderMock->expects($this->once()) ->method('getData') ->willReturn($data); $result = $statusProviderMock->getStatus(); $this->assertInstanceOf(StatusInterface::class, $result); $this->assertSame($expectedIsOk, $result->isOk()); $this->assertSame($expectedIsWarning, $result->isWarning()); $this->assertSame($data, $result->getDetails()); }
11. Data Provider public function dataCaseProvider() { return [ [ [ QueueStatusProvider::SECTION_WARNING => [ QueueStatusProvider::STATUS_CATEGORY_DELAYED => [1], ], QueueStatusProvider::SECTION_FAILURE => [ QueueStatusProvider::STATUS_CATEGORY_DELAYED => [1, 2, 3], QueueStatusProvider::STATUS_CATEGORY_FAILED => [], ], ], false, //expectedIsOk false //expectedIsWarning ], [ [ QueueStatusProvider::SECTION_WARNING => [ QueueStatusProvider::STATUS_CATEGORY_DELAYED => [1], ], QueueStatusProvider::SECTION_FAILURE => [ QueueStatusProvider::STATUS_CATEGORY_DELAYED => [], QueueStatusProvider::STATUS_CATEGORY_FAILED => [], ], ], false, //expectedIsOk true //expectedIsWarning ],
12. Separate each case /** * @test */ public function returns_not_ok_status_when_any_delayed_or_failed_report_exists() /** * @test */ public function returns_not_ok_with_warning_status_when_only_delayed_reports_exist()
13. Name should include scenario under which it’s being tested. returns_not_ok_status_when_any_delayed_or_failed_report_exists
14. Name should say something about the expected behaviour. returns_not_ok_status_when_any_delayed_or_failed_report_exists
15. Expected behaviour state-based testing interaction testing
16. Examples /** * @test */ public function talk_contain_message_after_it_has_been_added() { //Given $message = new Message("test message"); $talkId = 1; $talkStorage = $this->getMock(TalkStorage::class); $talkManager = new TalkManager($talkStorage); $talkStorage->method('getMessages') ->with($talkId) ->willReturn([$message]); //When $talkManager->add($talkId, $message); //Then $this->assertTrue($talkManager->hasMessage($talkId, $message)); } /** * @test */ public function saved_message_in_storage_when_it_is_adding_to_talk() { //Given $message = new Message("test message"); $talkId = 1; $talkStorage = $this->getMock(TalkStorage::class); $talkManager = new TalkManager($talkStorage); //Expect $talkStorage->expects($this->once()) ->method('save') ->with($talkId, $message); //When $talkManager->add($talkId, $message); }
17. Structure Given When Then Given Expect When
18. Stub vs Mock $talkStorage->method('getMessages') ->with($talkId) ->willReturn([$message]); $talkStorage->expects($this->once()) ->method('save') ->with($talkId, $message); Stub Mock given expect
19. Testable code
20. public function handle($id, $isForced = false) { $logger = $this->debugLogger; $item = $this->debtReportTable->getById($id); if (!$item) { throw new DebtReportNotFoundException('Report does not exist: ' . $id); } $content = $item->getReportContent(); $this->updateContentWithEntity($content, $item) ->renameKeys($content) ->organizeCurrency($content) ->addFilesToReport($content, $isForced); $this->apiClient->setRoute('api/rest/v1/debt'); $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse(); if (in_array($this->apiClient->getResponseStatusCode(), $this->AdaUnrecoverableFailureCodes)) { $responseRawBody = $this->apiClient->getResponseRawBody(); if ($logger) { $logger->critical(sprintf('Debt reporting failed at AdaSoftware request with status: [%s: %s]', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus())); $logger->debug(sprintf('ADA API internal server error [%s: %s]. Reason: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($responseRawBody, true))); } $this->sendMailWithLog($item, $responseRawBody); $item->setStatus(DebtReport::STATUS_FAILED); $this->updateReportStats($item); $this->debtReportTable->save($item); throw new InternalSwApiException($responseRawBody); } elseif (!$this->apiClient->hasValidData() || !isset($response['_embedded']['debts']) || !is_array($response['_embedded']['debts'])) { $responseRawBody = $this->apiClient->getResponseRawBody(); if ($logger) { $logger->critical('Debt reporting failed at AdaSoftware request.'); $logger->debug(sprintf('ADA API failure [%s: %s]. Response body: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($responseRawBody, true))); } $this->sendMailWithLog($item, $responseRawBody); $item->setStatus(DebtReport::STATUS_FAILED); $this->debtReportTable->save($item); } else { if ($logger) { $logger->debug(sprintf('ADA API success [%s: %s]. Response body: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($this->apiClient->getResponseRawBody(), true))); } foreach ($response['_embedded']['debts'] as $debt) { $link = new DebtToDebtReport(); $link->setId($debt['id']); $item->addDebtToDebtReport($link); } $item->setStatus(DebtReport::STATUS_COMPLETED); $this->debtReportTable->save($item); $this->updateReportStats($item); return true; } return false; } Testable code?
