run-tests-on-the-unmodified-codebase-before-starting-to-establis

Running the full test suite on the unmodified codebase before modifying any code captures all pre-existing test failures. This documented baseline clearly distinguishes new bugs introduced by your changes from issues that already existed.

Running tests on the unmodified codebase first prevents misattribution of post-change test failures to pre-existing issues. This approach captures a documented baseline of existing failures, reducing debugging overhead and improving change validation accuracy.

Executing a full test run on the unmodified codebase before implementing modifications documents all existing test failures. This creates a verifiable pre-change test baseline for accurate failure attribution during later code change validation.

Pre-change testing applies to all software development workflows involving code changes, bug fixes, and feature additions. Running the full test suite beforehand ensures accurate test failure attribution across any type of code modification workflow.

You need to capture a pre-change test failure baseline whenever implementing a new feature or fixing a bug. Documenting which tests were already failing on the unmodified codebase ensures you do not waste time investigating issues you did not cause.