Document highlights feature

Author: wkillerud

pkgs/sass_language_server/lib/src/language_server.dart

@@ -174,6 +174,7 @@ class LanguageServer {
 
         var serverCapabilities = ServerCapabilities(
           definitionProvider: Either2.t1(true),
+          documentHighlightProvider: Either2.t1(true),
           documentLinkProvider: DocumentLinkOptions(resolveProvider: false),
           documentSymbolProvider: Either2.t1(true),
           referencesProvider: Either2.t1(true),
@@ -265,6 +266,28 @@ class LanguageServer {
         }
       });
 
+      _connection.onDocumentHighlight((params) async {
+        try {
+          var document = _documents.get(params.textDocument.uri);
+          if (document == null) return [];
+
+          var configuration = _getLanguageConfiguration(document);
+          if (configuration.highlights.enabled) {
+            if (initialScan != null) {
+              await initialScan;
+            }
+
+            var result = _ls.findDocumentHighlights(document, params.position);
+            return result;
+          } else {
+            return [];
+          }
+        } on Exception catch (e) {
+          _log.debug(e.toString());
+          return [];
+        }
+      });
+
       _connection.onDocumentLinks((params) async {
         try {
           var document = _documents.get(params.textDocument.uri);

pkgs/sass_language_services/lib/src/configuration/language_configuration.dart

@@ -4,43 +4,26 @@ class FeatureConfiguration {
   FeatureConfiguration({required this.enabled});
 }
 
-class DefinitionConfiguration extends FeatureConfiguration {
-  DefinitionConfiguration({required super.enabled});
-}
-
-class DocumentSymbolsConfiguration extends FeatureConfiguration {
-  DocumentSymbolsConfiguration({required super.enabled});
-}
-
-class DocumentLinksConfiguration extends FeatureConfiguration {
-  DocumentLinksConfiguration({required super.enabled});
-}
-
-class ReferencesConfiguration extends FeatureConfiguration {
-  ReferencesConfiguration({required super.enabled});
-}
-
-class WorkspaceSymbolsConfiguration extends FeatureConfiguration {
-  WorkspaceSymbolsConfiguration({required super.enabled});
-}
-
 class LanguageConfiguration {
-  late final DefinitionConfiguration definition;
-  late final DocumentSymbolsConfiguration documentSymbols;
-  late final DocumentLinksConfiguration documentLinks;
-  late final ReferencesConfiguration references;
-  late final WorkspaceSymbolsConfiguration workspaceSymbols;
+  late final FeatureConfiguration definition;
+  late final FeatureConfiguration highlights;
+  late final FeatureConfiguration documentSymbols;
+  late final FeatureConfiguration documentLinks;
+  late final FeatureConfiguration references;
+  late final FeatureConfiguration workspaceSymbols;
 
   LanguageConfiguration.from(dynamic config) {
-    definition = DefinitionConfiguration(
+    definition = FeatureConfiguration(
         enabled: config?['definition']?['enabled'] as bool? ?? true);
-    documentSymbols = DocumentSymbolsConfiguration(
+    documentSymbols = FeatureConfiguration(
         enabled: config?['documentSymbols']?['enabled'] as bool? ?? true);
-    documentLinks = DocumentLinksConfiguration(
+    documentLinks = FeatureConfiguration(
         enabled: config?['documentLinks']?['enabled'] as bool? ?? true);
-    references = ReferencesConfiguration(
+    highlights = FeatureConfiguration(
+        enabled: config?['highlights']?['enabled'] as bool? ?? true);
+    references = FeatureConfiguration(
         enabled: config?['references']?['enabled'] as bool? ?? true);
-    workspaceSymbols = WorkspaceSymbolsConfiguration(
+    workspaceSymbols = FeatureConfiguration(
         enabled: config?['workspaceSymbols']?['enabled'] as bool? ?? true);
   }
 }

pkgs/sass_language_services/lib/src/features/document_highlights/document_highlights_feature.dart

@@ -0,0 +1,60 @@
+import 'package:lsp_server/lsp_server.dart' as lsp;
+import 'package:sass_api/sass_api.dart' as sass;
+import 'package:sass_language_services/sass_language_services.dart';
+import 'package:sass_language_services/src/features/find_references/find_references_visitor.dart';
+import 'package:sass_language_services/src/utils/sass_lsp_utils.dart';
+
+import '../go_to_definition/scope_visitor.dart';
+import '../go_to_definition/scoped_symbols.dart';
+import '../language_feature.dart';
+import '../node_at_offset_visitor.dart';
+
+class DocumentHighlightsFeature extends LanguageFeature {
+  DocumentHighlightsFeature({required super.ls});
+
+  List<lsp.DocumentHighlight> findDocumentHighlights(
+      TextDocument document, lsp.Position position) {
+    var stylesheet = ls.parseStylesheet(document);
+    // Find the node whose definition we're looking for.
+    var offset = document.offsetAt(position);
+    var visitor = NodeAtOffsetVisitor(offset);
+    var node = stylesheet.accept(visitor);
+    if (node == null || node is sass.Stylesheet) {
+      return [];
+    }
+
+    var name = getNodeName(node);
+    if (name == null) {
+      return [];
+    }
+    var kind = getNodeReferenceKind(node);
+
+    var symbols = ScopedSymbols(
+      stylesheet,
+      document.languageId == 'sass' ? Dialect.indented : Dialect.scss,
+    );
+    var symbol = symbols.findSymbolFromNode(node);
+
+    var result = <lsp.DocumentHighlight>[];
+    var references = FindReferencesVisitor(document, name);
+    for (var reference in references.candidates) {
+      if (symbol != null) {
+        if (symbol.referenceKind == reference.kind &&
+            symbol.name == reference.name &&
+            isSameRange(symbol.range, reference.location.range)) {
+          result.add(
+            lsp.DocumentHighlight(range: reference.location.range),
+          );
+        }
+      } else if (kind != null &&
+          reference.kind == kind &&
+          reference.name == name) {
+        result.add(
+          lsp.DocumentHighlight(range: reference.location.range),
+        );
+      }
+    }
+
+    return result;
+  }
+}

