pre-commit: Always run qmlformat and require to skip the hook if needed

.pre-commit-config.yaml

@@ -126,16 +126,11 @@ repos:
     - manual
   - id: qmlformat
     name: qmlformat
-    entry: qmlformat -i
+    entry: tools/qmlformat.py
     pass_filenames: true
-    require_serial: true
     language: system
     types: [text]
     files: ^.*\.qml$
-    # Not enabled in commit stage by default, because qmlformat requires Qt
-    # 5.15 to be installed
-    stages:
-    - manual
   - id: qmllint
     name: qmllint
     entry: qmllint

tools/qmlformat.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+"""
+Small qmlformat wrapper that warns the user if the tool is not installed.
+"""
+import argparse
+import shutil
+import subprocess
+import pathlib
+import sys
+
+QMLFORMAT_MISSING_MESSAGE = """
+qmlformat is not installed. It is included in Qt 5.15 and later. If that Qt
+version is not available on your system, please use the SKIP environment
+variable when committing:
+
+    $ SKIP=qmlformat git commit
+"""
+
+
+def main(argv=None):
+    qmlformat_executable = shutil.which("qmlformat")
+    if not qmlformat_executable:
+        print(QMLFORMAT_MISSING_MESSAGE.strip(), file=sys.stderr)
+        return 1
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("file", nargs="+", type=pathlib.Path)
+    args = parser.parse_args(argv)
+
+    for filename in args.file:
+        subprocess.call((qmlformat_executable, "-i", filename))
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())