(Boiling Frogs 2017) How to increase the value of unit tests?

Transcript

1. How to increase the value of unit tests? Łukasz Wróbel Michał Kopacz
2. Please save your questions until the end of presentation
4. 75% CODE COVERAGE FOR UNIT TESTS
5. Does high code coverage imply high value of unit tests?
6. Tests without assertions
7. Workshops Value = Benefits - Costs
8. 05 06 07 08 09 04 10 TEAM CODE
9. Readable tests
10. What do we verify? /** * @dataProvider dataCaseProvider */ public function testGetStatus(array $data, $expectedIsOk, $expectedIsWarning) { … $result = $statusProvider->getStatus(); $this->assertSame($expectedIsOk, $result->isOk()); $this->assertSame($expectedIsWarning, $result->isWarning()); $this->assertSame($data, $result->getDetails()); }
11. Take a look at data provider public function dataCaseProvider() { return [ [ [ ... ], //data false, //expectedIsOk false //expectedIsWarning ], [ [ ... ], //data false, //expectedIsOk true //expectedIsWarning ], Not ok status when any delayed or failed report exists. Not ok with warning status when only delayed reports exist.
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. Example building blocks TalkStorage - save TalkManager - addMessage - hasMessage
17. State-based testing public function talk_contains_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 $talkManager->addMessage($talkId, $message); //Then $this->assertTrue($talkManager->hasMessage($talkId, $message)); }
18. Interaction testing public function saves_message_to_storage_when_it_is_being_added_to_a_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); }
19. Structure State-based testing Given When Then Interaction testing Given Expect When
20. Stub vs Mock $talkStorage->method('getMessages') ->with($talkId) ->willReturn([$message]); $talkStorage->expects($this->once()) ->method('save') ->with($talkId, $message); Stub Mock given expect
21. Testable code
22. public function handle($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?
23. BUILD REQUEST CONTENT SEND REQUEST HANDLE RESPONSE WRONG STATUS CODE INVALID RESPONSE BODY PROCESS VALID RESPONSE
24. BUILD REQUEST CONTENT SEND REQUEST HANDLE RESPONSE WRONG STATUS CODE INVALID RESPONSE BODY PROCESS VALID RESPONSE
25. Let’s test request content building $content = $item->getReportContent(); $this->updateContentWithEntity($content, $item) ->renameKeys($content) ->organizeCurrency($content) ->addFilesToReport($content, $isForced);
26. How to verify content? $this->apiClient->setRoute('api/rest/v1/debt'); $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse();
27. Verify request content in mock $this->apiClientMock->expects($this->once()) ->method('dispatch') ->with(Request::METHOD_POST, $expectedContent);
28. But it’s not the end of preparing test $response = $this->apiClient->dispatch(Request::METHOD_POST, $content)->getResponse(); ... } else { foreach ($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; } Prepare response body Mock interaction with debtReportTable
29. BUILD REQUEST CONTENT HANDLE RESPONSE WRONG STATUS CODE INVALID RESPONSE BODY PROCESS VALID RESPONSE SEND REQUEST
30. Does our object fulfill Single Responsibility Principle?
31. Separate logic BUILD REQUEST CONTENT SEND REQUEST HANDLE RESPONSE WRONG STATUS CODE INVALID RESPONSE BODY PROCESS VALID RESPONSE RequestBuilder RequestBuild er RequestBuild er WrongStatus CodeHandler
32. Decouple logic from infrastructure 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); DebtResponseToItemMapper
33. Decouple logic from infrastructure • Document Object Model (DOM) • Asynchrony (android.app.Service)
34. Tests
37. 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?
38. $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?
39. Call count and parameters verification Query Command stub mock low maintenance high value
40. Testing privacy public function testSetFilters() { $filters = ['foo' => 'bar']; /** @var Client|\PHPUnit_Framework_MockObject_MockObject $clientMock */ $clientMock = $this->getMockBuilder(Client::class) ->disableOriginalConstructor() ->setMethods(['addParameter']) ->getMock(); $halStorageAdapter = new HalStorageAdapter('/foo/bar', $clientMock); ReflectionHelper::executeMethod($halStorageAdapter, 'setFilters', [[]]); ReflectionHelper::executeMethod($halStorageAdapter, 'setFilters', [$filters]); } Cannot we test this by calling public methods?
