feat(smithy): ec2Query protocol

Adds support for the `ec2Query` protocol which is used by the EC2 service exclusively.

Author: Dillon Nys

packages/smithy/smithy/lib/src/ast/traits.dart

@@ -19,6 +19,7 @@ export 'traits/aws/protocols/aws_json_1_0_trait.dart';
 export 'traits/aws/protocols/aws_json_1_1_trait.dart';
 export 'traits/aws/protocols/aws_protocol_trait.dart';
 export 'traits/aws/protocols/aws_query_trait.dart';
+export 'traits/aws/protocols/ec2_query_trait.dart';
 export 'traits/aws/protocols/rest_json_1_trait.dart';
 export 'traits/aws/protocols/rest_xml_trait.dart';
 export 'traits/aws/service_trait.dart';

packages/smithy/smithy/lib/src/ast/traits/aws/protocols/ec2_query_trait.dart

@@ -0,0 +1,48 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:json_annotation/json_annotation.dart';
+import 'package:smithy/ast.dart';
+
+part 'ec2_query_trait.g.dart';
+
+@JsonSerializable()
+class Ec2QueryTrait extends AWSProtocolTrait {
+  const Ec2QueryTrait()
+      : super(
+          id,
+          timestampFormat: TimestampFormat.dateTime,
+        );
+
+  factory Ec2QueryTrait.fromJson(Object? json) =>
+      _$Ec2QueryTraitFromJson((json as Map).cast<String, Object?>());
+
+  static const id = ShapeId(namespace: 'aws.protocols', shape: 'ec2Query');
+
+  @override
+  Map<String, Object?> toJson() => _$Ec2QueryTraitToJson(this);
+
+  @override
+  List<ShapeId> get traits => const [
+        CorsTrait.id,
+        EndpointTrait.id,
+        HostLabelTrait.id,
+        Ec2QueryNameTrait.id,
+        XmlAttributeTrait.id,
+        XmlFlattenedTrait.id,
+        XmlNameTrait.id,
+        XmlNamespaceTrait.id,
+        TimestampFormatTrait.id,
+      ];
+}
+
+/// Provides a custom name to use when serializing a structure member
+/// name as an EC2 query property.
+class Ec2QueryNameTrait extends StringTrait {
+  const Ec2QueryNameTrait(String value) : super(id, value);
+
+  factory Ec2QueryNameTrait.fromJson(Object? json) =>
+      Ec2QueryNameTrait(json as String);
+
+  static const id = ShapeId(namespace: 'aws.protocols', shape: 'ec2QueryName');
+}

packages/smithy/smithy/lib/src/ast/traits/aws/protocols/ec2_query_trait.g.dart

@@ -142,6 +142,8 @@ abstract class Trait<TraitValue extends Object>
     AwsQueryTrait.id: AwsQueryTrait.fromJson,
     AwsQueryErrorTrait.id: AwsQueryErrorTrait.fromJson,
     AwsQueryCompatibleTrait.id: AwsQueryCompatibleTrait.fromJson,
+    Ec2QueryTrait.id: Ec2QueryTrait.fromJson,
+    Ec2QueryNameTrait.id: Ec2QueryNameTrait.fromJson,
     RestJson1Trait.id: RestJson1Trait.fromJson,
     RestXmlTrait.id: RestXmlTrait.fromJson,
     S3UnwrappedXmlOutputTrait.id: S3UnwrappedXmlOutputTrait.fromJson,

packages/smithy/smithy/lib/src/ast/traits/trait.dart

@@ -9,9 +9,6 @@ import 'package:xml/xml.dart';
 class SmithyXmlPlugin implements SerializerPlugin {
   const SmithyXmlPlugin();
 
-  /// Extracts the root element from the response document.
-  XmlElement responseRootElement(XmlDocument document) => document.rootElement;
-
   @override
   Object? beforeSerialize(Object? object, FullType specifiedType) {
     if (specifiedType.isUnspecified) {
@@ -189,6 +186,9 @@ class SmithyXmlPlugin implements SerializerPlugin {
       if (object is! String || !object.startsWith('<')) {
         return object;
       }
+      if (specifiedType == const FullType(String)) {
+        return object;
+      }
       try {
         object = XmlDocument.parse(object);
       } on XmlParserException {
@@ -197,7 +197,7 @@ class SmithyXmlPlugin implements SerializerPlugin {
         return object;
       }
     }
-    return _deserialize(responseRootElement(object));
+    return _deserialize(object.rootElement);
   }
 
