Tests can assert multiple things

Similar to "a method should only have one return statement", I've seen similar advice when working with tests: "Tests should only have a single assertion".

I don't think this is true, and in my experience, you need multiple assertions to have a thorough test.

And, whilst similar assertions add some duplication, they can make the intent clearer and give better error messages.

Instead, I focus on one test case per test.

If I'm testing the following:

  • A blog page exists.
  • Only post nodes are visible.
  • Only published posts are visible,
  • Posts are returned in a specified order.

These will be split into separate tests - making it easier to read and maintain the code and have faster execution times by running only the tests I want with the minimum amount of code in each - regardless of how many assertions are in each.

- Oliver

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About me

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I'm an Acquia-certified Drupal Triple Expert with 17 years of experience, an open-source software maintainer and Drupal core contributor, public speaker, live streamer, and host of the Beyond Blocks podcast.