From 07a371bbf665d29f6b349bd142efcef862fe7fa8 Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrew@wheream.io>
Date: Fri, 25 Oct 2019 16:13:47 -0700
Subject: [PATCH] Fix extract type on JS function params

---
 src/services/refactors/extractType.ts          |  6 +-----
 .../cases/fourslash/refactorExtractType_js7.ts | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)
 create mode 100644 tests/cases/fourslash/refactorExtractType_js7.ts

diff --git a/src/services/refactors/extractType.ts b/src/services/refactors/extractType.ts
index ba06814c4ea..70934ef7a7c 100644
--- a/src/services/refactors/extractType.ts
+++ b/src/services/refactors/extractType.ts
@@ -68,7 +68,7 @@ namespace ts.refactor {
         if (!selection || !isTypeNode(selection)) return undefined;
 
         const checker = context.program.getTypeChecker();
-        const firstStatement = Debug.assertDefined(isJS ? findAncestor(selection, isStatementAndHasJSDoc) : findAncestor(selection, isStatement), "Should find a statement");
+        const firstStatement = Debug.assertDefined(findAncestor(selection, isStatement), "Should find a statement");
         const typeParameters = collectTypeParameters(checker, selection, firstStatement, file);
         if (!typeParameters) return undefined;
 
@@ -100,10 +100,6 @@ namespace ts.refactor {
         return undefined;
     }
 
-    function isStatementAndHasJSDoc(n: Node): n is (Statement & HasJSDoc) {
-        return isStatement(n) && hasJSDocNodes(n);
-    }
-
     function rangeContainsSkipTrivia(r1: TextRange, node: Node, file: SourceFile): boolean {
         return rangeContainsStartEnd(r1, skipTrivia(file.text, node.pos), node.end);
     }
diff --git a/tests/cases/fourslash/refactorExtractType_js7.ts b/tests/cases/fourslash/refactorExtractType_js7.ts
new file mode 100644
index 00000000000..c3543ef36e2
--- /dev/null
+++ b/tests/cases/fourslash/refactorExtractType_js7.ts
@@ -0,0 +1,18 @@
+/// <reference path='fourslash.ts' />
+
+// @allowJs: true
+// @Filename: a.js
+////function a(/** @type {/*a*/string/*b*/} */ b) {}
+
+goTo.file('a.js')
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Extract type",
+    actionName: "Extract to typedef",
+    actionDescription: "Extract to typedef",
+    newContent: `/**
+ * @typedef {string} /*RENAME*/NewType
+ */
+
+function a(/** @type {NewType} */ b) {}`,
+});