From 86d5ab84cb7b5b08259796b56ffb6d4e784f8980 Mon Sep 17 00:00:00 2001
From: Mariano Anaya <marianoanaya@gmail.com>
Date: Fri, 31 May 2024 13:08:20 +0200
Subject: [PATCH] New hook for enforcing branch name

Use a regex to validate the naming convention the branch should follow.
If it's not correct, it fails.
---
 .pre-commit-hooks.yaml                  |  7 +++++
 README.md                               | 12 ++++++++
 pre_commit_hooks/enforce_branch_name.py | 38 +++++++++++++++++++++++++
 setup.cfg                               |  1 +
 4 files changed, 58 insertions(+)
 create mode 100644 pre_commit_hooks/enforce_branch_name.py

diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
index 44a8648..026733c 100644
--- a/.pre-commit-hooks.yaml
+++ b/.pre-commit-hooks.yaml
@@ -204,3 +204,10 @@
     language: python
     types: [text]
     stages: [commit, push, manual]
+-   id: enforce-branch-name
+    name: enforce branch name
+    description: Make sure the current branch follows one of the accepted patterns.
+    entry: enforce-branch-name
+    language: python
+    pass_filenames: false
+    always_run: true
diff --git a/README.md b/README.md
index 97bfba6..cf67808 100644
--- a/README.md
+++ b/README.md
@@ -210,6 +210,18 @@ Trims trailing whitespace.
   - By default, this hook trims all whitespace from the ends of lines.
     To specify a custom set of characters to trim instead, use `args: [--chars,"<chars to trim>"]`.
 
+
+#### `enforce-branch-name`
+Validates the branch name follows a pattern.
+  - `-p` / `--pattern` is used to pass the regex a valid branch name should have.
+
+Note that `enforce-branch-name` is configured by default to [`always_run`](https://pre-commit.com/#config-always_run).
+As a result, it will ignore any setting of [`files`](https://pre-commit.com/#config-files),
+[`exclude`](https://pre-commit.com/#config-exclude), [`types`](https://pre-commit.com/#config-types)
+or [`exclude_types`](https://pre-commit.com/#config-exclude_types).
+Set [`always_run: false`](https://pre-commit.com/#config-always_run) to allow this hook to be skipped according to these
+file filters. Caveat: In this configuration, empty commits (`git commit --allow-empty`) would always be allowed by this hook.
+
 ### Deprecated / replaced hooks
 
 - `check-byte-order-marker`: instead use fix-byte-order-marker
diff --git a/pre_commit_hooks/enforce_branch_name.py b/pre_commit_hooks/enforce_branch_name.py
new file mode 100644
index 0000000..170e1c2
--- /dev/null
+++ b/pre_commit_hooks/enforce_branch_name.py
@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+import argparse
+import re
+from typing import AbstractSet
+from typing import Sequence
+
+from pre_commit_hooks.util import CalledProcessError
+from pre_commit_hooks.util import cmd_output
+
+OK = 0
+ERROR = 1
+
+
+def branch_follows_pattern(patterns: AbstractSet[str]) -> bool:
+    try:
+        ref_name = cmd_output("git", "symbolic-ref", "HEAD")
+    except CalledProcessError:
+        return False
+    chunks = ref_name.strip().split("/")
+    branch_name = "/".join(chunks[2:])
+    return any(re.match(p, branch_name) for p in patterns)
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "-p",
+        "--pattern",
+        action="append",
+        help=("regex pattern that the name of the branch must comply with"),
+    )
+    args = parser.parse_args(argv)
+    return OK if branch_follows_pattern(frozenset(args.pattern)) else ERROR
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/setup.cfg b/setup.cfg
index 82a5457..8045b40 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -63,6 +63,7 @@ console_scripts =
     requirements-txt-fixer = pre_commit_hooks.requirements_txt_fixer:main
     sort-simple-yaml = pre_commit_hooks.sort_simple_yaml:main
     trailing-whitespace-fixer = pre_commit_hooks.trailing_whitespace_fixer:main
+    enforce-branch-name = pre_commit_hooks.enforce_branch_name:main
 
 [bdist_wheel]
 universal = True