“Happy path testing” isn’t really testing at all. Following the “happy path” is a demonstration.
Here’s the role demonstration plays in testing: it’s nice to know that your product can achieve the happy path before you start to test it. To the degree a demonstration is a test, it’s a very shallow test.
If you’re building something new and non-trivial that matters to people, or that could harm people, there’s a risk that you might not entirely understand it or what it affects. To develop your understanding, you’ll probably want to test it; to learn about it; to investigate it; to interact with it directly; to probe it with tools; to stress it out. You’ll probably want to explore it and experiment with it; to evaluate it. That’s testing.
If you can’t even achieve the happy path, you’re not ready for testing.
Related posts:
Finding the Happy Path
Testing and Checking Refined
Why Checking is Not Enough
Acceptance Tests: Let’s Change the Title, Too
More of What Testers Find
Why We Do Scenario Testing
Until we sufficiently learned about the users, the product, and the environment, we have no idea what usage pattern is a “happy path” and what would be the “edge cases”.
My thoughts and real life examples here: http://automation-beyond.com/2017/05/02/alternative-facts-happy-path-and-edge-cases/
Michael replies: This is an important point, and one worthy of a blog post. I’ll get on it!