21. BUILD REQUEST CONTENT SEND REQUEST HANDLE RESPONSE WRONG STATUS CODE INVALID RESPONSE BODY PROCESS VALID RESPONSE
22. Let’s test request content building $content = $item->getReportContent(); $this->updateContentWithEntity($content, $item) ->renameKeys($content) ->organizeCurrency($content) ->addFilesToReport($content, $isForced); $this->apiClient->setRoute('api/rest/v1/debt'); $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse();
23. Verify request content in mock $this->apiClientMock->expects($this->once()) ->method('dispatch') ->with(Request::METHOD_POST, $expectedContent);
24. But it’s not the end of preparing test ... $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse(); } else { if ($logger) { $logger->debug(sprintf('ADA API success [%s: %s]. Response body: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($this->apiClient->getResponseRawBody(), true))); } foreach ($response['_embedded']['debts'] as $debt) { $link = new DebtToDebtReport(); $link->setId($debt['id']); $item->addDebtToDebtReport($link); } $item->setStatus(DebtReport::STATUS_COMPLETED); $this->debtReportTable->save($item); $this->updateReportStats($item); return true; } return false; } ...
25. Double other collaborators protected function setUp() { $this->statsServiceMock = $this->getMockBuilder(\Inkasso\Statistics\DebtReportStatisticsService::class) ->disableOriginalConstructor()->getMock(); $this->apiClientMock = $this->getMockBuilder(\ApiClient\Client\AdaSoftware::class) ->disableOriginalConstructor()->getMock(); $this->debtReportTable = $this->getMockBuilder(\DebtReport\Entity\Table\DebtReportTable::class) ->disableOriginalConstructor()->getMock(); $this->storageAdapterMock = $this->getMockBuilder(\FileStorage\Storage\StorageAdapterInterface::class) ->disableOriginalConstructor()->getMock(); $this->consumer = new ReportHandler($this->statsServiceMock, $this->storageAdapterMock, $this->debtReportTable, $this->apiClientMock); }
26. Does our object fulfill Single Responsibility Principle?
27. Separate logic • RequestBuilder • Strategies for handling response
28. Decouple logic from infrastructure • DebtResponseToItemsMapper • Document Object Model (DOM) • Asynchrony (android.app.Service) foreach ($response['_embedded']['debts'] as $debt) { $link = new DebtToDebtReport(); $link->setId($debt['id']); $item->addDebtToDebtReport($link); } $item->setStatus(DebtReport::STATUS_COMPLETED); $this->debtReportTable->save($item); infra logic
29. Tests
32. public function test_fetchAll_emptyLanguage() { $paramsMock = $this->getMock('Zend\Stdlib\Parameters'); $paramsMock->expects($this->at(0)) ->method('get') ->with($this->equalTo('labels')) ->will($this->returnValue('')); $paramsMock->expects($this->at(1)) ->method('get') ->with($this->equalTo('module')) ->will($this->returnValue('')); $paramsMock->expects($this->at(2)) ->method('get') ->with($this->equalTo('lang')) ->will($this->returnValue('')); } Call order Is the call order relevant? How is it connected to the result? Are empty strings important?
33. $mockObjects = [ '11' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('11') ->getMock(), '22' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(5) ->andReturn('22') ->getMock(), '33' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('33') ->getMock(), ]; Call count Are these performance tests?
