Chapter 9 · Part 2

Testing Strategy in the Pipeline

A focused chapter on testing strategy in the pipeline, with practical delivery concerns, trade-offs, and the operational questions behind CI/CD work.

9-1

What Testing in a Pipeline Actually Needs to Do

Every time a developer pushes code, there is one question that needs an answer: is this change safe to use? Testing in a pipeline exists to answer that

5 min
9-2

Why Unit Tests Belong at the Front of Your Pipeline

Imagine you push a code change on Friday afternoon. The build passes, the deployment goes through, and you head home. On Saturday morning, your phone

6 min
9-3

Integration Tests: Catching Problems When Components Talk to Each Other

You wrote a function that looks correct. The unit test passes. The logic is clean. Then you deploy it, and the application starts returning errors. The

5 min
9-4

Contract Testing: Catching Broken API Promises Before They Reach Production

You deploy a change to your user service. All tests pass. The pipeline is green. Five minutes later, the notification service starts throwing errors in

5 min
9-5

End-to-End Tests: When They Help and When They Just Slow You Down

You have unit tests checking every function. Integration tests verifying database queries. Contract tests making sure your API agreements hold. The

5 min
9-6

Smoke Tests and Synthetic Transactions: Verifying Your Deployment Actually Works

You just watched your pipeline turn green. Unit tests passed, integration tests passed, even the end-to-end tests came back clean. You hit deploy, the

6 min
9-7

Where Should Each Test Run in Your Pipeline?

You push code and wait. Five minutes pass. Ten minutes. The pipeline is still running. Finally, it fails -- but the error is from a unit test that should

5 min
9-8

When Your Pipeline Decides: Using Test Results as Evidence

You push your code, the pipeline starts, and you wait. Minutes later, a notification pops up: "Pipeline failed." You open the report, scroll through logs

5 min