[libcamera-devel] [PATCH v2] utils: checkstyle.py: Add commit title checker

[Jacopo Mondi]

I don't really understand python but it seems ok to me

Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

On Thu, Dec 22, 2022 at 12:12:37AM +0200, Laurent Pinchart via libcamera-devel wrote:
> Add a commit checker to ensure that commit titles start with a prefix.
> The commit issue message lists prefix candidates retrieved from the git
> log.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
>
> - Reduce indentation
> ---
>  utils/checkstyle.py | 62 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 62 insertions(+)
>
> diff --git a/utils/checkstyle.py b/utils/checkstyle.py
> index a11d95cc5808..364e13d6533d 100755
> --- a/utils/checkstyle.py
> +++ b/utils/checkstyle.py
> @@ -352,6 +352,68 @@ class HeaderAddChecker(CommitChecker):
>          return issues
>
>
> +class TitleChecker(CommitChecker):
> +    prefix_regex = re.compile(r'[0-9a-f]+ (([a-zA-Z0-9_.-]+: )+)')
> +    release_regex = re.compile(r'libcamera v[0-9]+\.[0-9]+\.[0-9]+')
> +
> +    @classmethod
> +    def check(cls, commit, top_level):
> +        title = commit.title
> +
> +        # Ignore release commits, they don't need a prefix.
> +        if TitleChecker.release_regex.fullmatch(title):
> +            return []
> +
> +        prefix_pos = title.find(': ')
> +        if prefix_pos != -1 and prefix_pos != len(title) - 2:
> +            return []
> +
> +        # Find prefix candidates by searching the git history
> +        msgs = subprocess.run(['git', 'log', '--no-decorate', '--oneline', '-n100', '--'] + commit.files(),
> +                              stdout=subprocess.PIPE).stdout.decode('utf-8')
> +        prefixes = {}
> +        prefixes_count = 0
> +        for msg in msgs.splitlines():
> +            prefix = TitleChecker.prefix_regex.match(msg)
> +            if not prefix:
> +                continue
> +
> +            prefix = prefix.group(1)
> +            if prefix in prefixes:
> +                prefixes[prefix] += 1
> +            else:
> +                prefixes[prefix] = 1
> +
> +            prefixes_count += 1
> +
> +        if not prefixes:
> +            return [CommitIssue('Commit title is missing prefix')]
> +
> +        # Sort the candidates by number of occurrences and pick the best ones.
> +        # When multiple prefixes are possible without a clear winner, we want to
> +        # display the most common options to the user, but without the most
> +        # unlikely options to avoid too long messages. As a heuristic, select
> +        # enough candidates to cover at least 2/3 of the possible prefixes, but
> +        # never more than 4 candidates.
> +        prefixes = list(prefixes.items())
> +        prefixes.sort(key=lambda x: x[1], reverse=True)
> +
> +        candidates = []
> +        candidates_count = 0
> +        for prefix in prefixes:
> +            candidates.append(f"`{prefix[0]}'")
> +            candidates_count += prefix[1]
> +            if candidates_count >= prefixes_count * 2 / 3 or \
> +               len(candidates) == 4:
> +                break
> +
> +        candidates = candidates[:-2] + [' and '.join(candidates[-2:])]
> +        candidates = ', '.join(candidates)
> +
> +        return [CommitIssue('Commit title is missing prefix, '
> +                            'possible candidates are ' + candidates)]
> +
> +
>  # ------------------------------------------------------------------------------
>  # Style Checkers
>  #
>
> base-commit: f66a5c447b65bce774a1bc2d01034f437bf764b5
> prerequisite-patch-id: 55c457bf621237f99229898adb78e18b259ab74b
> --
> Regards,
>
> Laurent Pinchart
>