Connect up augmentations from macro output through to host. (#21)

pkgs/_macro_client/lib/macro_client.dart

@@ -14,7 +14,11 @@ import 'package:macro_service/macro_service.dart';
 /// TODO(davidmorgan): split to multpile implementations depending on
 /// transport used to connect to host.
 class MacroClient {
-  MacroClient._(Iterable<Macro> macros, Socket socket) {
+  final RemoteMacroHost host = RemoteMacroHost();
+  final Iterable<Macro> macros;
+  final Socket socket;
+
+  MacroClient._(this.macros, this.socket) {
     // TODO(davidmorgan): negotiation about protocol version goes here.
 
     // Tell the host which macros are in this bundle.
@@ -24,6 +28,11 @@ class MacroClient {
       // switch to binary.
       socket.writeln(json.encode(request.node));
     }
+
+    const Utf8Decoder()
+        .bind(socket)
+        .transform(const LineSplitter())
+        .listen(_handleRequest);
   }
 
   /// Runs [macros] for the host at [endpoint].
@@ -32,4 +41,22 @@ class MacroClient {
     final socket = await Socket.connect('localhost', endpoint.port);
     return MacroClient._(macros, socket);
   }
+
+  void _handleRequest(String request) async {
+    // TODO(davidmorgan): support more than one request type.
+    final augmentRequest =
+        AugmentRequest.fromJson(json.decode(request) as Map<String, Object?>);
+    // TODO(davidmorgan): support multiple macros.
+    final response = await macros.single.augment(host, augmentRequest);
+    _send(response.node);
+  }
+
+  void _send(Map<String, Object?> node) {
+    // TODO(davidmorgan): currently this is JSON with one request per line,
+    // switch to binary.
+    socket.writeln(json.encode(node));
+  }
 }
+
+/// [Host] that is connected to a remote macro host.
+class RemoteMacroHost implements Host {}

pkgs/_macro_client/pubspec.yaml

@@ -14,5 +14,6 @@ dependencies:
 
 dev_dependencies:
   _test_macros: any
+  async: ^2.11.0
   dart_flutter_team_lints: ^3.0.0
   test: ^1.25.0

pkgs/_macro_client/test/macro_client_test.dart

@@ -3,10 +3,12 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:_macro_client/macro_client.dart';
 import 'package:_test_macros/declare_x_macro.dart';
+import 'package:async/async.dart';
 import 'package:macro_service/macro_service.dart';
 import 'package:test/test.dart';
 
@@ -23,5 +25,24 @@ void main() {
       expect(
           serverSocket.first.timeout(const Duration(seconds: 10)), completes);
     });
+
+    test('sends requests to and from macros', () async {
+      final serverSocket = await ServerSocket.bind('localhost', 0);
+
+      unawaited(MacroClient.run(
+          endpoint: HostEndpoint(port: serverSocket.port),
+          macros: [DeclareXImplementation()]));
+
+      final socket = await serverSocket.first;
+
+      final responses = StreamQueue(
+          const Utf8Decoder().bind(socket).transform(const LineSplitter()));
+      final descriptionResponse = await responses.next;
+      expect(descriptionResponse, '{"macroDescription":{"runsInPhases":[2]}}');
+
+      socket.writeln(json.encode(AugmentRequest(phase: 2)));
+      final augmentResponse = await responses.next;
+      expect(augmentResponse, '{"augmentations":[{"code":"int get x => 3;"}]}');
+    });
   });
 }

pkgs/_macro_host/lib/macro_host.dart

@@ -24,6 +24,10 @@ class MacroHost implements MacroService {
   // lifecycle state.
   Completer<Set<int>>? _macroPhases;
 
+  // TODO(davidmorgan): actually match up requests and responses instead of
+  // this hack.
+  Completer<AugmentResponse>? _responseCompleter;
+
   MacroHost._(this.macroServer, this.services) {
     services.services.insert(0, this);
   }
@@ -61,9 +65,31 @@ class MacroHost implements MacroService {
     return _macroPhases!.future;
   }
 
+  /// Sends [request] to the macro with [name].
+  Future<AugmentResponse> augment(
+      QualifiedName name, AugmentRequest request) async {
+    // TODO(davidmorgan): this just assumes the macro is running, actually
+    // track macro lifecycle.
+    macroServer.sendToMacro(name, request);
+    if (_responseCompleter != null) {
+      throw StateError('request is already pending');
+    }
+    _responseCompleter = Completer<AugmentResponse>();
+    return await _responseCompleter!.future;
+  }
+
   /// Handle requests that are for the host.
   @override
   Future<Object?> handle(Object request) async {
+    // TODO(davidmorgan): differentiate requests and responses, rather than
+    // handling as requests.
+    if (_responseCompleter != null) {
+      final augmentResponse =
+          AugmentResponse.fromJson(request as Map<String, Object?>);
+      _responseCompleter!.complete(augmentResponse);
+      _responseCompleter = null;
+      return Object();
+    }
     // TODO(davidmorgan): don't assume the type. Return `null` for types
     // that should be passed through to the service that was passed in.
     final macroStartedRequest =
@@ -72,8 +98,6 @@ class MacroHost implements MacroService {
         .complete(macroStartedRequest.macroDescription.runsInPhases.toSet());
     return MacroStartedResponse();
   }
-
-  // TODO(davidmorgan): add method here for running macro phases.
 }
 
