fix: snippetgen handling of repeated enum field (#1443)

* fix: snippetgen handling of repeated enum field

Author: dizcology

packages/gapic-generator/gapic/samplegen/samplegen.py

@@ -364,7 +364,8 @@ def _normal_request_setup(self, base_param_to_attrs, val, request, field):
             elif attr.enum:
                 # A little bit hacky, but 'values' is a list, and this is the easiest
                 # way to verify that the value is a valid enum variant.
-                witness = any(e.name == val for e in attr.enum.values)
+                # Here val could be a list of a single enum value name.
+                witness = any(e.name in val for e in attr.enum.values)
                 if not witness:
                     raise types.InvalidEnumVariant(
                         "Invalid variant for enum {}: '{}'".format(attr, val)
@@ -974,8 +975,14 @@ def generate_request_object(api_schema: api.API, service: wrappers.Service, mess
                 {"field": field_name, "value": field.mock_value_original_type})
         elif field.enum:
             # Choose the last enum value in the list since index 0 is often "unspecified"
+            enum_value = field.enum.values[-1].name
+            if field.repeated:
+                field_value = [enum_value]
+            else:
+                field_value = enum_value
+
             request.append(
-                {"field": field_name, "value": field.enum.values[-1].name})
+                {"field": field_name, "value": field_value})
         else:
             # This is a message type, recurse
             # TODO(busunkim):  Some real world APIs have
@@ -1023,7 +1030,7 @@ def generate_sample_specs(api_schema: api.API, *, opts) -> Generator[Dict[str, A
                 spec = {
                     "rpc": rpc_name,
                     "transport": transport,
-                    # `request` and `response` is populated in `preprocess_sample`
+                    # `request` and `response` are populated in `preprocess_sample`
                     "service": f"{api_schema.naming.proto_package}.{service_name}",
                     "region_tag": region_tag,
                     "description": f"Snippet for {utils.to_snake_case(rpc_name)}"

packages/gapic-generator/tests/unit/samplegen/test_samplegen.py

@@ -203,7 +203,9 @@ def test_preprocess_sample():
     ]
 
 
-def test_preprocess_sample_with_enum_field():
+@pytest.mark.parametrize(
+    'repeated_enum,expected', [(False, "TYPE_2"), (True, ["TYPE_2"])])
+def test_preprocess_sample_with_enum_field(repeated_enum, expected):
     # Verify that the default response is added.
     sample = {"service": "Mollusc", "rpc": "Classify"}
 
@@ -212,6 +214,7 @@ def test_preprocess_sample_with_enum_field():
             "type": DummyField(
                 name="type",
                 required=True,
+                repeated=repeated_enum,
                 type=enum_factory("type", ["TYPE_1", "TYPE_2"]),
                 enum=enum_factory("type", ["TYPE_1", "TYPE_2"])
                 )
@@ -255,7 +258,7 @@ def test_preprocess_sample_with_enum_field():
     assert sample["request"] == [
         {
             "field": "type",
-            "value": "TYPE_2"
+            "value": expected
         }
     ]