Folding Ranges implementation

internal/ast/utilities.go

@@ -663,6 +663,49 @@ func isDeclarationStatementKind(kind Kind) bool {
 	return false
 }
 
+func isDeclarationKind(kind Kind) bool {
+	switch kind {
+	case KindArrowFunction,
+		KindBindingElement,
+		KindClassDeclaration,
+		KindClassExpression,
+		KindClassStaticBlockDeclaration,
+		KindConstructor,
+		KindEnumDeclaration,
+		KindEnumMember,
+		KindExportSpecifier,
+		KindFunctionDeclaration,
+		KindFunctionExpression,
+		KindGetAccessor,
+		KindImportClause,
+		KindImportEqualsDeclaration,
+		KindImportSpecifier,
+		KindInterfaceDeclaration,
+		KindJsxAttribute,
+		KindMethodDeclaration,
+		KindMethodSignature,
+		KindModuleDeclaration,
+		KindNamespaceExportDeclaration,
+		KindNamespaceExport,
+		KindNamespaceImport,
+		KindParameter,
+		KindPropertyAssignment,
+		KindPropertyDeclaration,
+		KindPropertySignature,
+		KindSetAccessor,
+		KindShorthandPropertyAssignment,
+		KindTypeAliasDeclaration,
+		KindTypeParameter,
+		KindVariableDeclaration,
+		KindJSDocTypedefTag,
+		KindJSDocCallbackTag,
+		KindJSDocPropertyTag,
+		KindNamedTupleMember:
+		return true
+	}
+	return false
+}
+
 // Determines whether a node is a DeclarationStatement. Ideally this does not use Parent pointers, but it may use them
 // to rule out a Block node that is part of `try` or `catch` or is the Block-like body of a function.
 //
@@ -1265,7 +1308,7 @@ func IsDeclaration(node *Node) bool {
 	if node.Kind == KindTypeParameter {
 		return node.Parent != nil
 	}
-	return IsDeclarationNode(node)
+	return isDeclarationKind(node.Kind)
 }
 
 // True if `name` is the name of a declaration node