 // TODO(davidmorgan): this is used to handle some requests in the host while

pkgs/_macro_host/test/macro_host_test.dart

@@ -21,6 +21,11 @@ void main() {
 
       expect(host.isMacro(packageConfig, macroName), true);
       expect(await host.queryMacroPhases(packageConfig, macroName), {2});
+
+      expect(
+          await host.augment(macroName, AugmentRequest(phase: 2)),
+          AugmentResponse(
+              augmentations: [Augmentation(code: 'int get x => 3;')]));
     });
   });
 }

pkgs/_macro_server/lib/macro_server.dart

@@ -2,9 +2,11 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:dart_model/dart_model.dart';
 import 'package:macro_service/macro_service.dart';
 
 /// Serves a [MacroService].
@@ -13,6 +15,9 @@ class MacroServer {
   final HostEndpoint endpoint;
   final ServerSocket serverSocket;
 
+  // TODO(davidmorgan): track which socket corresponds to which macro(s).
+  Socket? _lastSocket;
+
   MacroServer._(this.service, this.endpoint, this.serverSocket) {
     serverSocket.forEach(_handleConnection);
   }
@@ -26,7 +31,12 @@ class MacroServer {
         service, HostEndpoint(port: serverSocket.port), serverSocket);
   }
 
+  void sendToMacro(QualifiedName name, AugmentRequest request) async {
+    _lastSocket!.writeln(json.encode(request.node));
+  }
+
   void _handleConnection(Socket socket) {
+    _lastSocket = socket;
     // TODO(davidmorgan): currently this is JSON with one request per line,
     // switch to binary.
     socket

pkgs/_macro_server/pubspec.yaml

@@ -9,6 +9,7 @@ environment:
   sdk: ^3.6.0-48.0.dev
 
 dependencies:
+  dart_model: any
   macro_service: any
 
 dev_dependencies:

pkgs/_test_macros/lib/declare_x_macro.dart

@@ -2,21 +2,23 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:dart_model/dart_model.dart';
 import 'package:macro/macro.dart';
 import 'package:macro_service/macro_service.dart';
 
+/// Adds a getter `int get x` to the class.
 class DeclareX {
   const DeclareX();
 }
 
-// TODO(davidmorgan): this is a placeholder; make it do something, test it.
 class DeclareXImplementation implements Macro {
   @override
   MacroDescription get description => MacroDescription(runsInPhases: [2]);
 
   @override
   Future<AugmentResponse> augment(Host host, AugmentRequest request) async {
-    // TODO(davidmorgan): add an implementation.
-    return AugmentResponse();
+    // TODO(davidmorgan): still need to pass through the augment target.
+    return AugmentResponse(
+        augmentations: [Augmentation(code: 'int get x => 3;')]);
   }
 }

pkgs/dart_model/lib/src/dart_model.g.dart

@@ -1,9 +1,16 @@
 // This file is generated. To make changes edit schemas/*.schema.json
 // then run from the repo root: dart tool/model_generator/bin/main.dart
 
-/// An augmentation to Dart code. TODO(davidmorgan): this is a placeholder, add some data.
+/// An augmentation to Dart code. TODO(davidmorgan): this is a placeholder.
 extension type Augmentation.fromJson(Map<String, Object?> node) {
-  Augmentation() : this.fromJson({});
+  Augmentation({
+    String? code,
+  }) : this.fromJson({
+          if (code != null) 'code': code,
+        });
+
+  /// Augmentation code.
+  String get code => node['code'] as String;
 }
 
 /// A metadata annotation.

pkgs/macro_service/lib/src/macro_service.g.dart

@@ -1,6 +1,8 @@
 // This file is generated. To make changes edit schemas/*.schema.json
 // then run from the repo root: dart tool/model_generator/bin/main.dart
 
+import 'package:dart_model/dart_model.dart';
+
 /// A request to a macro to augment some code.
 extension type AugmentRequest.fromJson(Map<String, Object?> node) {
   AugmentRequest({
@@ -15,7 +17,15 @@ extension type AugmentRequest.fromJson(Map<String, Object?> node) {
 
 /// Macro's response to an [AugmentRequest]: the resulting augmentations.
 extension type AugmentResponse.fromJson(Map<String, Object?> node) {
-  AugmentResponse() : this.fromJson({});
+  AugmentResponse({
+    List<Augmentation>? augmentations,
+  }) : this.fromJson({
+          if (augmentations != null) 'augmentations': augmentations,
+        });
+
+  /// The augmentations.
+  List<Augmentation> get augmentations =>
+      (node['augmentations'] as List).cast();
 }
 
