How to write test in node.js
- 1. How to write test in Node.js Jason Lin ([email protected]) 2017/08 1
- 2. Why ā¢ Why we need to write test? ā Few questions ā¢ How do you know the status of the system? ā¢ How do you know the code you commit meet the requirement? ā¢ How do you know the code you commit wonāt break other module? ā¢ Side effect? ā Problems: Manual test is trivial and time consuming ā Solution: write test and make it run automatically 2
- 3. What ā¢ Testing methodologies 3 Test the individual component Test the component groups Test the integrated systems Test the final system Reference: https://www.inflectra.com/ideas/topic/testing-methodologies.aspx
- 4. What ā¢ Testing methodologies ā Unit Test ā¢ Test on isolated component (public) ā¢ Shouldnāt have dependencies (file, db, 3rd Party Lib, ā¦) ā Integrate Test ā¢ Testing on multiple components ā¢ Verify the interaction between components ā¢ It may rely on dependencies ā System Test ā¢ Concerned with the behavior of the full system 4
- 5. What ā¢ Development process ā TDD (Test Driven Development) ā¢ Write test first ā¢ Just meet the requirement ā¢ Never over-design 5 Reference: https://www.allaboutcircuits.com/technical-articles/how-test- driven-development-can-help-you-write-better-unit-tests/
- 6. What ā¢ Development process ā BDD (Behavior Driven Development) ā¢ Develop software correctly and develop correct software ā¢ Focused on the business behaviors ā¢ Spec as test case ā PM and target user wrote stories together ā PM and engineers wrote the scenarios together ā¢ Story (gherkin syntax) ā¢ Scenario (gherkin syntax) 6 As a <type of stakeholder> I want <a feature> So that <some goal can be met> Given <a context> When <an event happens> Then <an outcome should occur>
- 7. What ā¢ Development process ā BDD (Behavior Driven Development) ā¢ Example 7 Feature: QIoT Backup As an administrator, I want to backup the whole QIoT So that I can restore the system Scenario: Backup QIoT Given the administrator logged in to QIoT When administrator press the backup button Then the backup zip file should be downloaded automatically
- 8. What ā¢ Development process ā BDD + TDD 8 Reference: https://www.getzephyr.com/insights/collaboration-backbone-agile- testing
- 9. How ā¢ How can we write test in Node.js? ā Test Framework ā¢ Mocha / Jasmine / Ava ā¢ Cucumber ā Assertion Library ā¢ Chai ā Test Double Library ā¢ Sinon / Mockery / Proxyquire 9
- 10. Test Framework - Mocha ā¢ What is Mocha ā Run on Node.js/Browser ā Supports BDD/TDD ā Choose any assertion library ā Choose any mocking library ā Asynchronous function and promise function support ā Highlights slow tests 10
- 11. Test Framework - Mocha ā¢ How to install & run Mocha 11 Testing Result:
- 12. Test Framework - Mocha ā¢ How to write test with Mocha ā BDD style (default) 12
- 13. Test Framework - Mocha ā¢ How to write test with Mocha ā TDD style 13
- 14. Test Framework - Cucumber ā¢ Features ā Support Node.js / Java / Ruby ā Deliver executable spec document ā Support Gherkin DSL syntax ā¢ Example ā 1. Installation: npm install cucumber ā 2. Wrote feature file 14 features/grocery.feature
- 15. Test Framework - Cucumber ā¢ Examples ā 3. Generate template ā¢ ./node_modules/cucumber/bin/cucumber.js ā 4. Implement test case by template 15 features/step_definitions/grocery.js
- 16. Test Framework - Cucumber ā¢ Examples ā 5. Run test ā¢ ./node_modules/cucumber/bin/cucumber.js 16
- 17. Test Framework ā¢ Mocha or Cucumber? ā Mocha are friendly to programmers ā¢ Focus on test case ā Cucumber are friendly to non-programmers ā¢ Deliver executable spec 17
- 18. Assertion Library - Chai.js ā¢ Run on Node.js/Browser ā¢ Provide there ways of assertions 18
- 19. Test Double ā¢ What is test double? ā Replace the target object for testing purpose ā Type ā¢ Dummy: passed around but never actually used ā¢ Stub: Provide a canned response to method calls ā¢ Mock: Verifies behavior to a method (Stub + expected) ā¢ Spy: Proxy to real objects and record all kinds of things ā¢ Fake: Business behavior simulators 19
- 20. Test Double ā¢ Sinon.js ā spy/stub/mock library ā Installation: npm install sinon ā Spy: 20
- 21. Test Double ā¢ Sinon.js ā Stub ā Mock 21