feat(aft): Generate AWS config (#3424)

* feat(aft): Generate AWS config

Generates the list of AWS services directly via the `aft generate sdk` command. Later, this will be expanded to include AWS regions and other common configuration values.

* chore(aft): Add generated code comment

packages/aft/lib/src/commands/generate/generate_sdk_command.dart

@@ -8,7 +8,9 @@ import 'dart:io';
 import 'package:aft/aft.dart';
 import 'package:aft/src/options/glob_options.dart';
 import 'package:async/async.dart';
+import 'package:aws_common/aws_common.dart';
 import 'package:checked_yaml/checked_yaml.dart';
+import 'package:code_builder/code_builder.dart';
 import 'package:collection/collection.dart';
 import 'package:git/git.dart';
 import 'package:path/path.dart' as p;
@@ -146,6 +148,9 @@ class GenerateSdkCommand extends AmplifyCommand with GlobOptions {
 
  /// Generates the SDK for [package].
  Future<void> _generateForPackage(PackageInfo package) async {
+ if (package.name == 'aws_common') {
+ return _generateAwsConfig(package);
+ }
  final configFile = File(p.join(package.path, 'sdk.yaml'));
  if (!await configFile.exists()) {
  return;
@@ -275,6 +280,112 @@ class GenerateSdkCommand extends AmplifyCommand with GlobOptions {
  }
  }
 
+ /// Generates common AWS configuration files, e.g. `aws_service.dart`.
+ Future<void> _generateAwsConfig(PackageInfo awsCommon) async {
+ logger.info('Generating AWS configuration files...');
+ const classDocs = '''
+ /// The enumeration of AWS services.
+ /// 
+ /// This enumeration is used to configure the SigV4 signer. To use a service
+ /// that is not listed here, call [AWSService.new] directly.''';
+ final builder = LibraryBuilder();
+ final awsService = ClassBuilder()
+ ..name = 'AWSService'
+ ..docs.add(classDocs)
+ ..constructors.add(
+ Constructor(
+ (c) => c
+ ..constant = true
+ ..docs.add(
+ '/// Creates a new [AWSService] instance which can be passed to a SigV4 signer.',
+ )
+ ..requiredParameters.addAll([
+ Parameter(
+ (p) => p
+ ..toThis = true
+ ..name = 'service',
+ )
+ ]),
+ ),
+ )
+ ..fields.addAll([
+ Field(
+ (f) => f
+ ..modifier = FieldModifier.final$
+ ..docs.add('/// The SigV4 service name, used in signing.')
+ ..name = 'service'
+ ..type = refer('String'),
+ )
+ ]);
+
+ final modelsDir = await _modelsDirForRef('master');
+ final models = modelsDir.list().whereType<File>();
+ final services = <Field>[];
+ await for (final model in models) {
+ final astJson = await model.readAsString();
+ final ast = parseAstJson(astJson);
+ final serviceShape = ast.shapes.values.whereType<ServiceShape>().single;
+ final sigV4Trait = serviceShape.getTrait<SigV4Trait>();
+ final serviceTrait = serviceShape.expectTrait<ServiceTrait>();
+ final serviceName = serviceTrait.sdkId.camelCase;
+ final sigV4Service = sigV4Trait?.name;
+ if (sigV4Service == null) {
+ logger.warn('Skipping $serviceName (no SigV4 service name)');
+ continue;
+ }
+ final title = serviceShape.getTrait<TitleTrait>()?.value;
+ logger.debug('Found AWS service "$serviceName"');
+ services.add(
+ Field(
+ (f) => f
+ ..static = true
+ ..modifier = FieldModifier.constant
+ ..docs.addAll([if (title != null) '/// $title'])
+ ..name = serviceName
+ ..assignment = refer('AWSService').constInstance([
+ literalString(sigV4Service),
+ ]).code,
+ ),
+ );
+ }
+
+ awsService.fields.addAll(
+ services..sort((a, b) => a.name.compareTo(b.name)),
+ );
+ builder.body.add(awsService.build());
+
+ final library = builder.build();
+ final emitter = DartEmitter(
+ allocator: Allocator(),
+ orderDirectives: true,
+ useNullSafetySyntax: true,
+ );
+ final code = '''
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// Generated with `aft generate sdk`. Do not modify by hand.
+
+${library.accept(emitter)}
+''';
+
+ final output = File(
+ p.join(
+ awsCommon.path,
+ 'lib',
+ 'src',
+ 'config',
+ 'aws_service.dart',
+ ),
+ );
+ await output.writeAsString(code);
+ await Process.run(
+ 'dart',
+ ['format', output.path],
+ workingDirectory: awsCommon.path,
+ );
+ }
+
  @override
  Future<void> run() async {
  await super.run();

packages/aft/pubspec.yaml

@@ -14,6 +14,7 @@ dependencies:
  built_value: ">=8.6.0 <8.7.0"
  checked_yaml: ^2.0.0
  cli_util: ^0.3.5
+ code_builder: 4.5.0
  collection: ^1.16.0
  file: ^7.0.0
  git: ^2.0.0

packages/aws_common/lib/src/config/aws_service.dart

@@ -1,11 +1,14 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-/// {@template aws_common.aws_service}
-/// Enumeration of AWS services.
-/// {@endtemplate}
-final class AWSService {
- /// {@macro aws_common.aws_service}
+// Generated with `aft generate sdk`. Do not modify by hand.
+
+/// The enumeration of AWS services.
+///
+/// This enumeration is used to configure the SigV4 signer. To use a service
+/// that is not listed here, call [AWSService.new] directly.
+class AWSService {
+ /// Creates a new [AWSService] instance which can be passed to a SigV4 signer.
  const AWSService(this.service);
 
  /// The SigV4 service name, used in signing.
@@ -53,6 +56,9 @@ final class AWSService {
  /// AWS AppConfig Data
  static const appConfigData = AWSService('appconfig');
 
+ /// AppFabric
+ static const appFabric = AWSService('appfabric');
+
  /// Amazon AppIntegrations Service
  static const appIntegrations = AWSService('app-integrations');