DEV: Ensure that the PR titles have the correct format (#2378)

.github/scripts/check_pr_title.py

@@ -0,0 +1,32 @@
+"""Check that all PR titles follow the desired scheme."""  # noqa: INP001
+
+import os
+import sys
+
+KNOWN_PREFIXES = (
+    "SEC: ",
+    "BUG: ",
+    "ENH: ",
+    "DEP: ",
+    "PI: ",
+    "ROB: ",
+    "DOC: ",
+    "TST: ",
+    "DEV: ",
+    "STY: ",
+    "MAINT: ",
+)
+PR_TITLE = os.getenv("PR_TITLE", "")
+
+if not PR_TITLE.startswith(KNOWN_PREFIXES) or not PR_TITLE.split(": ", maxsplit=1)[1]:
+    sys.stderr.write(
+        f"The PR title '{PR_TITLE}' does not follow the projects naming scheme: "
+        "https://pypdf.readthedocs.io/en/latest/dev/intro.html#commit-messages\n",
+    )
+    sys.stderr.write(
+        "If you do not know which one to choose or if multiple apply, make a best guess. "
+        "Nobody will complain if it does not quite fit :-)\n",
+    )
+    sys.exit(1)
+else:
+    sys.stdout.write(f"PR title '{PR_TITLE}' appears to be valid.\n")

.github/workflows/github-ci.yaml

@@ -164,6 +164,12 @@ jobs:
     - name: Test with mypy
       run : |
         mypy pypdf
+    - name: Check PR title
+      env:
+          PR_TITLE: ${{ github.event.pull_request.title }}
+      run: |
+          python .github/scripts/check_pr_title.py
+      if: github.event_name == 'pull_request'
 
   package:
     name: Build & verify package