1 files changed, 98 insertions, 10 deletions
diff --git a/Lib/importlib/_adapters.py b/Lib/importlib/_adapters.py
index eedde49..9907b14 100644
--- a/Lib/importlib/_adapters.py
+++ b/Lib/importlib/_adapters.py
@@ -1,4 +1,5 @@
 from contextlib import suppress
+from io import TextIOWrapper
 
 from . import abc
 
@@ -25,32 +26,119 @@ class TraversableResourcesLoader:
         self.spec = spec
 
     def get_resource_reader(self, name):
-        return DegenerateFiles(self.spec)._native()
+        return CompatibilityFiles(self.spec)._native()
 
 
-class DegenerateFiles:
+def _io_wrapper(file, mode='r', *args, **kwargs):
+    if mode == 'r':
+        return TextIOWrapper(file, *args, **kwargs)
+    elif mode == 'rb':
+        return file
+    raise ValueError(
+        "Invalid mode value '{}', only 'r' and 'rb' are supported".format(mode)
+    )
+
+
+class CompatibilityFiles:
     """
     Adapter for an existing or non-existant resource reader
-    to provide a degenerate .files().
+    to provide a compability .files().
     """
 
-    class Path(abc.Traversable):
+    class SpecPath(abc.Traversable):
+        """
+        Path tied to a module spec.
+        Can be read and exposes the resource reader children.
+        """
+
+        def __init__(self, spec, reader):
+            self._spec = spec
+            self._reader = reader
+
+        def iterdir(self):
+            if not self._reader:
+                return iter(())
+            return iter(
+                CompatibilityFiles.ChildPath(self._reader, path)
+                for path in self._reader.contents()
+            )
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            if not self._reader:
+                return CompatibilityFiles.OrphanPath(other)
+            return CompatibilityFiles.ChildPath(self._reader, other)
+
+        @property
+        def name(self):
+            return self._spec.name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(self._reader.open_resource(None), mode, *args, **kwargs)
+
+    class ChildPath(abc.Traversable):
+        """
+        Path tied to a resource reader child.
+        Can be read but doesn't expose any meaningfull children.
+        """
+
+        def __init__(self, reader, name):
+            self._reader = reader
+            self._name = name
+
         def iterdir(self):
             return iter(())
 
+        def is_file(self):
+            return self._reader.is_resource(self.name)
+
         def is_dir(self):
+            return not self.is_file()
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(self.name, other)
+
+        @property
+        def name(self):
+            return self._name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(
+                self._reader.open_resource(self.name), mode, *args, **kwargs
+            )
+
+    class OrphanPath(abc.Traversable):
+        """
+        Orphan path, not tied to a module spec or resource reader.
+        Can't be read and doesn't expose any meaningful children.
+        """
+
+        def __init__(self, *path_parts):
+            if len(path_parts) < 1:
+                raise ValueError('Need at least one path part to construct a path')
+            self._path = path_parts
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
             return False
 
-        is_file = exists = is_dir  # type: ignore
+        is_dir = is_file
 
         def joinpath(self, other):
-            return DegenerateFiles.Path()
+            return CompatibilityFiles.OrphanPath(*self._path, other)
 
+        @property
         def name(self):
-            return ''
+            return self._path[-1]
 
-        def open(self):
-            raise ValueError()
+        def open(self, mode='r', *args, **kwargs):
+            raise FileNotFoundError("Can't open orphan path")
 
     def __init__(self, spec):
         self.spec = spec
@@ -71,7 +159,7 @@ class DegenerateFiles:
         return getattr(self._reader, attr)
 
     def files(self):
-        return DegenerateFiles.Path()
+        return CompatibilityFiles.SpecPath(self.spec, self._reader)
 
 
 def wrap_spec(package):