pr: addresses pr feedback.

Author: atulep

google/api_core/exceptions.py

@@ -105,7 +105,7 @@ class GoogleAPICallError(GoogleAPIError, metaclass=_GoogleAPICallErrorMeta):
         response (Union[requests.Request, grpc.Call]): The response or
             gRPC call metadata.
         error_info (Union[error_details_pb2.ErrorInfo, None]): An optional object containing error info
-            (google.rpc.error_details.ErrorInfo)
+            (google.rpc.error_details.ErrorInfo).
     """
 
     code: Union[int, None] = None
@@ -149,15 +149,46 @@ def errors(self):
         return list(self._errors)
 
     @property
-    def error_info(self):
-        """Information contained in google.rpc.error_details.ErrorInfo
+    def reason(self):
+        """The reason of the error.
 
         Reference:
             https://github.com/googleapis/googleapis/blob/master/google/rpc/error_details.proto#L112
+
+        Returns:
+            Union[str, None]: An optional string containing reason of the error.
+        """
+        if not self._error_info:
+            return None
+        return self._error_info.reason
+
+    @property
+    def domain(self):
+        """The logical grouping to which the "reason" belongs.
+
+        Reference:
+            https://github.com/googleapis/googleapis/blob/master/google/rpc/error_details.proto#L112
+
+        Returns:
+            Union[str, None]: An optional string containing a logical grouping to which the "reason" belongs.
+        """
+        if not self._error_info:
+            return None
+        return self._error_info.domain
+
+    @property
+    def metadata(self):
+        """Additional structured details about this error
+
+        Reference:
+            https://github.com/googleapis/googleapis/blob/master/google/rpc/error_details.proto#L112
+
         Returns:
-            Union[error_details_pb2.ErrorInfo, None]: An optional object containing google.rpc.error_details.ErrorInfo.
+            Union[Dict[str, str], None]: An optional object containing structured details about the error.
         """
-        return self._error_info
+        if not self._error_info:
+            return None
+        return self._error_info.metadata
 
     @property
     def details(self):

tests/unit/test_exceptions.py

@@ -302,9 +302,9 @@ def test_error_details_from_rest_response():
 
     # See JSON schema in https://cloud.google.com/apis/design/errors#http_mapping
     http_response = make_response(
-        json.dumps({"error": json.loads(json_format.MessageToJson(status, sort_keys=True))}).encode(
-            "utf-8"
-        )
+        json.dumps(
+            {"error": json.loads(json_format.MessageToJson(status, sort_keys=True))}
+        ).encode("utf-8")
     )
     exception = exceptions.from_http_response(http_response)
     want_error_details = [
@@ -336,7 +336,11 @@ def test_error_details_from_v1_rest_response():
     )
     exception = exceptions.from_http_response(response)
     assert exception.details == []
-    assert exception.error_info is None
+    assert (
+        exception.reason is None
+        and exception.domain is None
+        and exception.metadata is None
+    )
 
 
 @pytest.mark.skipif(grpc is None, reason="gRPC not importable")
@@ -362,7 +366,9 @@ def test_error_details_from_grpc_response():
     status_br_detail.Unpack(bad_request_detail)
     status_ei_detail.Unpack(error_info_detail)
     assert exception.details == [bad_request_detail, error_info_detail]
-    assert exception.error_info == error_info_detail
+    assert exception.reason == error_info_detail.reason
+    assert exception.domain == error_info_detail.domain
+    assert exception.metadata == error_info_detail.metadata
 
 
 @pytest.mark.skipif(grpc is None, reason="gRPC not importable")
@@ -381,4 +387,8 @@ def test_error_details_from_grpc_response_unknown_error():
         m.return_value = status
         exception = exceptions.from_grpc_error(error)
     assert exception.details == [status_detail]
-    assert exception.error_info is None
+    assert (
+        exception.reason is None
+        and exception.domain is None
+        and exception.metadata is None
+    )