Re: [PATCH v6 01/18] kunit: test: add KUnit test runner core

[Brendan Higgins]

On Mon, Jul 8, 2019 at 11:08 AM Brendan Higgins
<brendanhiggins@xxxxxxxxxx> wrote:
>
> On Fri, Jul 5, 2019 at 1:15 PM Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote:
> >
> > On Wed, Jul 03, 2019 at 05:35:58PM -0700, Brendan Higgins wrote:
> > > Add core facilities for defining unit tests; this provides a common way
> > > to define test cases, functions that execute code which is under test
> > > and determine whether the code under test behaves as expected; this also
> > > provides a way to group together related test cases in test suites (here
> > > we call them test_modules).
> > >
> > > Just define test cases and how to execute them for now; setting
> > > expectations on code will be defined later.
> > >
> > > Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> > > Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> >
> > Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> >
> > But a nitpick below, I think that can be fixed later with a follow up
> > patch.
> >
> > > +/**
> > > + * struct kunit - represents a running instance of a test.
> > > + * @priv: for user to store arbitrary data. Commonly used to pass data created
> > > + * in the init function (see &struct kunit_suite).
> > > + *
> > > + * Used to store information about the current context under which the test is
> > > + * running. Most of this data is private and should only be accessed indirectly
> > > + * via public functions; the one exception is @priv which can be used by the
> > > + * test writer to store arbitrary data.
> > > + *
> > > + * A brief note on locking:
> > > + *
> > > + * First off, we need to lock because in certain cases a user may want to use an
> > > + * expectation in a thread other than the thread that the test case is running
> > > + * in.
> >
> > This as a prefix to the struct without a lock seems odd. It would be
> > clearer I think if you'd explain here what locking mechanism we decided
> > to use and why it suffices today.
>
> Whoops, sorry this should have been in the next patch. Will fix.

Err..no, this shouldn't be here at all. Sorry about that. I just need
to rewrite the comment.

> > > +/**
> > > + * suite_test() - used to register a &struct kunit_suite with KUnit.
> >
> > You mean kunit_test_suite()?
>
> Yep, sorry about that. Will fix.
>
> > > + * @suite: a statically allocated &struct kunit_suite.
> > > + *
> > > + * Registers @suite with the test framework. See &struct kunit_suite for more
> > > + * information.
> > > + *
> > > + * NOTE: Currently KUnit tests are all run as late_initcalls; this means that
> > > + * they cannot test anything where tests must run at a different init phase. One
> > > + * significant restriction resulting from this is that KUnit cannot reliably
> > > + * test anything that is initialize in the late_init phase.
> >                             initialize prior to the late init phase.
> >
> >
> > That is, this is useless to test things running early.
>
> Yeah, I can add that phrasing in.
>
> > > + *
> > > + * TODO(brendanhiggins@xxxxxxxxxx): Don't run all KUnit tests as late_initcalls.
> > > + * I have some future work planned to dispatch all KUnit tests from the same
> > > + * place, and at the very least to do so after everything else is definitely
> > > + * initialized.
> >
> > TODOs are odd to be adding to documentation, this is just not common
> > place practice. The NOTE should suffice for you.
>
> Because it is a kernel doc? Would you usually make a separate
> non-kernel doc comment for a TODO? I guess that makes sense.
>
> Thanks!