Search returns same class as self - allowing subclassing (#417)

Author: aulemahal

intake_esm/core.py

@@ -344,7 +344,7 @@ def search(
                 .reset_index(drop=True)
             )
 
-        cat = esm_datastore({'esmcat': self.esmcat.dict(), 'df': esmcat_results})
+        cat = self.__class__({'esmcat': self.esmcat.dict(), 'df': esmcat_results})
         if self.esmcat.has_multiple_variable_assets:
             requested_variables = query.get(
                 self.esmcat.aggregation_control.variable_column_name, []

tests/test_core.py

@@ -411,3 +411,12 @@ def funcs(ds):
         new_cat.to_dataset_dict(
             xarray_open_kwargs={'backend_kwargs': {'storage_options': {'anon': True}}}
         )
+
+
+def test_subclassing_catalog():
+    class ChildCatalog(intake_esm.esm_datastore):
+        pass
+
+    cat = ChildCatalog(catalog_dict_records)
+    scat = cat.search(variable=['FOO', 'BAR'])
+    assert type(scat) is ChildCatalog