[yaml]: fix provider testing issue

sdks/python/apache_beam/yaml/yaml_provider.py

@@ -490,7 +490,7 @@ def json_config_schema(self, type):
     return dict(
         type='object',
         additionalProperties=False,
-        **self._transforms[type]['config_schema'])
+        **self._transforms[type].get('config_schema', {}))
 
   def description(self, type):
     return self._transforms[type].get('description')

sdks/python/apache_beam/yaml/yaml_testing.py

@@ -73,12 +73,15 @@ def __str__(self):
 
 def run_test(pipeline_spec, test_spec, options=None, fix_failures=False):
   if isinstance(pipeline_spec, str):
-    pipeline_spec = yaml.load(pipeline_spec, Loader=yaml_utils.SafeLineLoader)
+    pipeline_spec_dict = yaml.load(
+        pipeline_spec, Loader=yaml_utils.SafeLineLoader)
+  else:
+    pipeline_spec_dict = pipeline_spec
 
-  pipeline_spec = _preprocess_for_testing(pipeline_spec)
+  processed_pipeline_spec = _preprocess_for_testing(pipeline_spec_dict)
 
   transform_spec, recording_ids = inject_test_tranforms(
-      pipeline_spec,
+      processed_pipeline_spec,
       test_spec,
       fix_failures)
 
@@ -96,12 +99,18 @@ def run_test(pipeline_spec, test_spec, options=None, fix_failures=False):
     options = beam.options.pipeline_options.PipelineOptions(
         pickle_library='cloudpickle',
         **yaml_transform.SafeLineLoader.strip_metadata(
-            pipeline_spec.get('options', {})))
+            pipeline_spec_dict.get('options', {})))
+
+  providers = yaml_provider.merge_providers(
+      yaml_provider.parse_providers(
+          '', pipeline_spec_dict.get('providers', [])),
+      {
+          'AssertEqualAndRecord': yaml_provider.as_provider_list(
+              'AssertEqualAndRecord', AssertEqualAndRecord)
+      })
 
   with beam.Pipeline(options=options) as p:
-    _ = p | yaml_transform.YamlTransform(
-        transform_spec,
-        providers={'AssertEqualAndRecord': AssertEqualAndRecord})
+    _ = p | yaml_transform.YamlTransform(transform_spec, providers=providers)
 
   if fix_failures:
     fixes = {}

sdks/python/apache_beam/yaml/yaml_testing_test.py

@@ -322,6 +322,40 @@ def test_join_transform_serialization(self):
             }]
         })
 
+  def test_toplevel_providers(self):
+    yaml_testing.run_test(
+        '''
+        pipeline:
+          type: chain
+          transforms:
+            - type: Create
+              config:
+                elements: [1, 2, 3]
+            - type: MyDoubler
+        providers:
+          - type: yaml
+            transforms:
+              MyDoubler:
+                body:
+                  type: MapToFields
+                  config:
+                    language: python
+                    fields:
+                      doubled: element * 2
+        ''',
+        {
+            'expected_outputs': [{
+                'name': 'MyDoubler',
+                'elements': [{
+                    'doubled': 2
+                }, {
+                    'doubled': 4
+                }, {
+                    'doubled': 6
+                }]
+            }]
+        })
+
 
 if __name__ == '__main__':
   logging.getLogger().setLevel(logging.INFO)