Your CI Pipeline Passed. Your Integration Tests Didn’t Catch the Bug.

Everything was green.

The PR was approved. Unit tests passed. Integration tests passed. The CI pipeline was successful.

So we merged the code.

A few minutes later, something broke.

The problem wasn’t that we had no tests.

We had tests. We were just testing the wrong things.

A green CI pipeline gives confidence, but it doesn’t guarantee that your application will behave correctly in production.

The real question is:

Are our tests actually testing the scenarios that can fail in production?

Let’s see where things can go wrong.

The CI Pipeline Was Green

Imagine a typical Spring Boot project.

A developer pushes code:

Developer
    |
    | git push
    v
Git Repository
    |
    v
CI Pipeline
    |
    +---- Compile
    |
    +---- Unit Tests
    |
    +---- Integration Tests
    |
    +---- Code Coverage
    |
    +---- Build
    |
    v
   PASS

Everything looks good.

A simplified Jenkins pipeline might look like:

Checkout Code
      |…