feat(gapic-common): Compatibility with protobuf v23 generated map fie…

…lds (#948)

gapic-common/lib/gapic/protobuf.rb

@@ -16,7 +16,8 @@
 
 module Gapic
  ##
- # TODO: Describe Protobuf
+ # A set of internal utilities for coercing data to protobuf messages.
+ #
  module Protobuf
  ##
  # Creates an instance of a protobuf message from a hash that may include nested hashes. `google/protobuf` allows
@@ -31,10 +32,13 @@ module Protobuf
  def self.coerce hash, to:
  return hash if hash.is_a? to
 
+ # Special case handling of certain types
+ return time_to_timestamp hash if to == Google::Protobuf::Timestamp && hash.is_a?(Time)
+
  # Sanity check: input must be a Hash
  raise ArgumentError, "Value #{hash} must be a Hash or a #{to.name}" unless hash.is_a? Hash
 
- hash = coerce_submessages hash, to
+ hash = coerce_submessages hash, to.descriptor
  to.new hash
  end
 
@@ -44,89 +48,58 @@ def self.coerce hash, to:
  # @private
  #
  # @param hash [Hash] The hash whose nested hashes will be coerced.
- # @param message_class [Class] The corresponding protobuf message class of the given hash.
+ # @param message_descriptor [Google::Protobuf::Descriptor] The protobuf descriptor for the message.
  #
  # @return [Hash] A hash whose nested hashes have been coerced.
- def self.coerce_submessages hash, message_class
+ def self.coerce_submessages hash, message_descriptor
  return nil if hash.nil?
  coerced = {}
- message_descriptor = message_class.descriptor
  hash.each do |key, val|
  field_descriptor = message_descriptor.lookup key.to_s
- coerced[key] = if field_descriptor && field_descriptor.type == :message
- coerce_submessage val, field_descriptor
- elsif field_descriptor && field_descriptor.type == :bytes &&
- (val.is_a?(IO) || val.is_a?(StringIO))
- val.binmode.read
- else
- # `google/protobuf` should throw an error if no field descriptor is
- # found. Simply pass through.
- val
- end
+ coerced[key] =
+ if field_descriptor&.type == :message
+ coerce_submessage val, field_descriptor
+ elsif field_descriptor&.type == :bytes && (val.is_a?(IO) || val.is_a?(StringIO))
+ val.binmode.read
+ else
+ # For non-message fields, just pass the scalar value through.
+ # Note: if field_descriptor is not found, we just pass the value
+ # through and let protobuf raise an error.
+ val
+ end
  end
  coerced
  end
 
  ##
- # Coerces the value of a field to be acceptable by the instantiation method of the wrapping message.
+ # Coerces a message-typed field.
+ # The field can be a normal single message, a repeated message, or a map.
  #
  # @private
  #
- # @param val [Object] The value to be coerced.
- # @param field_descriptor [Google::Protobuf::FieldDescriptor] The field descriptor of the value.
+ # @param val [Object] The value to coerce
+ # @param field_descriptor [Google::Protobuf::FieldDescriptor] The field descriptor.
  #
- # @return [Object] The coerced version of the given value.
  def self.coerce_submessage val, field_descriptor
- if (field_descriptor.label == :repeated) && !(map_field? field_descriptor)
- coerce_array val, field_descriptor
- elsif field_descriptor.subtype.msgclass == Google::Protobuf::Timestamp && val.is_a?(Time)
- time_to_timestamp val
+ if val.is_a? Array
+ # Assume this is a repeated message field, iterate over it and coerce
+ # each to the message class.
+ # Protobuf will raise an error if this assumption is incorrect.
+ val.map do |elem|
+ coerce elem, to: field_descriptor.subtype.msgclass
+ end
+ elsif field_descriptor.label == :repeated
+ # Non-array passed to a repeated field: assume this is a map, and that
+ # a hash is being passed, and let protobuf handle the conversion.
+ # Protobuf will raise an error if this assumption is incorrect.
+ val
  else
- coerce_value val, field_descriptor
- end
- end
-
- ##
- # Coerces the values of an array to be acceptable by the instantiation method the wrapping message.
- #
- # @private
- #
- # @param array [Array<Object>] The values to be coerced.
- # @param field_descriptor [Google::Protobuf::FieldDescriptor] The field descriptor of the values.
- #
- # @return [Array<Object>] The coerced version of the given values.
- def self.coerce_array array, field_descriptor
- raise ArgumentError, "Value #{array} must be an array" unless array.is_a? Array
- array.map do |val|
- coerce_value val, field_descriptor
+ # Assume this is a normal single message, and coerce to the message
+ # class.
+ coerce val, to: field_descriptor.subtype.msgclass
  end
  end
 
