23 lines
996 B
Markdown
23 lines
996 B
Markdown
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---
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title: >
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Write the test backwards
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pubDate: 2023-04-27
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permalink: >-
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archive/2023/04/27/tdd-write-the-test-backwards
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tags:
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- automated-testing
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- test-driven-development
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---
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When writing a test, something that I like to do is start by writing the first assertion first, and then work backwards.
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My first assertion might be `self::assertTrue($result)`.
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If I ran this test, it would fail because of the undefined `$result` variable - but it's clear to me what I need next by asking, "Where does `$result` come from?".
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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?".
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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.
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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.
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