pkgs/sass_language_services/lib/src/features/find_references/find_references_feature.dart

@@ -4,6 +4,7 @@ import 'package:sass_language_services/src/features/find_references/find_referen
 import 'package:sass_language_services/src/features/go_to_definition/go_to_definition_feature.dart';
 
 import '../../sass/sass_data.dart';
+import '../../utils/sass_lsp_utils.dart';
 import '../go_to_definition/definition.dart';
 import 'reference.dart';
 
@@ -89,7 +90,7 @@ class FindReferencesFeature extends GoToDefinitionFeature {
             continue;
           }
 
-          var candidateIsDefinition = _isSameLocation(
+          var candidateIsDefinition = isSameLocation(
             candidate.location,
             definition.location!,
           );
@@ -109,7 +110,7 @@ class FindReferencesFeature extends GoToDefinitionFeature {
 
           if (candidateDefinition != null &&
               candidateDefinition.location != null) {
-            if (_isSameLocation(
+            if (isSameLocation(
               candidateDefinition.location!,
               definition.location!,
             )) {
@@ -125,12 +126,4 @@ class FindReferencesFeature extends GoToDefinitionFeature {
 
     return (definition: definition, references: references);
   }
-
-  bool _isSameLocation(lsp.Location a, lsp.Location b) {
-    return a.uri.toString() == b.uri.toString() &&
-        a.range.start.line == b.range.start.line &&
-        a.range.start.character == b.range.start.character &&
-        a.range.end.line == b.range.end.line &&
-        a.range.end.character == b.range.end.character;
-  }
 }

pkgs/sass_language_services/lib/src/language_services.dart

@@ -1,6 +1,7 @@
 import 'package:lsp_server/lsp_server.dart' as lsp;
 import 'package:sass_api/sass_api.dart' as sass;
 import 'package:sass_language_services/sass_language_services.dart';
+import 'package:sass_language_services/src/features/document_highlights/document_highlights_feature.dart';
 import 'package:sass_language_services/src/features/find_references/find_references_feature.dart';
 import 'package:sass_language_services/src/features/go_to_definition/go_to_definition_feature.dart';
 
@@ -17,6 +18,7 @@ class LanguageServices {
   LanguageServerConfiguration configuration =
       LanguageServerConfiguration.create(null);
 
+  late final DocumentHighlightsFeature _documentHighlights;
   late final DocumentLinksFeature _documentLinks;
   late final DocumentSymbolsFeature _documentSymbols;
   late final GoToDefinitionFeature _goToDefinition;
@@ -27,6 +29,7 @@ class LanguageServices {
     required this.clientCapabilities,
     required this.fs,
   }) : cache = LanguageServicesCache() {
+    _documentHighlights = DocumentHighlightsFeature(ls: this);
     _documentLinks = DocumentLinksFeature(ls: this);
     _documentSymbols = DocumentSymbolsFeature(ls: this);
     _goToDefinition = GoToDefinitionFeature(ls: this);
@@ -38,6 +41,11 @@ class LanguageServices {
     this.configuration = configuration;
   }
 
+  List<lsp.DocumentHighlight> findDocumentHighlights(
+      TextDocument document, lsp.Position position) {
+    return _documentHighlights.findDocumentHighlights(document, position);
+  }
+
   Future<List<StylesheetDocumentLink>> findDocumentLinks(
       TextDocument document) {
     return _documentLinks.findDocumentLinks(document);

pkgs/sass_language_services/lib/src/utils/sass_lsp_utils.dart

@@ -51,3 +51,14 @@ bool isInRange({required lsp.Position position, required lsp.Range range}) {
       range.end.line >= position.line &&
       range.end.character >= position.character;
 }
+
+bool isSameLocation(lsp.Location a, lsp.Location b) {
+  return a.uri.toString() == b.uri.toString() && isSameRange(a.range, b.range);
+}
+
+bool isSameRange(lsp.Range a, lsp.Range b) {
+  return a.start.line == b.start.line &&
+      a.start.character == b.start.character &&
+      a.end.line == b.end.line &&
+      a.end.character == b.end.character;
+}