daily-email: add 2023-09-30

Automated testing offers repeatability

src/content/daily-email/2023-09-30.md

@@ -0,0 +1,34 @@
+---
+title: >
+  Automated testing offers repeatability
+pubDate: 2023-09-30
+permalink: >
+  archive/2023/09/30/automated-testing-offers-repeatability
+tags:
+  - automated-testing
+  - test-driven-development
+---
+
+You work on feature or bug fix.
+
+It gets tested manually by you, a tester, and the person who requested the feature or reported the bug.
+
+It may get tested on multiple environments.
+
+It passes and it moved to production.
+
+But now it's live, it's not tested again.
+
+Although it works now, there's no guarantee it's not broken or regressed by subsequent changes.
+
+It's definitely not tested manually before every future release.
+
+## Here's the thing
+
+Automated testing offers repeatability.
+
+The tests pass, so the functionality works when you wrote it, and you can re-check it by re-running the test.
+
+The test suite can be run by Developers whilst working on other changes, before code review and before deployments.
+
+The test suite can be run automatically in a CI pipeline for every change that's pushed, and you'll know your change not only worked at the time but will continue to work.