filter out non-documented branches

Author: escherize

.github/workflows/process_docs_changes.yml

@@ -34,6 +34,10 @@ jobs:
         with:
           babashka-version: 1.12.199
 
+      - name: Filter non-documented branches
+        run: |
+          bb script/check_incoming_branchname.clj $MAIN_REPO_BRANCH
+
       - name: Install js dependencies
         run: yarn install --frozen-lockfile --prefer-offline
 

script/check_incoming_branchname.clj

@@ -0,0 +1,34 @@
+(ns check-incoming-branchname)
+
+(defn usage []
+  (println "Usage: script/check_incoming_branchname.clj branchname")
+  (System/exit 1))
+
+(def release-regex #"release-x\.(\d+)\.x")
+
+(defn extract-release-num [release-branchname]
+  (let [[_ num] (re-matches release-regex release-branchname)]
+    num))
+
+(defn categorize-branchname [branchname]
+  (cond
+    (= branchname "master") [:master]
+    (re-matches release-regex branchname) [:release (extract-release-num branchname)]))
+
+(defn -main
+  "This is called from the `process_docs_changes.yml` workflow. It checks that
+   the branchname is either `master` or a release branch. If not, it exits with
+   an error code, stopping the workflow before it goes ahead and opens a PR with
+   the docs changes."
+  [& args]
+  (let [branchname (or (first args) (usage))
+        _ (println "Checking branchname:" branchname)
+        [category release-num] (categorize-branchname branchname)]
+    (case category
+      :master (println "Master branch detected.")
+      :release (println "Release branch detected:" release-num)
+      (do (println "Unpublishable branchname: " branchname)
+          (System/exit 1)))))
+
+(when (= *file* (System/getProperty "babashka.file"))
+  (apply -main *command-line-args*))