[NikitaNazarov1]

#875 asks for a hook that copies a ticket ID from a branch such as task/PROJ-123/fix-login into the commit message as [PROJ-123] . ReplaceBranch can already do this with branch_pattern and replacement_text. But with the default skipped_commit_types, it runs only for editor commits. When you remove message or commit from that list, the hook adds a second prefix to git commit -m '[PROJ-123] Fix' and to git commit --amend. It also prefixes git commit --fixup, so the subject no longer starts with fixup! and git rebase --autosquash does not find the commit.

Leave the message unchanged when it already starts with the replacement text, or with fixup! , squash! , or amend! . The comparison ignores surrounding whitespace, so [PROJ-123]Fix also counts. A template that ends in a word character must end at a word boundary: PROJ-12 does not match PROJ-123 Fix. The comparison uses bytes, because lstrip raises on a message that is not valid in the default encoding, such as an amended Latin-1 commit, and that would stop the commit. A whitespace-only replacement text is still prepended as before.

The default configuration does not change: it runs the hook only for editor commits, whose message file starts with a blank line and Git comments.

Document a ticket ID configuration in the hook's class comment. It keeps template skipped, because a commit template can start with a # line, and the prefix would turn that comment into the subject. It sets on_warn: pass, so branches without a ticket ID do not show a warning.

Follow-up to #875, where a PR with a configurable hook was invited.

Validation: bundle exec ruby script/parallel_rspec.rb passes all 1884 examples, and RuboCop reports no offenses on the changed files. 8 of the new ReplaceBranch examples fail against main. The others pin behavior that must not change: a longer ticket ID, a whitespace-only template, and a message that is not valid UTF-8. I also ran the documented configuration in a disposable repository with Git 2.50.1:

• commit -m 'Fix login' gives [PROJ-123] Fix login.
• --amend -m '[PROJ-123] Fix login form' and --amend --no-edit keep one prefix.
• --fixup=HEAD gives fixup! [PROJ-123] Fix login form.
• A Latin-1 commit -F and its amend, under a UTF-8 locale, give [PROJ-123] Änderung am Login.
• A commit on main stays unchanged and shows no warning.

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