Support records

dwds/lib/src/debugging/classes.dart

@@ -76,7 +76,8 @@ class ClassHelper extends Domain {
 
     if (libraryUri == null || classId == null || className == null) return null;
 
-    final rawName = className.split('<').first;
+    var rawName = className.split('<').first;
+    if (rawName.startsWith('RecordType(')) rawName = 'Record';
     final expression = '''
     (function() {
       ${globalLoadStrategy.loadLibrarySnippet(libraryUri)}

dwds/lib/src/debugging/instance.dart

@@ -125,6 +125,9 @@ class InstanceHelper extends Domain {
     } else if (metaData.isSystemMap) {
       return await _mapInstanceFor(
           classRef, remoteObject, properties, offset, count);
+    } else if (metaData.isRecord) {
+      return await _recordInstanceFor(
+          classRef, remoteObject, properties, offset, count);
     } else {
       return await _plainInstanceFor(classRef, remoteObject, properties);
     }
@@ -152,6 +155,7 @@ class InstanceHelper extends Domain {
   Future<BoundField> _fieldFor(Property property, ClassRef classRef) async {
     final instance = await _instanceRefForRemote(property.value);
     return BoundField(
+        name: property.name,
         decl: FieldRef(
           // TODO(grouma) - Convert JS name to Dart.
           name: property.name,
@@ -297,6 +301,79 @@ class InstanceHelper extends Domain {
       ..count = (numberOfProperties == length) ? null : numberOfProperties;
   }
 
+  /// The associations for a Dart Map or IdentityMap.
+  Future<List<MapAssociation>> _recordAssociations(
+      RemoteObject map, int? offset, int? count) async {
+    // We do this in in awkward way because we want the keys and values, but we
+    // can't return things by value or some Dart objects will come back as
+    // values that we need to be RemoteObject, e.g. a List of int.
+    final expression = '''
+      function() {
+        var sdkUtils = ${globalLoadStrategy.loadModuleSnippet}('dart_sdk').dart;
+        var shape = sdkUtils.dloadRepl(this, "shape");
+        var positionals = sdkUtils.dloadRepl(shape, "positionals");
+        var names = new Array();
+        var named = sdkUtils.dloadRepl(shape, "named");
+        for (var i = 0; i < positionals; i++) {
+          names.push(i);
+        }
+        for (var name in named) {
+          names.push(name);
+        }
+
+        var values = sdkUtils.dloadRepl(this, "values");
+        values = sdkUtils.dsendRepl(values, "toList", []);
+
+        return {
+          names: names,
+          values: values
+        };
+      }
+    ''';
+    final keysAndValues = await inspector.jsCallFunctionOn(map, expression, []);
+    final keys = await inspector.loadField(keysAndValues, 'names');
+    final values = await inspector.loadField(keysAndValues, 'values');
+    final keysInstance = await instanceFor(keys, offset: offset, count: count);
+    final valuesInstance =
+        await instanceFor(values, offset: offset, count: count);
+    final associations = <MapAssociation>[];
+    final keyElements = keysInstance?.elements;
+    final valueElements = valuesInstance?.elements;
+    if (keyElements != null && valueElements != null) {
+      Map.fromIterables(keyElements, valueElements).forEach((key, value) {
+        associations.add(MapAssociation(key: key, value: value));
+      });
+    }
+    return associations;
+  }
+
+  /// Create a Map instance with class [classRef] from [remoteObject].
+  Future<Instance?> _recordInstanceFor(
+      ClassRef classRef,
+      RemoteObject remoteObject,
+      List<Property> _,
+      int? offset,
+      int? count) async {
+    final objectId = remoteObject.objectId;
+    if (objectId == null) return null;
+    // Maps are complicated, do an eval to get keys and values.
+    final associations = await _recordAssociations(remoteObject, offset, count);
+    final length = (offset == null && count == null)
+        ? associations.length
+        : (await instanceRefFor(remoteObject))?.length;
+    return Instance(
+        identityHashCode: remoteObject.objectId.hashCode,
+        kind: InstanceKind.kRecord,
+        id: objectId,
+        classRef: classRef)
+      ..length = length
+      ..offset = offset
+      ..count = (associations.length == length) ? null : associations.length
+      ..fields = associations
+          .map((e) => BoundField(name: e.key.valueAsString, value: e.value))
+          .toList();
+  }
+
   /// Return the value of the length attribute from [properties], if present.
   ///
   /// This is only applicable to Lists or Maps, where we expect a length

dwds/lib/src/debugging/metadata/class.dart

@@ -10,22 +10,37 @@ import '../../debugging/remote_debugger.dart';
 import '../../loaders/strategy.dart';
 import '../../services/chrome_debug_exception.dart';
 
