Fix bundle-extensions script to work on recent importlib-resources. (#5050)

Also adds a test case for running the script.

bin/bundle-extensions

@@ -6,8 +6,8 @@ from pathlib import Path
 from shutil import copy
 from collections import OrderedDict as odict
 
-from importlib_metadata import entry_points
-from importlib_resources import contents, is_resource, path
+import importlib_metadata
+import importlib_resources
 
 # Name of the subdirectory
 BUNDLE_DIRECTORY = "bundle"
@@ -25,18 +25,6 @@ if not extensions_directory.exists():
 os.environ["EXTENSIONS_DIRECTORY"] = str(extensions_relative_path)
 
 
-def resource_isdir(module, resource):
-    """Whether a given resource is a directory in the given module
-
-    https://importlib-resources.readthedocs.io/en/latest/migration.html#pkg-resources-resource-isdir
-    """
-    try:
-        return resource in contents(module) and not is_resource(module, resource)
-    except (ImportError, TypeError):
-        # module isn't a package, so can't have a subdirectory/-package
-        return False
-
-
 def entry_point_module(entry_point):
     """Returns the dotted module path for the given entry point"""
     return entry_point.pattern.match(entry_point.value).group("module")
@@ -77,18 +65,28 @@ def load_bundles():
 
     """
     bundles = odict()
-    for entry_point in entry_points().get("redash.bundles", []):
+    for entry_point in importlib_metadata.entry_points().get("redash.bundles", []):
         logger.info('Loading Redash bundle "%s".', entry_point.name)
         module = entry_point_module(entry_point)
         # Try to get a list of bundle files
-        if not resource_isdir(module, BUNDLE_DIRECTORY):
+        try:
+            bundle_dir = importlib_resources.files(module).joinpath(BUNDLE_DIRECTORY)
+        except (ImportError, TypeError):
+            # Module isn't a package, so can't have a subdirectory/-package
             logger.error(
-                'Redash bundle directory "%s" could not be found.', entry_point.name
+                'Redash bundle module "%s" could not be imported: "%s"',
+                entry_point.name,
+                module,
             )
             continue
-        with path(module, BUNDLE_DIRECTORY) as bundle_dir:
-            bundles[entry_point.name] = list(bundle_dir.rglob("*"))
-
+        if not bundle_dir.is_dir():
+            logger.error(
+                'Redash bundle directory "%s" could not be found or is not a directory: "%s"',
+                entry_point.name,
+                bundle_dir,
+            )
+            continue
+        bundles[entry_point.name] = list(bundle_dir.rglob("*"))
     return bundles