Selection ranges (#31)

extension/test/electron/definition/selection-ranges.test.js

@@ -0,0 +1,39 @@
+const assert = require('node:assert');
+const path = require('node:path');
+const vscode = require('vscode');
+const { showFile, sleepCI } = require('../util');
+
+const stylesUri = vscode.Uri.file(
+  path.resolve(__dirname, 'fixtures', 'styles.scss')
+);
+
+before(async () => {
+  await showFile(stylesUri);
+  await sleepCI();
+});
+
+after(async () => {
+  await vscode.commands.executeCommand('workbench.action.closeAllEditors');
+});
+
+/**
+ * @param {import('vscode').Uri} documentUri
+ * @param {Array<import('vscode').Position>} positions
+ * @returns {Promise<Array<import('vscode').SelectionRange>>}
+ */
+async function getSelectionRanges(documentUri, positions) {
+  const result = await vscode.commands.executeCommand(
+    'vscode.executeSelectionRangeProvider',
+    documentUri,
+    positions
+  );
+  return result;
+}
+
+test('gets document selection ranges', async () => {
+  const [result] = await getSelectionRanges(stylesUri, [
+    new vscode.Position(7, 5),
+  ]);
+
+  assert.ok(result, 'Should have gotten selection ranges');
+});

pkgs/sass_language_server/lib/src/language_server.dart

@@ -178,6 +178,7 @@ class LanguageServer {
           documentSymbolProvider: Either2.t1(true),
           referencesProvider: Either2.t1(true),
           renameProvider: Either2.t2(RenameOptions(prepareProvider: true)),
+          selectionRangeProvider: Either3.t1(true),
           textDocumentSync: Either2.t1(TextDocumentSyncKind.Incremental),
           workspaceSymbolProvider: Either2.t1(true),
         );
@@ -432,6 +433,29 @@ class LanguageServer {
         }
       });
 
+      _connection.onSelectionRanges((params) async {
+        try {
+          var document = _documents.get(params.textDocument.uri);
+          if (document == null) {
+            return [];
+          }
+
+          var configuration = _getLanguageConfiguration(document);
+          if (configuration.selectionRanges.enabled) {
+            var result = _ls.getSelectionRanges(
+              document,
+              params.positions,
+            );
+            return result;
+          } else {
+            return [];
+          }
+        } on Exception catch (e) {
+          _log.debug(e.toString());
+          return [];
+        }
+      });
+
       // TODO: add this handler upstream
       Future<List<WorkspaceSymbol>> onWorkspaceSymbol(dynamic params) async {
         try {

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

@@ -11,6 +11,7 @@ class LanguageConfiguration {
   late final FeatureConfiguration documentLinks;
   late final FeatureConfiguration references;
   late final FeatureConfiguration rename;
+  late final FeatureConfiguration selectionRanges;
   late final FeatureConfiguration workspaceSymbols;
 
   LanguageConfiguration.from(dynamic config) {
@@ -26,6 +27,8 @@ class LanguageConfiguration {
         enabled: config?['references']?['enabled'] as bool? ?? true);
     rename = FeatureConfiguration(
         enabled: config?['rename']?['enabled'] as bool? ?? true);
+    selectionRanges = FeatureConfiguration(
+        enabled: config?['selectionRanges']?['enabled'] as bool? ?? true);
     workspaceSymbols = FeatureConfiguration(
         enabled: config?['workspaceSymbols']?['enabled'] as bool? ?? true);
   }

pkgs/sass_language_services/lib/src/features/node_at_offset_visitor.dart

@@ -21,6 +21,9 @@ class NodeAtOffsetVisitor
   /// Finds the node with the shortest span at [offset].
   NodeAtOffsetVisitor(int offset) : _offset = offset;
 
+  /// Here to allow subclasses to do something with each candidate.
+  void processCandidate(sass.AstNode node) {}
+
   sass.AstNode? _process(sass.AstNode node) {
     var nodeSpan = node.span;
     var nodeStartOffset = nodeSpan.start.offset;
@@ -30,6 +33,7 @@ class NodeAtOffsetVisitor
     if (containsOffset) {
       if (candidate == null) {
         candidate = node;
+        processCandidate(node);
       } else {
         var nodeLength = nodeEndOffset - nodeStartOffset;
         // store candidateSpan next to _candidate
@@ -38,6 +42,7 @@ class NodeAtOffsetVisitor
             candidateSpan.end.offset - candidateSpan.start.offset;
         if (nodeLength <= candidateLength) {
           candidate = node;
+          processCandidate(node);
         }
       }
     }

pkgs/sass_language_services/lib/src/features/selection_ranges/selection_ranges_feature.dart

@@ -0,0 +1,58 @@
+import 'package:lsp_server/lsp_server.dart' as lsp;
+import 'package:sass_language_services/sass_language_services.dart';
+import 'package:sass_language_services/src/features/selection_ranges/selection_ranges_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';
+
+class SelectionRangesFeature extends LanguageFeature {
+  SelectionRangesFeature({required super.ls});
+
+  List<lsp.SelectionRange> getSelectionRanges(
+      TextDocument document, List<lsp.Position> positions) {
+    var stylesheet = ls.parseStylesheet(document);
+    var symbols = ls.cache.getDocumentSymbols(document) ??
+        ScopedSymbols(
+          stylesheet,
+          document.languageId == 'sass' ? Dialect.indented : Dialect.scss,
+        );
+    ls.cache.setDocumentSymbols(document, symbols);
+
+    var result = <lsp.SelectionRange>[];
+
+    for (var position in positions) {
+      var visitor = SelectionRangesVisitor(
+        document.offsetAt(position),
+      );
+      stylesheet.accept(visitor);
+
+      var ranges = visitor.ranges;
+      lsp.SelectionRange? current;
+      for (var i = ranges.length - 1; i >= 0; i--) {
+        var range = ranges[i];
+
+        // Avoid duplicates
+        if (current != null && isSameRange(current.range, range.range)) {
+          continue;
+        }
+
+        current = lsp.SelectionRange(
+          range: range.range,
+          parent: current,
+        );
+      }
+      if (current == null) {
+        result.add(
+          lsp.SelectionRange(
+            range: lsp.Range(start: position, end: position),
+          ),
+        );
+      }
+      result.add(current!);
+    }
+
+    return result;
+  }
+}

pkgs/sass_language_services/lib/src/features/selection_ranges/selection_ranges_visitor.dart

