𝗕𝗲𝘁𝘁𝗲𝗿 𝗤𝗔 𝗪𝗶𝘁𝗵 𝗦𝘂𝗿𝗿𝗼𝗴𝗮𝘁𝗲 𝗧𝗲𝘀𝘁𝗶𝗻𝗴

𝗕𝗲𝘁𝘁𝗲𝗿 𝗤𝗔 𝗪𝗶𝘁𝗵 𝗦𝘂𝗿𝗿𝗼𝗴𝗮𝘁𝗲 𝗧𝗲𝘀𝘁𝗶𝗻𝗴

Unit tests miss bugs. You need to find errors early. Surrogate testing helps. It uses test doubles and mutation testing. This improves your test quality. It keeps your speed high.

Test doubles stand in for real parts of your app. Use mocks, stubs, and fakes. They stop flaky tests. They keep your tests focused.

• Use API stubs for external services.
• Use fake data stores for databases.
• Simulate timeouts and failures.

Mutation testing checks your tests. It makes small changes to your code. If tests do not fail, you have a gap.

• Use Stryker for TypeScript.
• Use MutPy for Python.
• Start with small, important modules.

Build a better pipeline in these steps:

• Pick critical paths like payments.
• Create a library of doubles.
• Write tests for success and failure.
• Run mutation tests for feedback.
• Add these to your CI pipeline.

Keep your doubles simple. Do not add business logic to them. Match them to your real API. Use dependency injection to swap them in.

Source: https://dev.to/therizwansaleem/surrogate-testing-building-a-robust-qa-pipeline-with-mutation-testing-and-test-doubles-3e8a