- ##
- # Hack to determine if field_descriptor is for a map.
- #
- # TODO(geigerj): Remove this once protobuf Ruby supports an official way
- # to determine if a FieldDescriptor represents a map.
- # See: https://github.com/google/protobuf/issues/3425
- def self.map_field? field_descriptor
- (field_descriptor.label == :repeated) &&
- (field_descriptor.subtype.name.include? "_MapEntry_")
- end
-
- ##
- # Coerces the value of a field to be acceptable by the instantiation method of the wrapping message.
- #
- # @private
- #
- # @param val [Object] The value to be coerced.
- # @param field_descriptor [Google::Protobuf::FieldDescriptor] The field descriptor of the value.
- #
- # @return [Object] The coerced version of the given value.
- def self.coerce_value val, field_descriptor
- return val unless (val.is_a? Hash) && !(map_field? field_descriptor)
- coerce val, to: field_descriptor.subtype.msgclass
- end
-
  ##
  # Utility for converting a Google::Protobuf::Timestamp instance to a Ruby time.
  #
@@ -147,6 +120,6 @@ def self.time_to_timestamp time
  Google::Protobuf::Timestamp.new seconds: time.to_i, nanos: time.nsec
  end
 
- private_class_method :coerce_submessages, :coerce_submessage, :coerce_array, :coerce_value, :map_field?
+ private_class_method :coerce_submessages, :coerce_submessage
  end
 end

gapic-common/test/fixtures/fixture2.proto

@@ -0,0 +1,22 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package gapic.examples;
+
+message MapTest {
+ string name = 1;
+ map<string, string> map_field = 4;
+}

gapic-common/test/gapic/protobuf/coerce_test.rb

@@ -75,7 +75,7 @@ class ProtobufCoerceTest < Minitest::Spec
  end
  end
 
- it "handles maps" do
+ it "handles maps using the DSL" do
  request_hash = { name: USER_NAME, map_field: MAP }
  user = Gapic::Protobuf.coerce request_hash, to: Gapic::Examples::User
  _(user).must_be_kind_of Gapic::Examples::User
@@ -86,6 +86,17 @@ class ProtobufCoerceTest < Minitest::Spec
  end
  end
 
+ it "handles maps using raw descriptor strings" do
+ request_hash = { name: USER_NAME, map_field: MAP }
+ obj = Gapic::Protobuf.coerce request_hash, to: Gapic::Examples::MapTest
+ _(obj).must_be_kind_of Gapic::Examples::MapTest
+ _(obj.name).must_equal USER_NAME
+ _(obj.map_field).must_be_kind_of Google::Protobuf::Map
+ obj.map_field.each do |k, v|
+ _(MAP[k]).must_equal v
+ end
+ end
+
  it "handles IO instances" do
  file = File.new "test/fixtures/fixture_file.txt"
  request_hash = { bytes_field: file }

gapic-common/test/test_helper.rb

@@ -22,6 +22,7 @@
 require "gapic/rest"
 require "google/protobuf/any_pb"
 require_relative "./fixtures/fixture_pb"
+require_relative "./fixtures/fixture2_pb"
 require_relative "./fixtures/transcoding_example_pb"
 
 class FakeFaradayError < ::Faraday::Error