ensure file existence checks are case-sensitive

wikitools/file_utils.py

@@ -1,6 +1,7 @@
 import fnmatch
 import os
 import typing
+import pathlib
 
 
 class ChangeDirectory:
@@ -21,6 +22,24 @@ def normalised(path: str) -> str:
     return normalised
 
 
+def exists(path: pathlib.Path):
+    """
+    Case-sensitive file existence check
+
+    File paths are case-insensitive on some operating systems like Windows, but we rely on file existence checks to take casing into account
+    """
+
+    if os.name == 'nt':
+        try:
+            path_string = path.as_posix()
+            # windows disallows two files that differ only in casing, so there are no special considerations for that
+            return normalised(path_string) == normalised(os.path.relpath(os.path.realpath(path_string, strict=True)))
+        except OSError:
+            return False
+    else:
+        return path.exists()
+
+
 def is_newspost(path: str) -> bool:
     return (
         normalised(os.path.dirname(path)).startswith("news") and

wikitools/link_checker.py

@@ -3,7 +3,7 @@
 import typing
 
 from wikitools import redirect_parser, reference_parser, errors, link_parser, article_parser
-from wikitools import console
+from wikitools import console, file_utils
 
 
 def check_link(
@@ -35,7 +35,7 @@ def check_link(
         repo_target = pathlib.Path(f"news/{year}/{target.name}")
         location = '/' + repo_target.as_posix()
 
-        if not repo_target.exists():
+        if not file_utils.exists(repo_target):
             # news posts don't have redirects
             return errors.LinkNotFoundError(link, reference, location)
         else:
@@ -67,15 +67,15 @@ def check_link(
 
     target = pathlib.Path(location[1:])  # strip leading slash
     # no article? could be a redirect
-    if not target.exists():
+    if not file_utils.exists(target):
         redirect_source = target.relative_to('wiki').as_posix()
         try:
             redirect_destination, redirect_line_no = redirects[redirect_source.lower()]
         except KeyError:
             return errors.LinkNotFoundError(link, reference, location)
 
         target = pathlib.Path('wiki') / redirect_destination
-        if not target.exists():
+        if not file_utils.exists(target):
             return errors.BrokenRedirectError(link, redirect_source, redirect_line_no, redirect_destination)
 
     # link to an article in general, article exists -> good