tests.md

Tests

There are different types of tests executed:

1. Unit tests
2. Integration tests
3. End-to-end (E2E) tests

Common aspects for all tests:

• They use Mocha and Chai.
• Their files end with .spec.{ts|js} suffix.

💡 You can use path/module alias @/tests in import statements.

Unit tests

• Unit tests test each component in isolation.
• All unit tests goes under ./tests/unit.
• They rely on stubs for isolation.

Unit tests structure

• ./src/
  • Includes source code that unit tests will test.
• ./tests/unit/
  • Includes test code.
  • Tests follow same folder structure as ./src/.
    • E.g. if system under test lies in ./src/application/ApplicationFactory.ts then its tests would be in test would be at ./tests/unit/application/ApplicationFactory.spec.ts.
  • shared/
    • Includes common functionality that's shared across unit tests.
    • Assertions/:
      • Common assertions that extend Chai Assertion Library.
      • Asserting functions should start with expect prefix.
    • TestCases/
      • Shared test cases.
      • Functions that calls it() from Mocha test framework should have it prefix.
        • E.g. itEachAbsentCollectionValue().
    • Stubs/
      • Includes stubs to be able to test components in isolation.
      • Stubs have minimal and dummy behavior to be functional, they may also have spying or mocking functions.

Unit tests naming

• Each test suite first describe the system under test.
  • E.g. tests for class Application.ts are all inside Application.spec.ts.
• describe blocks tests for same function (if applicable).
  • E.g. test for run() are inside describe('run', () => ..).

Act, arrange, assert

• Tests use act, arrange and assert (AAA) pattern when applicable.
• Arrange
  • Sets up the test case.
  • Starts with comment line // arrange.
• Act
  • Executes the actual test.
  • Starts with comment line // act.
• Assert
  • Elicit some sort of expectation.
  • Starts with comment line // assert.

Integration tests

• Tests functionality of a component in combination with others (not isolated).
• Ensure dependencies to third parties work as expected.
• Defined in ./tests/integration.

E2E tests

• Test the functionality and performance of a running application.
• Vue CLI plugin e2e-cypress configures E2E tests.
• Test names and folders have logical structure based on tests executed.
• The structure is following:
  • cypress.json: Cypress configuration file.
  • ./tests/e2e/: Base Cypress folder.
    • /specs/: Test files named with .spec.js extension.
    • /plugins/index.js: Plugin file executed before loading project.
    • /support/index.js: Support file, runs before every single spec file.
    • (Ignored) /videos: Asset folder for videos taken during tests.
    • (Ignored) /screenshots: Asset folder for Screenshots taken during tests.