On 2023.06.30 15:07, Phillip Wood wrote: > Hi Josh > > Thanks for putting this together, I think it is really helpful to have a > comparison of the various options. Sorry for the slow reply, I was off the > list for a couple of weeks. Thank you for the review! Unfortunately I didn't see it in time for any of these to make it into v4, but I'll keep them all as TODOs. > On 10/06/2023 00:25, Josh Steadmon wrote: > > diff --git a/Documentation/technical/unit-tests.txt b/Documentation/technical/unit-tests.txt > > new file mode 100644 > > index 0000000000..dac8062a43 > > --- /dev/null > > +++ b/Documentation/technical/unit-tests.txt > > +== Definitions > > + > > +For the purposes of this document, we'll use *test framework* to refer to > > +projects that support writing test cases and running tests within the context > > +of a single executable. *Test harness* will refer to projects that manage > > +running multiple executables (each of which may contain multiple test cases) and > > +aggregating their results. > > Thanks for adding this, it is really helpful to have definitions for what we > mean by "test framework" and "test harness" within the git project. It might > be worth mentioning somewhere that we already use prove as a test harness > when running our integration tests. Yeah, I'll try to clarify this, probably not in V4 though. I'll note it as a remaining TODO. > > +==== Parallel execution > > + > > +Ideally, we will build up a significant collection of unit tests cases, most > > +likely split across multiple executables. It will be necessary to run these > > +tests in parallel to enable fast develop-test-debug cycles. > > This is a good point, though I think it is really a property of the harness > rather than the framework so we might want to indicate in the table whether > a framework provides parallelism itself or relies on the harness providing > it. Same here. > > [...] > > +==== Major platform support > > + > > +At a bare minimum, unit-testing must work on Linux, MacOS, and Windows. > > I think we'd want to be able to run unit tests on *BSD and NonStop as well, > especially as I think some of the platform dependent code probably lends > itself to being unit tested. I suspect a framework that covers Linux and > MacOS would probably run on those platforms as well (I don't think NonStop > has complete POSIX support but it is hard to imagine a test framework doing > anything very exotic) Yes, unfortunately I don't have easy access to either of these, but I'll try to figure out how to evaluate these. > > [...] > > +==== Mock support > > + > > +Unit test authors may wish to test code that interacts with objects that may be > > +inconvenient to handle in a test (e.g. interacting with a network service). > > +Mocking allows test authors to provide a fake implementation of these objects > > +for more convenient tests. > > Do we have any idea what sort of thing we're likely to want to mock and what > we want that support to look like? Not at the moment. Another TODO for v5. > > +==== Signal & exception handling > > + > > +The test framework must fail gracefully when test cases are themselves buggy or > > +when they are interrupted by signals during runtime. > > I had assumed that it would be enough for the test harness to detect if a > test executable was killed by a signal or exited early due to a bug in the > test script. That requires the framework to have robust support for lazy > test plans but I'm not sure that we need it to catch and recover from things > like SIGSEGV. I think as long as a SIGSEGV in the test code doesn't cause the entire test run to crash, we'll be OK. Agreed that this is really more of a harness feature. > > +==== Coverage reports > > + > > +It may be convenient to generate coverage reports when running unit tests > > +(although it may be possible to accomplish this regardless of test framework / > > +harness support). > > I agree this would be useful, though perhaps we should build it on our > existing gcov usage. > > Related to this do we want timing reports from the harness or the framework? I'll add this as well in V5. > > + > > +=== Comparison > > + > > +[format="csv",options="header",width="75%"] > > +|===== > > +Framework,"TAP support","Diagnostic output","Parallel execution","Vendorable / ubiquitous","Maintainable / extensible","Major platform support","Lazy test planning","Runtime- skippable tests","Scheduling / re-running",Mocks,"Signal & exception handling","Coverage reports" > > +https://lore.kernel.org/git/c902a166-98ce-afba-93f2-ea6027557176@xxxxxxxxx/[Custom Git impl.],[lime-background]#True#,[lime-background]#True#,?,[lime-background]#True#,[lime-background]#True#,[lime-background]#True#,[lime-background]#True#,?,?,[red-background]#False#,?,? > > +https://cmocka.org/[cmocka],[lime-background]#True#,[lime-background]#True#,?,[red-background]#False#,[yellow-background]#Partial#,[yellow-background]#Partial#,[yellow-background]#Partial#,?,?,[lime-background]#True#,?,? > > +https://libcheck.github.io/check/[Check],[lime-background]#True#,[lime-background]#True#,?,[red-background]#False#,[yellow-background]#Partial#,[lime-background]#True#,[yellow-background]#Partial#,?,?,[red-background]#False#,?,? > > +https://github.com/rra/c-tap-harness/[C TAP],[lime-background]#True#,[red-background]#False#,?,[lime-background]#True#,[yellow-background]#Partial#,[yellow-background]#Partial#,[yellow-background]#Partial#,?,?,[red-background]#False#,?,? > > +https://github.com/silentbicycle/greatest[Greatest],[yellow-background]#Partial#,?,?,[lime-background]#True#,[yellow-background]#Partial#,?,[yellow-background]#Partial#,?,?,[red-background]#False#,?,? > > +https://github.com/Snaipe/Criterion[Criterion],[lime-background]#True#,?,?,[red-background]#False#,?,[lime-background]#True#,?,?,?,[red-background]#False#,?,? > > +https://github.com/zorgnax/libtap[libtap],[lime-background]#True#,?,?,?,?,?,?,?,?,?,?,? > > +https://nemequ.github.io/munit/[µnit],?,?,?,?,?,?,?,?,?,?,?,? > > +https://github.com/google/cmockery[cmockery],?,?,?,?,?,?,?,?,?,[lime-background]#True#,?,? > > +https://github.com/lpabon/cmockery2[cmockery2],?,?,?,?,?,?,?,?,?,[lime-background]#True#,?,? > > +https://github.com/ThrowTheSwitch/Unity[Unity],?,?,?,?,?,?,?,?,?,?,?,? > > +https://github.com/siu/minunit[minunit],?,?,?,?,?,?,?,?,?,?,?,? > > +https://cunit.sourceforge.net/[CUnit],?,?,?,?,?,?,?,?,?,?,?,? > > +https://www.kindahl.net/mytap/doc/index.html[MyTAP],[lime-background]#True#,?,?,?,?,?,?,?,?,?,?,? > > +|===== > > Thanks for going through these projects, hopefully we can use this > information to make a decision on a framework soon. > > Best Wishes > > Phillip
