Adding upstream version 4.5.0+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pre_commit_hooks/check_yaml.py

@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+import argparse
+from typing import Any
+from typing import Generator
+from typing import NamedTuple
+from typing import Sequence
+
+import ruamel.yaml
+
+yaml = ruamel.yaml.YAML(typ='safe')
+
+
+def _exhaust(gen: Generator[str, None, None]) -> None:
+    for _ in gen:
+        pass
+
+
+def _parse_unsafe(*args: Any, **kwargs: Any) -> None:
+    _exhaust(yaml.parse(*args, **kwargs))
+
+
+def _load_all(*args: Any, **kwargs: Any) -> None:
+    _exhaust(yaml.load_all(*args, **kwargs))
+
+
+class Key(NamedTuple):
+    multi: bool
+    unsafe: bool
+
+
+LOAD_FNS = {
+    Key(multi=False, unsafe=False): yaml.load,
+    Key(multi=False, unsafe=True): _parse_unsafe,
+    Key(multi=True, unsafe=False): _load_all,
+    Key(multi=True, unsafe=True): _parse_unsafe,
+}
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-m', '--multi', '--allow-multiple-documents', action='store_true',
+    )
+    parser.add_argument(
+        '--unsafe', action='store_true',
+        help=(
+            'Instead of loading the files, simply parse them for syntax.  '
+            'A syntax-only check enables extensions and unsafe constructs '
+            'which would otherwise be forbidden.  Using this option removes '
+            'all guarantees of portability to other yaml implementations.  '
+            'Implies --allow-multiple-documents'
+        ),
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
+    args = parser.parse_args(argv)
+
+    load_fn = LOAD_FNS[Key(multi=args.multi, unsafe=args.unsafe)]
+
+    retval = 0
+    for filename in args.filenames:
+        try:
+            with open(filename, encoding='UTF-8') as f:
+                load_fn(f)
+        except ruamel.yaml.YAMLError as exc:
+            print(exc)
+            retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())