From 8012c988738e2e598696ad87dc738a41dfdaa5b3 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Mon, 25 Jun 2018 10:50:37 -0700
Subject: [PATCH 1/2] Simplify addJSDocComment

---
 src/compiler/parser.ts | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index ea0ec323798bc..5025be23ad93d 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -864,13 +864,8 @@ namespace ts {
         }
 
         function addJSDocComment<T extends HasJSDoc>(node: T): T {
-            const comments = getJSDocCommentRanges(node, sourceFile.text);
-            if (comments) {
-                for (const comment of comments) {
-                    node.jsDoc = append<JSDoc>(node.jsDoc, JSDocParser.parseJSDocComment(node, comment.pos, comment.end - comment.pos));
-                }
-            }
-
+            const jsDoc = mapDefined(getJSDocCommentRanges(node, sourceFile.text), comment => JSDocParser.parseJSDocComment(node, comment.pos, comment.end - comment.pos));
+            if (jsDoc.length) node.jsDoc = jsDoc;
             return node;
         }
 

From a51bbb5c500d838332e0cdb48394d9b7dea21fac Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Mon, 25 Jun 2018 10:58:53 -0700
Subject: [PATCH 2/2] Add assert

---
 src/compiler/parser.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 5025be23ad93d..015c7d69f443b 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -864,6 +864,7 @@ namespace ts {
         }
 
         function addJSDocComment<T extends HasJSDoc>(node: T): T {
+            Debug.assert(!node.jsDoc); // Should only be called once per node
             const jsDoc = mapDefined(getJSDocCommentRanges(node, sourceFile.text), comment => JSDocParser.parseJSDocComment(node, comment.pos, comment.end - comment.pos));
             if (jsDoc.length) node.jsDoc = jsDoc;
             return node;