@@ -0,0 +1,20 @@
+import 'package:lsp_server/lsp_server.dart' as lsp;
+import 'package:sass_api/sass_api.dart' as sass;
+
+import '../../utils/sass_lsp_utils.dart';
+import '../node_at_offset_visitor.dart';
+
+class SelectionRangesVisitor extends NodeAtOffsetVisitor {
+  final ranges = <lsp.SelectionRange>[];
+
+  SelectionRangesVisitor(super._offset);
+
+  @override
+  void processCandidate(sass.AstNode node) {
+    ranges.add(lsp.SelectionRange(range: toRange(node.span)));
+
+    if (node is sass.Declaration) {
+      ranges.add(lsp.SelectionRange(range: toRange(node.name.span)));
+    }
+  }
+}

pkgs/sass_language_services/lib/src/language_services.dart

@@ -5,6 +5,7 @@ import 'package:sass_language_services/src/features/document_highlights/document
 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';
 import 'package:sass_language_services/src/features/rename/rename_feature.dart';
+import 'package:sass_language_services/src/features/selection_ranges/selection_ranges_feature.dart';
 
 import 'features/document_links/document_links_feature.dart';
 import 'features/document_symbols/document_symbols_feature.dart';
@@ -25,6 +26,7 @@ class LanguageServices {
   late final GoToDefinitionFeature _goToDefinition;
   late final FindReferencesFeature _findReferences;
   late final RenameFeature _rename;
+  late final SelectionRangesFeature _selectionRanges;
   late final WorkspaceSymbolsFeature _workspaceSymbols;
 
   LanguageServices({
@@ -37,6 +39,7 @@ class LanguageServices {
     _goToDefinition = GoToDefinitionFeature(ls: this);
     _findReferences = FindReferencesFeature(ls: this);
     _rename = RenameFeature(ls: this);
+    _selectionRanges = SelectionRangesFeature(ls: this);
     _workspaceSymbols = WorkspaceSymbolsFeature(ls: this);
   }
 
@@ -67,6 +70,11 @@ class LanguageServices {
     return _workspaceSymbols.findWorkspaceSymbols(query);
   }
 
+  List<lsp.SelectionRange> getSelectionRanges(
+      TextDocument document, List<lsp.Position> positions) {
+    return _selectionRanges.getSelectionRanges(document, positions);
+  }
+
   Future<lsp.Location?> goToDefinition(
       TextDocument document, lsp.Position position) {
     return _goToDefinition.goToDefinition(document, position);

pkgs/sass_language_services/test/features/selection_ranges/selection_ranges_test.dart

@@ -0,0 +1,80 @@
+import 'package:lsp_server/lsp_server.dart' as lsp;
+import 'package:sass_language_services/sass_language_services.dart';
+import 'package:test/test.dart';
+
+import '../../memory_file_system.dart';
+import '../../position_utils.dart';
+import '../../test_client_capabilities.dart';
+
+final fs = MemoryFileSystem();
+final ls = LanguageServices(fs: fs, clientCapabilities: getCapabilities());
+
+void expectRanges(TextDocument document, lsp.SelectionRange ranges,
+    List<(int, String)> expected) {
+  var pairs = <(int, String)>[];
+  lsp.SelectionRange? current = ranges;
+  while (current != null) {
+    pairs.add((
+      document.offsetAt(current.range.start),
+      document.getText(range: current.range),
+    ));
+    current = current.parent;
+  }
+  expect(pairs, equals(expected));
+}
+
+void main() {
+  group('selection ranges', () {
+    setUp(() {
+      ls.cache.clear();
+    });
+
+    test('style rules', () {
+      var document = fs.createDocument('''.foo {
+  color: red;
+
+  .bar {
+    color: blue;
+  }
+}
+''');
+
+      var result = ls.getSelectionRanges(document, [position(4, 5)]);
+      expect(result, hasLength(1));
+      expectRanges(document, result.first, [
+        (0, ".foo {\n  color: red;\n\n  .bar {\n    color: blue;\n  }\n}\n"),
+        (0, ".foo {\n  color: red;\n\n  .bar {\n    color: blue;\n  }\n}"),
+        (24, ".bar {\n    color: blue;\n  }"),
+        (35, "color: blue"),
+        (35, "color")
+      ]);
+    });
+
+    test('mixin rules', () {
+      var document = fs.createDocument('''@mixin foo {
+  color: red;
+
+  .bar {
+    color: blue;
+  }
+}
+''');
+
+      var result = ls.getSelectionRanges(document, [position(4, 5)]);
+      expect(result, hasLength(1));
+      expectRanges(document, result.first, [
+        (
+          0,
+          "@mixin foo {\n  color: red;\n\n  .bar {\n    color: blue;\n  }\n}\n"
+        ),
+        (
+          0,
+          "@mixin foo {\n  color: red;\n\n  .bar {\n    color: blue;\n  }\n}"
+        ),
+        (30, ".bar {\n    color: blue;\n  }"),
+        (41, "color: blue"),
+        (41, "color")
+      ]);
+    });
+  });
+}