Integration tests are as old as unit tests, and both predate their names. When exactly were unit tests made redundant? I don't see the point of your quip without a trace of actual argument.

I feel like I don't write enough tests, and when I do they're usually integration tests, but some things - algorithms, complex but pure functions, data structures - absolutely deserve their unit tests that can't be reasonably replaced by integration/e2e tests.

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s_ting765 6 days ago | parent [-]

Here's the argument backing up my claim.

Unit tests don't matter when you have other types of testing like functional or integration testing that will tell you whether your code has the intended behavior and effect when run.

In the above statement unit tests is also considered as code.

That's where the redundancy comes from.

	▲	skydhash 6 days ago \| parent [-]
		Unit tests do matter, especially when the logic is somewhat complex or very defined (splitting money, parsing some message). So unless the specs change, you rarely have to modify the tests. So it helps more in a technical sense, catching developer mistakes. Just like qa tests on some small part of the car can spot defect early on. Integrated tests is more about ensuring what matters to Product. A car that refuses to start is worthless for most cases. But the engine light and a window that can’t open is not usually a dealbreaker. Unit tests can help pinpoint an issue or ensure that a specs is implemented. But that’s mostly relevant to the developer world. So for a proper DX, add unit tests to help pinpoint bugs faster, especially with code that doesn’t change as much and where knowledge can be lost.