+const _dartCoreLibrary = 'dart:core';
+
 /// A hard-coded ClassRef for the Closure class.
-final classRefForClosure = classRefFor('dart:core', 'Closure');
+final classRefForClosure = classRefFor(_dartCoreLibrary, 'Closure');
 
 /// A hard-coded ClassRef for the String class.
-final classRefForString = classRefFor('dart:core', InstanceKind.kString);
+final classRefForString = classRefFor(_dartCoreLibrary, InstanceKind.kString);
 
 /// A hard-coded ClassRef for a (non-existent) class called Unknown.
-final classRefForUnknown = classRefFor('dart:core', 'Unknown');
+final classRefForUnknown = classRefFor(_dartCoreLibrary, 'Unknown');
+
+///  A hard-coded LibraryRef for a a dart:core library.
+final libraryRefForCore = LibraryRef(
+  id: _dartCoreLibrary,
+  name: _dartCoreLibrary,
+  uri: _dartCoreLibrary,
+);
+
+/// Returns a [LibraryRef] for the provided library ID and class name.
+LibraryRef libraryRefFor(String libraryId) => LibraryRef(
+      id: libraryId,
+      name: libraryId,
+      uri: libraryId,
+    );
 
 /// Returns a [ClassRef] for the provided library ID and class name.
-ClassRef classRefFor(String? libraryId, String? name) => ClassRef(
-    id: 'classes|$libraryId|$name',
-    name: name,
-    library: libraryId == null
-        ? null
-        : LibraryRef(id: libraryId, name: libraryId, uri: libraryId));
+ClassRef classRefFor(String libraryId, String? name) => ClassRef(
+      id: 'classes|$libraryId|$name',
+      name: name,
+      library: libraryRefFor(libraryId),
+    );
 
 /// Meta data for a remote Dart class in Chrome.
 class ClassMetaData {
@@ -44,12 +59,15 @@ class ClassMetaData {
   final String? dartName;
 
   /// The library identifier, which is the URI of the library.
-  final String? libraryId;
+  final String libraryId;
 
   factory ClassMetaData(
       {Object? jsName, Object? libraryId, Object? dartName, Object? length}) {
-    return ClassMetaData._(jsName as String?, libraryId as String?,
-        dartName as String?, int.tryParse('$length'));
+    return ClassMetaData._(
+        jsName as String?,
+        libraryId as String? ?? _dartCoreLibrary,
+        dartName as String?,
+        int.tryParse('$length'));
   }
 
   ClassMetaData._(this.jsName, this.libraryId, this.dartName, this.length);
@@ -106,4 +124,7 @@ class ClassMetaData {
 
   /// True if this class refers to system Lists, which are treated specially.
   bool get isSystemList => jsName == 'JSArray';
+
+  /// True if this class refers to a record type.
+  bool get isRecord => jsName?.startsWith('RecordType(') ?? false;
 }

dwds/test/fixtures/context.dart

@@ -168,7 +168,8 @@ class TestContext {
     required this.nullSafety,
   }) {
     // Verify that the test fixtures package matches the null-safety mode:
-    final isSoundPackage = packageName.toLowerCase().contains('sound');
+    final isSoundPackage = packageName.toLowerCase().contains('sound') ||
+        packageName.toLowerCase().contains('experiment');
     assert(nullSafety == NullSafety.sound ? isSoundPackage : !isSoundPackage);
     // Verify that the web assets path has no starting slash:
     assert(!webAssetsPath.startsWith('/'));
@@ -199,6 +200,7 @@ class TestContext {
     bool launchChrome = true,
     bool isFlutterApp = false,
     bool isInternalBuild = false,
+    List<String> experiments = const <String>[],
   }) async {
     // Generate missing SDK assets if needed.
     final sdkConfigurationProvider =
@@ -265,6 +267,8 @@ class TestContext {
                 'build_web_compilers|ddc=generate-full-dill=true',
               ],
               '--verbose',
+              for (var experiment in experiments)
+                '--enable-experiment=$experiment',
             ];
             _daemonClient =
                 await connectClient(workingDirectory, options, (log) {
@@ -293,6 +297,7 @@ class TestContext {
                 port,
                 verbose: verboseCompiler,
                 sdkConfigurationProvider: sdkConfigurationProvider,
+                experiments: experiments,
               );
               expressionCompiler = ddcService;
             }
@@ -328,6 +333,7 @@ class TestContext {
               'org-dartlang-app',
               outputDir.path,
               nullSafety == NullSafety.sound,
+              experiments,
               verboseCompiler,
             );
 

