bug#69714: 30.0.50; ert-font-lock doesn't handle list of faces

[Vladimir Kazanov]

Hi,

Thanks for reporting this! I have a bunch of ert-font-lock
improvements in my local repo getting ready for submission, and can
look into your suggestions as well.

Do you have your unit test code somewhere in a public repo? It'd be
great to think of further improvements to support your use case.

Thanks,
Vlad

On Sun, 10 Mar 2024 at 20:33, Troy Brown <brownts@troybrown.dev> wrote:
>
> I'm trying to use this package to test out my tree-sitter mode, but am
> running into an issue with lists of faces.  It's possible that the
> face for a location in the buffer will contain a list of 1 or more
> faces.  For example, when I use the ":override 'prepend" keyword in
> the call to treesit-font-lock-rules, even if only a single face is
> specified for the rule that matches that section of the buffer, this
> will result in a list of one entry (i.e., "(face-name)").
>
> When this happens, ert-font-lock fails to recognize that this matches
> the face "face-name" (e.g., "^ face-name" will fail to match in this
> case).  I feel the tool should recognize a list containing a single
> face as matching the face.  Even worse however, it appears
> ert-font-lock doesn't support a list of faces in the comment.  I tried
> to work around the original issue by using "^ (face-name)", but the
> tool silently ignores this, as it doesn't match the internal regular
> expression (which ended up allowing my test to pass without actually
> checking anything).
>
> I can't figure out a way to use this tool in its current state due to
> its lack of support for a list of faces.  Also, I find that since it
> silently ignores incorrect comment syntax (e.g., "^face-name", "^
> (face-name)"), it gives a false illusion that it's actually performing
> those checks (and the checks are passing), when it's really just
> ignoring them.  Maybe any comment line starting with a "^" or "<-"
> should be considered an assertion check and to fail if the rest of the
> syntax is not as expected.  Maybe it should also fail the test if no
> assertion checks are found in a source file or string.
>
> Even if the tool would allow a list of a single face to match the
> supplied face in the comment, I think it should also allow for
> multiple faces to be listed in the comment.  I have other places where
> multiple faces are used (e.g., "(font-lock-constant-face
> font-lock-variable-name-face)" to highlight a constant variable),
> which would not be testable with the current state of the package.
>
>
>


-- 
Regards,

Vladimir Kazanov