pathlib: Fix resolve() by overriding it in Python 3.5

1 files changed, 49 insertions, 0 deletions

diff --git a/mesonbuild/_pathlib.py b/mesonbuild/_pathlib.py
new file mode 100644
index 0000000..aac2a1b
--- /dev/null
+++ b/mesonbuild/_pathlib.py
@@ -0,0 +1,49 @@
+# Copyright 2020 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+import typing as T
+
+# Python 3.5 does not have the strict kwarg for resolve and always
+# behaves like calling resolve with strict=True in Python 3.6+
+#
+# This module emulates the behavior of Python 3.6+ by in Python 3.5 by
+# overriding the resolve method with a bit of custom logic
+#
+# TODO: Drop this module as soon as Python 3.5 support is dropped
+
+if T.TYPE_CHECKING:
+    from pathlib import Path
+else:
+    if sys.version_info.major <= 3 and sys.version_info.minor <= 5:
+
+        # Inspired by https://codereview.stackexchange.com/questions/162426/subclassing-pathlib-path
+        import pathlib
+        import os
+
+        # Can not directly inherit from pathlib.Path because the __new__
+        # operator of pathlib.Path() returns a {Posix,Windows}Path object.
+        class Path(type(pathlib.Path())):
+            def resolve(self, strict: bool = False) -> 'Path':
+                try:
+                    return super().resolve()
+                except FileNotFoundError:
+                    if strict:
+                        raise
+                    return Path(os.path.normpath(str(self)))
+
+    else:
+        from pathlib import Path
+
+from pathlib import PurePath, PureWindowsPath, PurePosixPath