Check formatting of project Turtle files

1 files changed, 58 insertions, 0 deletions

diff --git a/scripts/check_formatting.py b/scripts/check_formatting.py
new file mode 100755
index 00000000..e3342603
--- /dev/null
+++ b/scripts/check_formatting.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+
+# Copyright 2023 David Robillard <d@drobilla.net>
+# SPDX-License-Identifier: ISC
+
+"""Run a file through a formatter and error if the output differs."""
+
+import argparse
+import difflib
+import os
+import shlex
+import subprocess
+import sys
+
+DEVNULL = subprocess.DEVNULL
+PIPE = subprocess.PIPE
+
+
+def run_formatter(command, good_path):
+    """Run the formatter and compare the output."""
+
+    with subprocess.Popen(
+        command, stderr=DEVNULL, stdout=PIPE, encoding="utf-8"
+    ) as proc:
+        out = list(proc.stdout)
+
+    with open(good_path, "r", encoding="utf-8") as good:
+        good_lines = list(good)
+
+    same = True
+    for line in difflib.unified_diff(good_lines, out, fromfile=good_path):
+        sys.stderr.write(line)
+        same = False
+
+    return same
+
+
+def main():
+    """Run the command line tool."""
+
+    parser = argparse.ArgumentParser(
+        usage="%(prog)s [OPTION]... INPUT TOOL [ARG]...", description=__doc__
+    )
+
+    parser.add_argument("--wrapper", default="", help="executable wrapper")
+    parser.add_argument("input", help="file to check")
+    parser.add_argument("tool", help="formatter executable")
+    parser.add_argument("arg", nargs=argparse.REMAINDER, help="tool argument")
+
+    args = parser.parse_args(sys.argv[1:])
+    path = os.path.normpath(args.input)
+    command = shlex.split(args.wrapper) + [args.tool] + args.arg + [path]
+
+    return 0 if run_formatter(command, args.input) else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())