   @override

packages/smithy/smithy/lib/src/serialization/xml/smithy_xml_plugin.dart

@@ -4,6 +4,7 @@ abstract class XmlIndexer {
   static const XmlIndexer none = _NoneIndexer();
   static const XmlIndexer awsQueryList = _AwsQueryListIndexer();
   static const XmlIndexer awsQueryMap = _AwsQueryMapIndexer();
+  static const XmlIndexer ec2QueryList = _Ec2QueryListIndexer();
 
   String elementName(String name, int index);
 }
@@ -22,6 +23,13 @@ class _AwsQueryMapIndexer implements XmlIndexer {
   String elementName(String name, int index) => '${index + 1}.$name';
 }
 
+class _Ec2QueryListIndexer implements XmlIndexer {
+  const _Ec2QueryListIndexer();
+
+  @override
+  String elementName(String name, int index) => '${index + 1}';
+}
+
 class _NoneIndexer implements XmlIndexer {
   const _NoneIndexer();
 

packages/smithy/smithy/lib/src/serialization/xml/xml_indexer.dart

@@ -23,6 +23,7 @@ export 'src/http/retry/aws_retryer.dart' hide zMaxAttempts, zRetryAttempt;
 export 'src/protocol/aws_json_1_0.dart';
 export 'src/protocol/aws_json_1_1.dart';
 export 'src/protocol/aws_query_protocol.dart';
+export 'src/protocol/ec2_query.dart';
 export 'src/protocol/rest_json_1.dart';
 export 'src/protocol/rest_xml.dart';
 export 'src/s3/s3_client_config.dart';

packages/smithy/smithy_aws/lib/smithy_aws.dart

@@ -46,7 +46,7 @@ class AwsQueryProtocol<InputPayload, Input, OutputPayload, Output>
         );
 
   static final _coreSerializers = (Serializers().toBuilder()
-        ..addPlugin(const AwsQueryPlugin())
+        ..addPlugin(const SmithyXmlPlugin())
         ..addAll(const [
           QueryBoolSerializer(),
           QueryIntSerializer(),

packages/smithy/smithy_aws/lib/src/protocol/aws_query_protocol.dart

@@ -4,14 +4,6 @@ import 'package:built_value/serializer.dart';
 import 'package:smithy/smithy.dart';
 import 'package:xml/xml.dart';
 
-class AwsQueryPlugin extends SmithyXmlPlugin {
-  const AwsQueryPlugin();
-
-  @override
-  XmlElement responseRootElement(XmlDocument document) =>
-      document.rootElement.firstElementChild!;
-}
-
 class AwsQuerySerializer implements FullSerializer<List<int>> {
   AwsQuerySerializer(
     this._serializers, {

packages/smithy/smithy_aws/lib/src/protocol/aws_query_serializer.dart

@@ -0,0 +1,41 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'dart:convert';
+
+import 'package:aws_common/aws_common.dart';
+import 'package:smithy/ast.dart';
+import 'package:smithy_aws/src/protocol/aws_query_protocol.dart';
+import 'package:xml/xml.dart';
+
+class Ec2QueryProtocol<InputPayload, Input, OutputPayload, Output>
+    extends AwsQueryProtocol<InputPayload, Input, OutputPayload, Output> {
+  Ec2QueryProtocol({
+    required super.action,
+    required super.version,
+    super.requestInterceptors = const [],
+    super.responseInterceptors = const [],
+    super.serializers = const [],
+    super.builderFactories = const {},
+  });
+
+  @override
+  ShapeId get protocolId => Ec2QueryTrait.id;
+
+  @override
+  Future<String?> resolveErrorType(AWSBaseHttpResponse response) async {
+    try {
+      final body = await utf8.decodeStream(response.split());
+      final el = XmlDocument.parse(body).rootElement;
+      return el.childElements
+          .firstWhere((el) => el.name.local == 'Errors')
+          .childElements
+          .firstWhere((el) => el.name.local == 'Error')
+          .childElements
+          .firstWhere((el) => el.name.local == 'Code')
+          .innerText;
+    } on Exception {
+      return null;
+    }
+  }
+}