 /// A macro host server endpoint. TODO(davidmorgan): this should be a oneOf supporting different types of connection. TODO(davidmorgan): it's not clear if this belongs in this package! But, where else?

pkgs/macro_service/pubspec.yaml

@@ -8,5 +8,8 @@ resolution: workspace
 environment:
   sdk: ^3.6.0-48.0.dev
 
+dependencies:
+  dart_model: any
+
 dev_dependencies:
   dart_flutter_team_lints: ^3.0.0

schemas/dart_model.schema.json

@@ -1,14 +1,17 @@
 {
-  "$id": "https://github.com/dart-lang/macros/blob/main/schemas/dart_model.schema.json",
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "oneOf": [
     {"$ref": "#/$defs/Model"}
   ],
   "$defs": {
     "Augmentation": {
-      "description": "An augmentation to Dart code. TODO(davidmorgan): this is a placeholder, add some data.",
+      "description": "An augmentation to Dart code. TODO(davidmorgan): this is a placeholder.",
       "type": "object",
       "properties": {
+        "code": {
+          "type": "string",
+          "description": "Augmentation code."
+        }
       }
     },
     "MetadataAnnotation": {

schemas/macro_service.schema.json

@@ -1,5 +1,4 @@
 {
-  "$id": "https://github.com/dart-lang/macros/blob/main/schemas/macro_service.schema.json",
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "oneOf": [
     {"$ref": "#/$defs/AugmentRequest"},
@@ -18,7 +17,14 @@
     },
     "AugmentResponse": {
       "type": "object",
-      "description": "Macro's response to an [AugmentRequest]: the resulting augmentations."
+      "description": "Macro's response to an [AugmentRequest]: the resulting augmentations.",
+      "properties": {
+        "augmentations": {
+          "description": "The augmentations.",
+          "type": "array",
+          "items": {"$ref": "file:dart_model.schema.json#/$defs/Augmentation"}
+        }
+      }
     },
     "HostEndpoint": {
       "type": "object",

tool/dart_model_generator/lib/generate_dart_model.dart

@@ -2,10 +2,13 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:dart_style/dart_style.dart';
 import 'package:json_schema/json_schema.dart';
+// ignore: implementation_imports
+import 'package:json_schema/src/json_schema/models/ref_provider.dart';
 
 /// Generates `pkgs/dart_model/lib/src/dart_model.g.dart` from
 /// `schemas/dart_model.schema.json`, and similarly for `macro_service`.
@@ -17,18 +20,23 @@ void run() {
   File('pkgs/dart_model/lib/src/dart_model.g.dart').writeAsStringSync(
       generate(File('schemas/dart_model.schema.json').readAsStringSync()));
   File('pkgs/macro_service/lib/src/macro_service.g.dart').writeAsStringSync(
-      generate(File('schemas/macro_service.schema.json').readAsStringSync()));
+      generate(File('schemas/macro_service.schema.json').readAsStringSync(),
+          importDartModel: true));
 }
 
 /// Generates and returns code for [schemaJson].
-String generate(String schemaJson) {
+String generate(String schemaJson,
+    {bool importDartModel = false, String? dartModelJson}) {
   final result = <String>[
     '// This file is generated. To make changes edit schemas/*.schema.json',
     '// then run from the repo root: '
         'dart tool/model_generator/bin/main.dart',
     '',
+    if (importDartModel) "import 'package:dart_model/dart_model.dart';",
   ];
-  final schema = JsonSchema.create(schemaJson);
+  final schema = JsonSchema.create(schemaJson,
+      refProvider: LocalRefProvider(dartModelJson ??
+          File('schemas/dart_model.schema.json').readAsStringSync()));
   for (final def in schema.defs.entries) {
     result.add(_generateExtensionType(def.key, def.value));
   }
@@ -174,7 +182,7 @@ String _readRefNameOrType(JsonSchema schema, String key) {
   final typeSchema = schema.schemaMap![key] as Map;
   final ref = typeSchema[r'$ref'] as String?;
   if (ref != null) {
-    return ref.substring(r'#/$defs/'.length);
+    return ref.substring(ref.indexOf(r'#/$defs/') + r'#/$defs/'.length);
   } else {
     final type = typeSchema['type'] as String;
     switch (type) {
@@ -209,3 +217,26 @@ class PropertyMetadata {
       required this.type,
       this.elementTypeName});
 }
+
+/// Loads referenced schemas.
+///
+/// No need to connect to servers like the default implementation, just return
+/// the one file we know we need.
+class LocalRefProvider implements RefProvider<SyncJsonProvider> {
+  final String dartModelJson;
+
+  LocalRefProvider(this.dartModelJson);
+
+  @override
+  bool get isSync => true;
+
+  @override
+  SyncJsonProvider get provide => (String path) {
+        if (path != 'file:///dart_model.schema.json') {
+          throw UnsupportedError(
+              'This provider only loads file:///dart_model.schema.json!'
+              ' Got: $path');
+        }
+        return json.decode(dartModelJson) as Map<String, Object?>;
+      };
+}