Support Set inspection in DWDS (#2024)

Author: elliette

dwds/CHANGELOG.md

@@ -3,6 +3,7 @@
 - Fix failure to map JS exceptions to dart. - [#2004](https://github.com/dart-lang/webdev/pull/2004)
 - Fix for listening to custom streams. - [#2011](https://github.com/dart-lang/webdev/pull/2011)
 - Handle unexpected extension debugger disconnect events without crashing the app - [#2021](https://github.com/dart-lang/webdev/pull/2021)
+- Support `Set` inspection. - [#2024](https://github.com/dart-lang/webdev/pull/2024)
 
 ## 18.0.0
 

dwds/lib/src/debugging/instance.dart

@@ -128,6 +128,14 @@ class InstanceHelper extends Domain {
     } else if (metaData.isRecord) {
       return await _recordInstanceFor(classRef, remoteObject,
           offset: offset, count: count, length: metaData.length);
+    } else if (metaData.isSet) {
+      return await _setInstanceFor(
+        classRef,
+        remoteObject,
+        offset: offset,
+        count: count,
+        length: metaData.length,
+      );
     } else if (metaData.isNativeError) {
       return await _plainInstanceFor(classRefForNativeJsError, remoteObject,
           offset: offset, count: count, length: metaData.length);
@@ -376,7 +384,7 @@ class InstanceHelper extends Domain {
   ///
   /// If [offset] is `null`, assumes 0 offset.
   /// If [count] is `null`, return all fields starting from the offset.
-  Future<List<BoundField>> _recordFields(RemoteObject map,
+  Future<List<BoundField>> _recordFields(RemoteObject record,
       {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
@@ -398,7 +406,7 @@ class InstanceHelper extends Domain {
         };
       }
     ''';
-    final result = await inspector.jsCallFunctionOn(map, expression, []);
+    final result = await inspector.jsCallFunctionOn(record, expression, []);
     final positionalCountObject =
         await inspector.loadField(result, 'positionalCount');
     if (positionalCountObject == null || positionalCountObject.value is! int) {
@@ -494,6 +502,51 @@ class InstanceHelper extends Domain {
       ..fields = fields;
   }
 
+  Future<Instance?> _setInstanceFor(
+    ClassRef classRef,
+    RemoteObject remoteObject, {
+    int? offset,
+    int? count,
+    int? length,
+  }) async {
+    final objectId = remoteObject.objectId;
+    if (objectId == null) return null;
+
+    final expression = '''
+      function() {
+        const sdkUtils = ${globalLoadStrategy.loadModuleSnippet}('dart_sdk').dart;
+        const jsSet = sdkUtils.dloadRepl(this, "_map");
+        const entries = [...jsSet.values()];
+        return {
+          entries: entries
+        };
+      }
+    ''';
+
+    final result =
+        await inspector.jsCallFunctionOn(remoteObject, expression, []);
+    final entriesObject = await inspector.loadField(result, 'entries');
+    final entriesInstance =
+        await instanceFor(entriesObject, offset: offset, count: count);
+    final elements = entriesInstance?.elements ?? [];
+
+    final setInstance = Instance(
+        identityHashCode: remoteObject.objectId.hashCode,
+        kind: InstanceKind.kSet,
+        id: objectId,
+        classRef: classRef)
+      ..length = length
+      ..elements = elements;
+    if (offset != null && offset > 0) {
+      setInstance.offset = offset;
+    }
+    if (length != null && elements.length < length) {
+      setInstance.count = elements.length;
+    }
+
+    return setInstance;
+  }
+
   /// Return the available count of elements in the requested range.
   /// Return `null` if the range includes the whole object.
   /// [count] is the range length requested by the `getObject` call.
@@ -633,6 +686,14 @@ class InstanceHelper extends Domain {
               classRef: metaData.classRef)
             ..length = metaData.length;
         }
+        if (metaData.isSet) {
+          return InstanceRef(
+              kind: InstanceKind.kSet,
+              id: objectId,
+              identityHashCode: remoteObject.objectId.hashCode,
+              classRef: metaData.classRef)
+            ..length = metaData.length;
+        }
         if (metaData.isNativeError) {
           return InstanceRef(
               kind: InstanceKind.kPlainInstance,

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

@@ -196,6 +196,8 @@ class ClassMetaData {
   /// True if this class refers to system Lists, which are treated specially.
   bool get isSystemList => jsName == 'JSArray';
 
+  bool get isSet => jsName == '_HashSet';
+
   /// True if this class refers to a function type.
   bool isFunction;