Don’t include local variables in document symbols

Fixes #962
rdar://117810784

Author: ahoppen

Sources/SourceKitLSP/Swift/DocumentSymbols.swift

@@ -180,7 +180,9 @@ fileprivate final class DocumentSymbolsFinder: SyntaxAnyVisitor {
     // If there is only one pattern binding within the variable decl, consider the entire variable decl as the
     // referenced range. If there are multiple, consider each pattern binding separately since the `var` keyword doesn't
     // belong to any pattern binding in particular.
-    guard let variableDecl = node.parent?.parent?.as(VariableDeclSyntax.self) else {
+    guard let variableDecl = node.parent?.parent?.as(VariableDeclSyntax.self),
+      variableDecl.isMemberOrTopLevelDeclaration
+    else {
       return .visitChildren
     }
     let rangeNode: Syntax = variableDecl.bindings.count == 1 ? Syntax(variableDecl) : Syntax(node)
@@ -228,6 +230,19 @@ fileprivate extension SyntaxProtocol {
   var rangeWithoutTrivia: Range<AbsolutePosition> {
     return positionAfterSkippingLeadingTrivia..<endPositionBeforeTrailingTrivia
   }
+
+  /// Whether this is a top-level constant or a member of a type, ie. if this is not a local variable.
+  var isMemberOrTopLevelDeclaration: Bool {
+    if self.parent?.is(MemberBlockItemSyntax.self) ?? false {
+      return true
+    } else if let codeBlockItem = self.parent?.as(CodeBlockItemSyntax.self),
+      codeBlockItem.parent?.parent?.is(SourceFileSyntax.self) ?? false
+    {
+      return true
+    } else {
+      return false
+    }
+  }
 }
 
 fileprivate extension TokenKind {

Tests/SourceKitLSPTests/DocumentSymbolTests.swift

@@ -571,8 +571,8 @@ final class DocumentSymbolTests: XCTestCase {
     try await assertDocumentSymbols(
       """
       1️⃣func 2️⃣f()3️⃣ {
-        4️⃣let 5️⃣localConstant6️⃣ = 07️⃣
-      }8️⃣
+        let localConstant = 0
+      }4️⃣
       """
     ) { positions in
       [
@@ -581,19 +581,9 @@ final class DocumentSymbolTests: XCTestCase {
           detail: nil,
           kind: .function,
           deprecated: nil,
-          range: positions["1️⃣"]..<positions["8️⃣"],
+          range: positions["1️⃣"]..<positions["4️⃣"],
           selectionRange: positions["2️⃣"]..<positions["3️⃣"],
-          children: [
-            DocumentSymbol(
-              name: "localConstant",
-              detail: nil,
-              kind: .variable,
-              deprecated: nil,
-              range: positions["4️⃣"]..<positions["7️⃣"],
-              selectionRange: positions["5️⃣"]..<positions["6️⃣"],
-              children: []
-            )
-          ]
+          children: []
         )
       ]
     }