gh-145260: Fix importlib.resources.simple ResourceContainer and ResourceHandle

ResourceContainer and ResourceHandle could not be instantiated because
Traversable now requires name as an abstract property. Additionally,
ResourceContainer.iterdir() accessed self.reader.resources without
calling it, and ResourceHandle.joinpath had a signature mismatch.

- Add name property to ResourceContainer
- Fix self.reader.resources -> self.reader.resources() call
- Add iterdir() method to ResourceHandle
- Fix ResourceHandle.joinpath to accept *descendants

Author: stefanzetzsche

Lib/importlib/resources/simple.py

@@ -55,14 +55,18 @@ class ResourceContainer(Traversable):
     def __init__(self, reader: SimpleReader):
         self.reader = reader
 
+    @property
+    def name(self):
+        return self.reader.name
+
     def is_dir(self):
         return True
 
     def is_file(self):
         return False
 
     def iterdir(self):
-        files = (ResourceHandle(self, name) for name in self.reader.resources)
+        files = (ResourceHandle(self, name) for name in self.reader.resources())
         dirs = map(ResourceContainer, self.reader.children())
         return itertools.chain(files, dirs)
 
@@ -85,13 +89,18 @@ def is_file(self):
     def is_dir(self):
         return False
 
+    def iterdir(self):
+        return iter([])
+
     def open(self, mode='r', *args, **kwargs):
         stream = self.parent.reader.open_binary(self.name)
         if 'b' not in mode:
             stream = io.TextIOWrapper(stream, *args, **kwargs)
         return stream
 
-    def joinpath(self, name):
+    def joinpath(self, *descendants):
+        if not descendants:
+            return self
         raise RuntimeError("Cannot traverse into a resource")