Google Professional Cloud Developer Question 272
Select 3Google Cloud PlatformYou are developing a serverless application on Google Cloud that uses Cloud Functions to process incoming user data. To ensure the reliability of your code, you decide to write unit tests for the function. Which of the following are best practices for writing effective unit tests for your Cloud Function?
- A
Mock external dependencies such as database connections and API calls.
- B
Write tests that depend on live cloud services to verify end-to-end functionality.
- C
Ensure that each test case is isolated and does not rely on shared state.
- D
Include tests that cover edge cases and error scenarios.
- E
Deploy the Cloud Function before running unit tests to ensure the environment is correct.
Show answer and explanation
Correct answers: A, C, D
Explanation
Unit testing focuses on testing individual components of the code in isolation. Best practices for unit tests include mocking external dependencies to isolate functionality, ensuring test cases do not share state, and including edge cases and error scenarios to improve reliability. Tests should not rely on live services or require deployments, as these aspects are covered in integration or end-to-end testing.
- A. Correct.
Correct. Mocking external dependencies ensures the unit test is focused on the function's logic and not external services. This is a best practice for unit testing.
- B. Incorrect.
Incorrect. Unit tests should focus on isolated parts of the code and not depend on live services. End-to-end testing is a separate phase of testing.
- C. Correct.
Correct. Test isolation ensures that the results of one test do not affect the others, which is critical for reliable unit tests.
- D. Correct.
Correct. Covering edge cases and error scenarios improves test coverage and ensures the application can handle unexpected inputs or errors gracefully.
- E. Incorrect.
Incorrect. Deploying the Cloud Function before testing is unnecessary for unit tests, as they should run locally and independently of the deployment environment.