Excerpts from Sébastien Hinderer's message of 2017-10-30 16:39:24 +0100:
Dear Edward,
Many thanks for your prompt response!
Edward Z. Yang (2017/10/30 11:25 -0400):
Actually, it's the reverse of what you said: like OCaml, GHC essentially has ~no unit tests; it's entirely Haskell programs which we compile (and sometimes run; a lot of tests are for the typechecker only so we don't bother running those.) The .T file is just a way of letting the Python driver know what tests exist.
Oh okay! Would you be able to point me to just a few tests to get an idea of a few typical situations, please?
For example: The metadata https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail... The source file https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail... The expected error output https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail...
One other question I forgot to ask: how do you deal with conditional tests? For instance, if a test should be run only on some platforms? Or, in OCaml we have tests for Fortran bindings that should be run only if a Fortran compiler is available. How would you deal with such tests?
All managed inside the Python driver code. Example: https://github.com/ghc/ghc/blob/master/testsuite/tests/rts/all.T#L32 Edward