vendor tsgo

tools/tsgo/internal/ast/deepclone.go

@@ -0,0 +1,86 @@
+package ast
+
+import "github.com/microsoft/typescript-go/internal/core"
+
+// Ideally, this would get cached on the node factory so there's only ever one set of closures made per factory
+func getDeepCloneVisitor(f *NodeFactory, syntheticLocation bool) *NodeVisitor {
+	var visitor *NodeVisitor
+	visitor = NewNodeVisitor(
+		func(node *Node) *Node {
+			visited := visitor.VisitEachChild(node)
+			if visited != node {
+				if syntheticLocation {
+					visited.Loc = core.NewTextRange(-1, -1)
+				}
+				return visited
+			}
+			c := node.Clone(f) // forcibly clone leaf nodes, which will then cascade new nodes/arrays upwards via `update` calls
+			// In strada, `factory.cloneNode` was dynamic and did _not_ clone positions for any "special cases", meanwhile
+			// Node.Clone in corsa reliably uses `Update` calls for all nodes and so copies locations by default.
+			// Deep clones are done to copy a node across files, so here, we explicitly make the location range synthetic on all cloned nodes
+			if syntheticLocation {
+				c.Loc = core.NewTextRange(-1, -1)
+			}
+			return c
+		},
+		f,
+		NodeVisitorHooks{
+			VisitNodes: func(nodes *NodeList, v *NodeVisitor) *NodeList {
+				if nodes == nil {
+					return nil
+				}
+				visited := v.VisitNodes(nodes)
+				var newList *NodeList
+				if visited != nodes {
+					newList = visited
+				} else {
+					newList = nodes.Clone(v.Factory)
+				}
+				if syntheticLocation {
+					newList.Loc = core.NewTextRange(-1, -1)
+					if nodes.HasTrailingComma() {
+						newList.Nodes[len(newList.Nodes)-1].Loc = core.NewTextRange(-2, -2)
+					}
+				}
+				return newList
+			},
+			VisitModifiers: func(nodes *ModifierList, v *NodeVisitor) *ModifierList {
+				if nodes == nil {
+					return nil
+				}
+				visited := v.VisitModifiers(nodes)
+				var newList *ModifierList
+				if visited != nodes {
+					newList = visited
+				} else {
+					newList = nodes.Clone(v.Factory)
+				}
+				if syntheticLocation {
+					newList.Loc = core.NewTextRange(-1, -1)
+					if nodes.HasTrailingComma() {
+						newList.Nodes[len(newList.Nodes)-1].Loc = core.NewTextRange(-2, -2)
+					}
+				}
+				return newList
+			},
+		},
+	)
+	return visitor
+}
+
+func (f *NodeFactory) DeepCloneNode(node *Node) *Node {
+	return getDeepCloneVisitor(f, true /*syntheticLocation*/).VisitNode(node)
+}
+
+func (f *NodeFactory) DeepCloneReparse(node *Node) *Node {
+	if node != nil {
+		node = getDeepCloneVisitor(f, false /*syntheticLocation*/).VisitNode(node)
+		SetParentInChildren(node)
+		node.Flags |= NodeFlagsReparsed
+	}
+	return node
+}
+
+func (f *NodeFactory) DeepCloneReparseModifiers(modifiers *ModifierList) *ModifierList {
+	return getDeepCloneVisitor(f, false /*syntheticLocation*/).VisitModifiers(modifiers)
+}