From 6d8a5f6288fe47e3e874d156017388829121876c Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Tue, 17 Jul 2018 13:35:55 -0700
Subject: [PATCH] Fix invalid cast: JSDocSignature is not a
 SignatureDeclaration (#25734)

---
 src/compiler/parser.ts                               |  6 +++---
 .../fourslash/updateSourceFile_jsdocSignature.ts     | 12 ++++++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100644 tests/cases/fourslash/updateSourceFile_jsdocSignature.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 1e4a793e566..942a56bcc30 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -494,9 +494,9 @@ namespace ts {
             case SyntaxKind.JSDocSignature:
                 return visitNodes(cbNode, cbNodes, node.decorators) ||
                     visitNodes(cbNode, cbNodes, node.modifiers) ||
-                    visitNodes(cbNode, cbNodes, (<SignatureDeclaration>node).typeParameters) ||
-                    visitNodes(cbNode, cbNodes, (<SignatureDeclaration>node).parameters) ||
-                    visitNode(cbNode, (<SignatureDeclaration>node).type);
+                    forEach((<JSDocSignature>node).typeParameters, cbNode) ||
+                    forEach((<JSDocSignature>node).parameters, cbNode) ||
+                    visitNode(cbNode, (<JSDocSignature>node).type);
             case SyntaxKind.JSDocTypeLiteral:
                 if ((node as JSDocTypeLiteral).jsDocPropertyTags) {
                     for (const tag of (node as JSDocTypeLiteral).jsDocPropertyTags!) {
diff --git a/tests/cases/fourslash/updateSourceFile_jsdocSignature.ts b/tests/cases/fourslash/updateSourceFile_jsdocSignature.ts
new file mode 100644
index 00000000000..13261acde0d
--- /dev/null
+++ b/tests/cases/fourslash/updateSourceFile_jsdocSignature.ts
@@ -0,0 +1,12 @@
+/// <reference path='fourslash.ts' />
+
+/////**
+//// * @callback Cb
+//// * @return {/**/}
+//// */
+////let x;
+
+// Previously this crashed due to an invalid cast in `forEachChild` for `JSDocSignature`.
+
+goTo.marker("");
+edit.insert("number");