Regression Testing: Stop Old Bugs Coming Back

Regression testing is re-checking software that used to work, after a change, to confirm it still works. Every fix, feature or library upgrade can quietly break something three screens away. A regression suite is your safety net: a known set of checks you run before each release so old bugs stay dead.

Why regressions happen in the first place

Code is connected in ways nobody fully remembers. A developer tightens a validation rule on the signup form, and the admin "invite user" flow, which reuses the same model, starts rejecting valid emails. Nobody touched the invite screen, so nobody thought to test it.

Common triggers:

• Bug fixes that change shared code paths
• Refactors that "shouldn't change behaviour"
• Library or framework upgrades
• Configuration differences between environments
• Hotfixes rushed out without the usual checks

The pattern is always the same: the change was tested, its neighbours were not.

What belongs in a regression suite

You can't retest everything every time, and you shouldn't try. A useful suite is deliberately selective.

1. Business-critical flows. Sign-in, checkout, data export — whatever would cause a support storm if it broke.
2. Previously fixed bugs. If a defect escaped once, add a check for it. Bugs that came back once tend to come back again.
3. High-churn areas. Modules that change every sprint deserve more coverage than stable ones.
4. Integration seams. Anywhere your app talks to another system, a payment provider or an identity service.

Automate the stable, repetitive checks where you can. Keep manual regression for flows where judgement matters: layouts, copy, and the "does this still feel right" checks a script won't catch.

Need proof your work was tested? See how Flow records test runs and sign-off as evidence. Get started with Flow →

When to run it

Tie regression testing to your release rhythm, not to someone remembering. A sensible pattern for most teams:

• A short smoke pass after every deploy to a test environment
• The full regression run before a release goes to production
• A targeted run around any hotfix, covering the fixed area and its neighbours

Make the run a line item on your release checklist so it can't be skipped when the deadline is tight, which is exactly when it matters most.

Keeping the suite lean

Suites rot. Checks get added and never removed, until a full run takes two days and people quietly start skipping it.

Review the suite every few releases. Retire checks for features that no longer exist, merge duplicates, and give more attention to areas that keep failing. A suite people actually run beats a perfect suite people avoid.

How Flow helps

Plenty of teams use TestRail, a dedicated test-management tool with deep test-case libraries and reporting. It's a strong choice if you want QA in its own product. If you'd rather keep testing next to the tickets and releases it relates to, Livex Flow builds it into the delivery platform:

• Test runs on real tickets. The test-run wizard lets you choose a project, the tickets to cover and the testers, then start, pause and complete the run with time recorded.
• Failure history per ticket. Each ticket is marked pass or fail, and its failure history shows which areas keep regressing, so you know what to include next time.
• Issues logged in context. Testers log issues with attachments, and drafts auto-save, so nothing is lost halfway through a run.
• Release steps that persist. Add "full regression run complete" to a release checklist; progress is kept if you pause and come back later.

For the mechanics of setting one up, see how to plan and run a test run.