Add daily email for 2025-02-03

Good software is easy to test

source/_daily_emails/2025-02-03.md

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+---
+title: Good software is easy to test
+date: 2025-02-03
+permalink: daily/2025/02/03/testable
+tags:
+  - software-development
+  - testing
+cta: testing_course
+snippet: |
+  Good software is easy to write automated tests for.
+---
+
+One piece of criteria for whether some software is good is whether it's easy to write automated tests for.
+
+I recently worked on a method that was more than 150 lines.
+
+It was difficult to understand, had too many responsibilities and didn't use dependency injection.
+
+This made it difficult to test.
+
+If it was split into several smaller methods or classes, each could be responsible for different aspects and have clear responsibilities.
+
+Each new method or class could have its own tests to verify its own functionality works.
+
+It would be easy to understand and identify and fix any issues.
+
+If dependency injection was used, things can be mocked or changed as needed to make the logic testable.
+
+If everything is in one large function, the code isn't testable.
+
+Even if it works now, it will be difficult to change in the future.