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Testing Microservices: Testing Microservices: Testing Microservices: fast and with confidence fast and with confidence fast and with confidence
Stephan Jaensch Stephan Jaensch Stephan Jaensch @s_jaensch @s_jaensch @s_jaensch
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TestingMicroservices: TestingMicroservices: TestingMicroservices: - - PowerPoint PPT Presentation
TestingMicroservices: TestingMicroservices: TestingMicroservices: - - PowerPoint PPT Presentation
TestingMicroservices: TestingMicroservices: TestingMicroservices: fastandwithconfidence fastandwithconfidence fastandwithconfidence StephanJaensch StephanJaensch StephanJaensch @s_jaensch @s_jaensch @s_jaensch 1 2
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Two years ago... Two years ago...
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The Testing Pyramid The Testing Pyramid
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The Testing Pyramid The Testing Pyramid
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Why end to end tests? Why end to end tests?
Source: https://www.slideshare.net/danveloper/microservices-the-right-way
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Flakes Flakes
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Improving speed and reducing Improving speed and reducing flakiness flakiness
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Contract testing Contract testing
Bob Reselman Contract Testing is writing tests to ensure that the explicit and implicit contracts of your microservices work as advertised.
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A service call at Yelp A service call at Yelp
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Anatomy of a client library request Anatomy of a client library request
Construct request REMOTE SERVICE HTTP response Marshal data Validate request HTTP request Adapt HTTP response Validate response Unmarshal response 11
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Inject mock in client library Inject mock in client library
Construct request REMOTE SERVICE HTTP response Marshal data Validate request HTTP request Adapt HTTP response Validate response Unmarshal response Mock 12
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Patching the client library Patching the client library
class TestExampleHappyhourClient(): @pytest.fixture(autouse=True) def setup_teardown(self): with patch_clientlib() as mock_client: yield def test_get_hours_simple(): hours = get_hours_simple() assert hours == { 'SUN': {'time_start': 0, 'time_end': 0}, 'MON': {'time_start': 0, 'time_end': 0}, ... }
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Providing a mock response Providing a mock response
class TestExampleHappyhourClient(): @pytest.fixture(autouse=True) def setup_teardown(self): with patch_clientlib() as mock_client: mock_client.hours.getHours\ .set_return_value_and_status_code( return_value={ 'FRI': {'time_start': 21, 'time_end': 23}, 'SAT': {'time_start': 21, 'time_end': 23}, 'SUN': {'time_start': 21, 'time_end': 23}, }, status_code=200, ) yield
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Mocks with errors Mocks with errors
jsonschema.exceptions.ValidationError: 'id' is a required property
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Conclusion Conclusion
End to end tests don't scale infinitely Contract tests are supposed to help We can leverage existing infrastructure to do consumer driven contract testing (sort of) We're relying on the fact that the service adheres to the specification
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@s_jaensch
Questions? Questions?
sjaensch@yelp.com
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