Detecting and handling PDM's symlinked packages

CHANGES.rst

@@ -1,3 +1,10 @@
+v6.7.0
+======
+
+* #453: When inferring top-level names that are importable for
+  distributions in ``package_distributions``, now symlinks to
+  other directories are honored.
+
 v6.6.0
 ======
 

importlib_metadata/__init__.py

@@ -981,30 +981,34 @@ def _topmost(name: PackagePath) -> Optional[str]:
     return top if rest else None
 
 
-def _get_toplevel_name(name: PackagePath) -> Optional[str]:
+def _get_toplevel_name(name: PackagePath) -> str:
     """
     Infer a possibly importable module name from a name presumed on
     sys.path.
 
     >>> _get_toplevel_name(PackagePath('foo.py'))
     'foo'
+    >>> _get_toplevel_name(PackagePath('foo'))
+    'foo'
     >>> _get_toplevel_name(PackagePath('foo.pyc'))
     'foo'
     >>> _get_toplevel_name(PackagePath('foo/__init__.py'))
     'foo'
     >>> _get_toplevel_name(PackagePath('foo.pth'))
+    'foo.pth'
     >>> _get_toplevel_name(PackagePath('foo.dist-info'))
+    'foo.dist-info'
     """
     return _topmost(name) or (
         # python/typeshed#10328
         inspect.getmodulename(name)  # type: ignore
+        or str(name)
     )
 
 
 def _top_level_inferred(dist):
     opt_names = set(map(_get_toplevel_name, always_iterable(dist.files)))
 
-    @pass_none
     def importable_name(name):
         return '.' not in name
 

tests/test_main.py

@@ -9,6 +9,7 @@
 
 from . import fixtures
 from ._context import suppress
+from ._path import Symlink
 from importlib_metadata import (
     Distribution,
     EntryPoint,
@@ -399,6 +400,27 @@ def test_packages_distributions_all_module_types(self):
 
         assert not any(name.endswith('.dist-info') for name in distributions)
 
+    def test_packages_distributions_symlinked_top_level(self):
+        """
+        Distribution is resolvable from a simple top-level symlink in RECORD.
+        See #452.
+        """
+
+        files: fixtures.FilesSpec = {
+            "symlinked_pkg-1.0.0.dist-info": {
+                "METADATA": """
+                    Name: symlinked-pkg
+                    Version: 1.0.0
+                    """,
+                "RECORD": "symlinked,,\n",
+            },
+            ".symlink.target": {},
+            "symlinked": Symlink(".symlink.target"),
+        }
+
+        fixtures.build_files(files, self.site_dir)
+        assert packages_distributions()['symlinked'] == ['symlinked-pkg']
+
 
 class PackagesDistributionsEggTest(
     fixtures.EggInfoPkg,