Fix getTokensFromNode template scanning issue

internal/ls/signaturehelp.go

@@ -1083,6 +1083,12 @@ func getTokensFromNode(node *ast.Node, sourceFile *ast.SourceFile) []*ast.Node {
 	if node == nil {
 		return nil
 	}
+
+	// Special handling for template expressions
+	if node.Kind == ast.KindTemplateExpression {
+		return getTokensFromTemplateExpression(node, sourceFile)
+	}
+
 	var children []*ast.Node
 	current := node
 	left := node.Pos()
@@ -1098,6 +1104,31 @@ func getTokensFromNode(node *ast.Node, sourceFile *ast.SourceFile) []*ast.Node {
 	return children
 }
 
+func getTokensFromTemplateExpression(node *ast.Node, sourceFile *ast.SourceFile) []*ast.Node {
+	templateExpr := node.AsTemplateExpression()
+	var children []*ast.Node
+
+	// Add the template head
+	head := templateExpr.Head
+	children = append(children, head.AsNode())
+
+	// Add tokens for each template span
+	if templateExpr.TemplateSpans != nil {
+		for _, spanNode := range templateExpr.TemplateSpans.Nodes {
+			span := spanNode.AsTemplateSpan()
+
+			// Add tokens from the expression part
+			exprTokens := getTokensFromNode(span.Expression.AsNode(), sourceFile)
+			children = append(children, exprTokens...)
+
+			// Add the template literal part (middle or tail)
+			children = append(children, span.Literal.AsNode())
+		}
+	}
+
+	return children
+}
+
 func getTokenFromNodeList(nodeList *ast.NodeList, nodeListParent *ast.Node, sourceFile *ast.SourceFile) []*ast.Node {
 	if nodeList == nil || nodeListParent == nil {
 		return nil

internal/ls/signaturehelp_test.go

@@ -580,6 +580,15 @@ f("x", /**/);`,
 				"": {text: `f(a: "x", b: "x", c: "x"): void`, parameterCount: 3, parameterSpan: `b: "x"`, activeParameter: &lsproto.UintegerOrNull{Uinteger: ptrTo(uint32(1))}},
 			},
 		},
+		{
+			title: "signatureHelpTaggedTemplate",
+			input: `function tag(strings: TemplateStringsArray, ...values: any[]) { return ""; }
+const value = 42;
+const result = tag` + "`Hello ${value} /*1*/ world ${value}!`" + `;`,
+			expected: map[string]verifySignatureHelpOptions{
+				"1": {text: "tag(strings: TemplateStringsArray, ...values: any[]): string", parameterCount: 2, parameterSpan: "...values: any[]", activeParameter: &lsproto.UintegerOrNull{Uinteger: ptrTo(uint32(1))}},
+			},
+		},
 		{
 			title: "signatureHelpInParenthetical",
 			input: `class base { constructor (public n: number, public y: string) { } }