RFC: Consolidate test rootfs in single place

[evelikov]

This series started off as de-duplicating the macros that we copy-paste across the tests and ultimately paved the way to allowing the tests to run in a VM aka #50.

That goal is not yet complete, but the general premise is that:

• DEFINE_TEST provides the rootfs (just the test sub-folder) and uname
• any files (output.out, output.err, output.files) are stored and defined as relative to ^^
  • some tests are currently bugged wrt ^^
• path construction - be that for output or the TESTSUITE_ROOTFS happens in the shared places - testsuite.c and/or path.c
• (to be added as follow-up PR) machinery will copy/mount the sub-test folder into a chroot-like setup and run the test

As you can see the patch series isn't even complete yet. Although since it's churn heavy I thought that sending it out early to feedback, would be a good idea.

Aside: I have another 1-2 series to further reduce the boilerplate, following which the tests will start to flow 🤞

[evelikov]

If people are happy with the way things are going, we can land all the patches but the (obviously incomplete) fifth one. Thus we don't have to boil the ocean in one go - aka we don't have to fix everything in this one PR.

[evelikov]

We could even change the string options output.out and output.err to bool, where the filename is a well-known/consistent one. Thus further reducing boilerplate and having consistent experience across tests.

For example we currently have a dozen or so instances of correct.txt and another dozen of correct-foobar.txt for the stdout expectations. With the per sub-directory approach, the need for different filenames will disappear.

Let me know what you think o/

[evelikov]

Pondering a bit, I'm inclined to have v2 roughly as follows. Let me know if anything seems amiss.

DEFINE_TEST(foobar,
	.description = "something",
	.config = {
		[TC_UNAME_R] = MODULES_UNAME,
		[TC_ROOTFS] = ROOBAR_ROOTFS,
	},
	.output = {
		.out = ROOBAR_ROOTFS "/correct.txt",
		.files = (const struct keyval[]) {
			{ ROOBAR_ROOTFS "/correct-modules.alias",
			  ROOBAR_ROOTFS "/modules.alias" },
			{ },
		},
	});

DEFINE_TEST(foobar,
	.description = "something",
	.config = {
		[TC_UNAME_R] = MODULES_UNAME,
		[TC_ROOTFS] = ROOBAR_ROOTFS,
	},
	.compare = {
                .stdout = true,
		.modules-alias = true, // or "alias" or another name really
	});

The comparison (aka correct) files will live in "$TC_ROOTFS/compare/" (stdout.txt stderr.txt, modules.alias etc). The test infra will preemptively fail if a) the bool is set yet file is missing or b) when file is present but bool is false.

[lucasdemarchi]

@evelikov that new format looks good. Maybe also keep a files[] in that compare struct for the one-off cases?

.compare = {
        .files = { "/foo/bar/modules.alias", "/foor/bar/modules.dep" },
}

... which expects the same file to be present in $TC_ROOTFS/compare/

[lucasdemarchi]

I picked the first commit, "testsuite/test-weakdep: remove custom handling".