daily-email: add 2023-04-27

src/content/daily-email/2023-04-27.md

@@ -0,0 +1,22 @@
+---
+title: >
+  TDD: write the test backwards
+pubDate: 2023-04-27
+permalink: >
+  archive/2023/04/27/tdd-write-the-test-backwards
+tags:
+  - automated-testing
+  - test-driven-development
+---
+
+When writing a test, something that I like to do is start by writing the first assertion first, and then work backwards.
+
+My first assertion might be `self::assertTrue($result)`.
+
+If I ran this test, it would fail because of the undefined `$result` variable - but it's clear to me what I need next by asking, "Where does `$result` come from?".
+
+If I need to call a method on another class and get the result, I'll add it before the assertion. Then I repeat the process and ask, "What do I need for this to work?".
+
+Maybe I need to create some users or content in the application for the class to query and return a result based on it, so I'll create those.
+
+With this approach, I'm not making any assumptions about the test's prerequisites, and I usually find that I end up with cleaner and more focused tests.