34. Call count and parameters verification Query Command stub mock low maintenance high value
35. Testing privacy public function testSetFilters() { $filters = ['foo' => 'bar']; /** @var Client|\PHPUnit_Framework_MockObject_MockObject $clientMock */ $clientMock = $this->getMockBuilder(Client::class) ->disableOriginalConstructor() ->setMethods(['addParameter']) ->getMock(); $clientMock ->expects($this->once()) ->method('addParameter') ->with( $this->equalTo(HalStorageAdapter::FILTER_PARAM), $this->equalTo(json_encode($filters)) ); $halStorageAdapter = new HalStorageAdapter('/foo/bar', $clientMock); ReflectionHelper::executeMethod($halStorageAdapter, 'setFilters', [[]]); ReflectionHelper::executeMethod($halStorageAdapter, 'setFilters', [$filters]); } Cannot we test this by calling public methods?
36. Are you tempted to: • Call a private method via reflection? • Mock a private method when testing a public method? Public Private SRP Public Public +
37. Unpredictability $timestamp = time(); $this->assertEquals( date('c', $timestamp), Date::isoFormat(date(\DateTime::RFC1123, $timestamp)) ); random() What about Daylight Saving Time?
38. If I was about to give you…
39. Just one, the most precious piece of advice
40. Remember some of the previous examples?
41. Tests without assertions
42. $mockObjects = [ '11' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('11') ->getMock(), '22' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(5) ->andReturn('22') ->getMock(), '33' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('33') ->getMock(), ]; Testing the implementation
43. public function handle($id, $isForced = false) { $logger = $this->debugLogger; $item = $this->debtReportTable->getById($id); if (!$item) { throw new DebtReportNotFoundException('Report does not exist: ' . $id); } $content = $item->getReportContent(); $this->updateContentWithEntity($content, $item) ->renameKeys($content) ->organizeCurrency($content) ->addFilesToReport($content, $isForced); $this->apiClient->setRoute('api/rest/v1/debt'); $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse(); if (in_array($this->apiClient->getResponseStatusCode(), $this->AdaUnrecoverableFailureCodes)) { $responseRawBody = $this->apiClient->getResponseRawBody(); if ($logger) { $logger->critical(sprintf('Debt reporting failed at AdaSoftware request with status: [%s: %s]', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus())); $logger->debug(sprintf('ADA API internal server error [%s: %s]. Reason: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($responseRawBody, true))); } $this->sendMailWithLog($item, $responseRawBody); $item->setStatus(DebtReport::STATUS_FAILED); $this->updateReportStats($item); $this->debtReportTable->save($item); throw new InternalSwApiException($responseRawBody); } elseif (!$this->apiClient->hasValidData() || !isset($response['_embedded']['debts']) || !is_array($response['_embedded']['debts'])) { $responseRawBody = $this->apiClient->getResponseRawBody(); if ($logger) { $logger->critical('Debt reporting failed at AdaSoftware request.'); $logger->debug(sprintf('ADA API failure [%s: %s]. Response body: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($responseRawBody, true))); } $this->sendMailWithLog($item, $responseRawBody); $item->setStatus(DebtReport::STATUS_FAILED); $this->debtReportTable->save($item); } else { if ($logger) { $logger->debug(sprintf('ADA API success [%s: %s]. Response body: %s', $this->apiClient->getResponseStatusCode(), $this->apiClient->getResponseStatus(), var_export($this->apiClient->getResponseRawBody(), true))); } foreach ($response['_embedded']['debts'] as $debt) { $link = new DebtToDebtReport(); $link->setId($debt['id']); $item->addDebtToDebtReport($link); } $item->setStatus(DebtReport::STATUS_COMPLETED); $this->debtReportTable->save($item); $this->updateReportStats($item); return true; } return false; } Big chunk of code
44. Would it all happen if…
45. Red Green Refactor* TDD
47. Invitation for workshops
48. 3 XII 2016 (Saturday) 9:30-17:00 RST (Racławicka 2) http://rst.com.pl/unittestsworkshop/
50. Assignment • No time spent on the basics. • Equal level. • Engagement.
51. Questions? Michał Kopacz Łukasz Wróbel
52. Thank you!