properly handle region_name in MPath for S3 paths

mapchete/path.py

@@ -158,6 +158,13 @@ def fs(self) -> fsspec.AbstractFileSystem:
         if self._fs is not None:
             return self._fs
         elif self._path_str.startswith("s3://"):
+            # move 'region_name' up to client_kwargs in order to have effect
+            if self._storage_options.get("region_name"):
+                client_kwargs = self._storage_options.get("client_kwargs", {})
+                client_kwargs.update(
+                    region_name=self._storage_options.pop("region_name")
+                )
+                self._storage_options.update(client_kwargs=client_kwargs)
             return fsspec.filesystem(
                 "s3",
                 requester_pays=self._storage_options.get(

test/test_path.py

@@ -527,3 +527,11 @@ def test_with_protocol_http():
 def test_with_protocol_relative():
     path = MPath("foo/bar")
     assert path.with_protocol("https") == "https://foo/bar"
+
+
+def test_s3_region_name():
+    path = MPath("s3://foo", storage_options=dict(region_name="bar"))
+    # trigger a rewrite of storage options to fit with S3FS
+    path.fs
+    # not an ideal way to test this, but the storage_options are passed on to S3FS that way
+    assert path._storage_options.get("client_kwargs", {}).get("region_name") == "bar"