On Fri, Mar 13, 2020 at 05:54:57PM -0700, Jakub Kicinski wrote:
Note that we loose a little bit of type safety without passing parameters as an explicit argument. If user puts the name of the wrong fixture as argument to CURRENT_FIXTURE() it will happily cast the type.
This got me to take a much closer look at things. I really didn't like needing to repeat the fixture name in CURRENT_FIXTURE() calls, and then started coming to all the same conclusions you did in your v1, that I just didn't quite see yet in my first review. :P
Apologies for my wishy-washy-ness on this, but here's me talking myself out of my earlier criticisms:
- "I want tests to be run in declaration order" In v1, this is actually mostly retained: they're still in declaration order, but they're grouped by fixture (which are run in declaration order). That, I think, is totally fine. Someone writing code that interleaves between fixtures is madness, and having the report retain that ordering seems awful. I had thought the declaration ordering was entirely removed, but I see on closer inspection that's not true.
- "I'd like everything attached to _metadata" This results in the type unsafety you call out here. And I stared at your v2 trying to find a way around it, but to get the type attached, it has to be part of the __TEST_F_IMPL() glue, and that means passing it along side "self", which means plumbing it as a function argument everywhere.
So, again, sorry for asking to iterate on v1 instead of v2, though the v2 _really_ helped me see the problems better. ;)
Something I'd like for v3: instead of "parameters" can we call it "instances"? It provides a way to run separate instances of the same fixtures. Those instances have parameters (i.e. struct fields), so I'd prefer the "instance" naming.
Also a change in reporting:
struct __fixture_params_metadata no_param = { .name = "", };
Let's make ".name = NULL" here, and then we can detect instantiation:
printf("[ RUN ] %s%s%s.%s\n", f->name, p->name ? "." : "", p->name ?: "", t->name);
That'll give us single-instance fixtures an unchanged name:
fixture.test1 fixture.test2
and instanced fixtures will be:
fixture.wayA.test1 fixture.wayA.test2 fixture.wayB.test1 fixture.wayB.test2
And finally, since we're in the land of endless macros, I think it could be possible to make a macro to generate the __register_foo() routine bodies. By the end of the series there are three nearly identical functions in the harness for __register_test(), __register_fixture(), and __register_fixture_instance(). Something like this as an earlier patch to refactor the __register_test() that can be used by the latter two in their patches (and counting will likely need to be refactored earlier too):
#define __LIST_APPEND(head, item) \ { \ /* Circular linked list where only prev is circular. */ \ if (head == NULL) { \ head = item; \ item->next = NULL; \ item->prev = item; \ return; \ } \ if (__constructor_order == _CONSTRUCTOR_ORDER_FORWARD) {\ item->next = NULL; \ item->prev = head->prev; \ item->prev->next = item; \ head->prev = item; \ } else { \ p->next = head; \ p->next->prev = item; \ p->prev = item; \ head = item; \ } \ }
Which should let it be used, ultimately, as:
static inline void __register_test(struct __test_metadata *t) __LIST_APPEND(__test_list, t)
static inline void __register_fixture(struct __fixture_metadata *f) __LIST_APPEND(__fixture_list, f)
static inline void __register_fixture_instance(struct __fixture_metadata *f, struct __fixture_instance_metadata *p) __LIST_APPEND(f->instances, p)
Thanks for working on this!
-Kees