> I don't think everything needs a comprehensive set of unit tests though.

There's a difference in the tests of that era though. Around the xp times, unit tests were for unit of functionality, not per-method.

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caseyohara 4 days ago | parent | next [-]

That’s not really true.

“Unit tests are small tests, each one exercising a little piece of functionality. The units tested are usually individual methods, but sometimes clusters of methods or even whole objects.”

Extreme Programming Explained: Embrace Change, 2nd Edition (2004) Kent Beck

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viraptor 3 days ago | parent | next [-]

You're agreeing with me there. "each one exercising a little piece of functionality". In Beck's approach the tests are added at each step for a simple functionality addition, which then gets implemented in the project to pass the test. These days unit tests are more commonly used as "every method is a unit to be tested completely", often after the implementation is already there.

	▲	caseyohara 2 days ago \| parent [-]
		I don’t see how? You said: “Around the xp times, unit tests were not per-method.” Beck said: “Unit tests are usually individual methods”

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Izkata 4 days ago | parent | prev [-]

That quote is saying the same thing as GP.

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anonymars 4 days ago | parent | prev | next [-]

I also wonder if this is written from a statically-typed perspective. In dynamic-typing land there are so many more stupid little things that can break that the compiler would otherwise catch for you

Either that or tracing/logging/debugging, but other than specific niches like parsing (of specific bug repros) I think integration tests are generally a lot more bang for the buck.

Anyway, if you want to go down a related-but-unrelated rabbit hole, J.R. Thompson's lecture on the Space Shuttle Main Engines is a good one. You can probably watch it at higher speed to smooth out the many, many "uh"s (believe me, it's bad):

Integrated testing: https://youtu.be/uow6v1EuybE?t=1292

Test to failure: https://youtu.be/uow6v1EuybE?t=3135

https://ocw.mit.edu/courses/16-885j-aircraft-systems-enginee...

There's this more-modern link but in true modern fashion you can't really link to specific things presumably because it's all javascript muck: https://openlearninglibrary.mit.edu/courses/course-v1:MITx+1...

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ffk 4 days ago | parent | prev [-]

I think a more accurate version of this is: unit tests were not only per-method but also per functionality. This was often called BDD (Behavior Driven Development), e.g. Ruby's cucumber. Your intuition here is correct though.

	▲	viraptor 3 days ago \| parent [-]
		I disagree with the "not only". The idea in xp is to write the test first. http://www.extremeprogramming.org/rules/testfirst.html You don't know how many methods/functions (if any) you're going to add to make it pass, so they're explicitly per-functionality.