dwds/test/records_test.dart

@@ -0,0 +1,136 @@
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+@TestOn('vm')
+@Timeout(Duration(minutes: 2))
+
+import 'package:collection/collection.dart';
+import 'package:dwds/src/connections/debug_connection.dart';
+import 'package:dwds/src/services/chrome_proxy_service.dart';
+import 'package:test/test.dart';
+import 'package:vm_service/vm_service.dart';
+
+import 'fixtures/context.dart';
+import 'fixtures/logging.dart';
+
+class TestSetup {
+  TestContext context;
+
+  TestSetup.sound()
+      : context = TestContext.withSoundNullSafety(
+          packageName: '_experiment',
+          webAssetsPath: 'web',
+          dartEntryFileName: 'main.dart',
+          htmlEntryFileName: 'index.html',
+        );
+
+  ChromeProxyService get service =>
+      fetchChromeProxyService(context.debugConnection);
+}
+
+void main() async {
+  // Enable verbose logging for debugging.
+  final debug = true;
+
+  final setup = TestSetup.sound();
+  final context = setup.context;
+
+  Future<void> onBreakPoint(String isolate, ScriptRef script,
+      String breakPointId, Future<void> Function() body) async {
+    Breakpoint? bp;
+    try {
+      final line =
+          await context.findBreakpointLine(breakPointId, isolate, script);
+      bp = await setup.service
+          .addBreakpointWithScriptUri(isolate, script.uri!, line);
+      await body();
+    } finally {
+      // Remove breakpoint so it doesn't impact other tests or retries.
+      if (bp != null) {
+        await setup.service.removeBreakpoint(isolate, bp.id!);
+      }
+    }
+  }
+
+  for (var compilationMode in [CompilationMode.frontendServer]) {
+    group('$compilationMode |', () {
+      setUpAll(() async {
+        setCurrentLogWriter(debug: debug);
+      });
+
+      group('shared context with evaluation |', () {
+        setUpAll(() async {
+          setCurrentLogWriter(debug: debug);
+          await context.setUp(
+            compilationMode: compilationMode,
+            enableExpressionEvaluation: true,
+            verboseCompiler: debug,
+            experiments: ['records'],
+          );
+        });
+
+        tearDownAll(() async {
+          await context.tearDown();
+        });
+
+        setUp(() => setCurrentLogWriter(debug: debug));
+
+        group('evaluateInFrame |', () {
+          late String isolateId;
+          late ScriptRef mainScript;
+          late Stream<Event> stream;
+
+          setUp(() async {
+            setCurrentLogWriter(debug: debug);
+            final vm = await setup.service.getVM();
+            isolateId = vm.isolates!.first.id!;
+            final scripts = await setup.service.getScripts(isolateId);
+
+            await setup.service.streamListen('Debug');
+            stream = setup.service.onEvent('Debug');
+
+            mainScript = scripts.scripts!
+                .firstWhere((each) => each.uri!.contains('main.dart'));
+          });
+
+          tearDown(() async {
+            await setup.service.resume(isolateId);
+          });
+
+          test('can evaluate and display records', () async {
+            await onBreakPoint(isolateId, mainScript, 'printLocal', () async {
+              final event = await stream.firstWhere(
+                  (event) => event.kind == EventKind.kPauseBreakpoint);
+
+              final result = await setup.service
+                  .evaluateInFrame(isolateId, event.topFrame!.index!, 'record');
+
+              //  Actual: InstanceRef:<[InstanceRef id: 5614429716467540672.1.54, kind: PlainInstance, identityHashCode: 912649884, classRef: [ClassRef id: classes|null|RecordType(bool, int), name: RecordType(bool, int), library: null]]>
+              expect(result, isA<InstanceRef>());
+
+              final instanceRef = result as InstanceRef;
+              final instance = await setup.service
+                  .getObject(isolateId, instanceRef.id!) as Instance;
+
+              expect(instance.kind, InstanceKind.kRecord);
+
+              final classRef = instance.classRef!;
+              expect(classRef, isNotNull);
+              expect(classRef.name, 'RecordType(bool, int)');
+
+              final fieldNames = instance.fields!
+                  .map((boundField) => boundField.name)
+                  .whereNotNull()
+                  .toList();
+              expect(fieldNames, [
+                r'$0',
+                r'$1',
+              ]);
+            });
+          });
+        });
+      });
+    });
+  }
+}

fixtures/_experiment/pubspec.yaml

@@ -0,0 +1,20 @@
+# This code is for testing that the debugger works with weak null-safety
+# so we should not migrate it to null-safety.
+# TODO(elliette): Delete this directory post Dart 3.0 (when we no longer
+# support weak null-safety).
+name: _experiment
+version: 1.0.0
+description: >-
+  A fake package used for testing experimental language features.
+publish_to: none
+
+environment:
+  sdk: ">=3.0.0-134.0.dev<4.0.0"
+
+dependencies:
+  intl: ^0.17.0
+  path: ^1.8.2
+
+dev_dependencies:
+  build_runner: ^2.4.0
+  build_web_compilers: ^4.0.0

fixtures/_experiment/web/index.html

@@ -0,0 +1,7 @@
+<html>
+
+<head>
+  <script defer src="main.dart.js"></script>
+</head>
+
+</html>