41. Are you tempted to: • Call a private method via reflection? • Mock a private method when testing a public method? Public Private SRP Public Public +
42. Unpredictability $timestamp = time(); $this->assertEquals( date('c', $timestamp), Date::isoFormat(date(\DateTime::RFC1123, $timestamp)) ); Random value. What about Daylight Saving Time?
43. If I was about to give you…
44. Just one, the most precious piece of advice
45. Remember some of the previous examples?
46. Tests without assertions
47. $mockObjects = [ '11' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('11') ->getMock(), '22' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(5) ->andReturn('22') ->getMock(), '33' => Mockery::mock(ArticleObjectInterface::class) ->shouldReceive('getId') ->times(4) ->andReturn('33') ->getMock(), ]; Testing the implementation
48. public function handle($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
49. Would it all happen if TDD was in use?
50. Red Green Refactor TDD Cycle
51. Let me show you an example of TDD.
53. Currency converter • USD, EUR, PLN. • Rates provided by external service. • Rounding up and down.
54. A minimal increment each time.
55. Currency converter • USD, EUR, PLN. • Rates provided by external service. • Rounding up and down.
56. Building blocks Currency Money Converter
57. Step 1: expected behaviour public function returns_equal_money_if_converting_money_with_the_same_currency() { $converter = new MoneyConverter(); $convertedMoney = $converter->convert( new Money(10.50, new Currency('PLN')), new Currency('PLN'), MoneyConverter::ROUND_UP ); $this->assertEquals(new Money(10.50, new Currency('PLN')), $convertedMoney); } Currency Money Converter
58. Step 1: building blocks class MoneyConverter { const ROUND_UP = 'ROUND_UP'; public function __construct() { } public function convert(Money $fromMoney, Currency $toCurrency, $roundingMode = self::ROUND_UP) { return $fromMoney; } } Currency Money Converter
60. Currency converter • USD, EUR, PLN. • Rates provided by external service. • Rounding up and down.
61. Step 2: new building block Currency Money Converter Exchange service
62. Step 2: USD → PLN public function returns_converted_money_if_converting_with_diferent_currencies() { $exchange = $this->getMockForAbstractClass(ExchangeServiceInterface::class); $exchange->method('getRatio')->willReturn(4.0); $converter = new MoneyConverter($exchange); $convertedMoney = $converter->convert( new Money(Decimal::fromFloat(10.10, 2), new Currency('USD')), new Currency('PLN'), MoneyConverter::ROUND_UP ); $this->assertEquals( new Money(Decimal::fromFloat(40.40, 2), new Currency('PLN')), $convertedMoney ); }
63. Step 2: USD → PLN class MoneyConverter { const ROUND_UP = 'ROUND_UP'; protected $exchangeService; public function __construct(ExchangeServiceInterface $exchangeService) { $this->exchangeService = $exchangeService; } public function convert(Money $fromMoney, Currency $toCurrency, $roundingMode = self::ROUND_UP) { $ratio = $this->exchangeService->getRatio($fromMoney->getCurrency(), $toCurrency); return new Money( $fromMoney->getAmount()->mul(Decimal::fromFloat($ratio)), $toCurrency ); } }
64. Step 3: rounding up as a default strategy
65. Step 4: a possibility to round down
66. Step 5: converting from an unsupported currency
67. Step 6: converting to an unsupported currency
68. Valuable Unit Tests Workshop May 2017 fb.me/RSTkariera
69. • Do you want testing workshops to take place in your company? • We would work on your code, not on our examples. • Focus on what matters to you. • Long-term support available. Personalized workshops fb.me/QualitySheriffs
70. Questions? Michał Kopacz Łukasz Wróbel
71. Thank you!