From e3bfec5217bf8375e9b16ad117977308d27d240c Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Fri, 12 Oct 2018 15:58:31 -0700
Subject: [PATCH 1/2] Handle when advancing past , of call expression moves
 past endPos of formatting Fixes #26513

---
 src/services/formatting/formatting.ts                      | 6 +++---
 tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts | 7 +++++++
 2 files changed, 10 insertions(+), 3 deletions(-)
 create mode 100644 tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts

diff --git a/src/services/formatting/formatting.ts b/src/services/formatting/formatting.ts
index c1de1574e88..0ed6e84e2c3 100644
--- a/src/services/formatting/formatting.ts
+++ b/src/services/formatting/formatting.ts
@@ -753,17 +753,17 @@ namespace ts.formatting {
 
                 const listEndToken = getCloseTokenForOpenToken(listStartToken);
                 if (listEndToken !== SyntaxKind.Unknown && formattingScanner.isOnToken()) {
-                    let tokenInfo = formattingScanner.readTokenInfo(parent);
+                    let tokenInfo: TokenInfo | undefined = formattingScanner.readTokenInfo(parent);
                     if (tokenInfo.token.kind === SyntaxKind.CommaToken && isCallLikeExpression(parent)) {
                         formattingScanner.advance();
-                        tokenInfo = formattingScanner.readTokenInfo(parent);
+                        tokenInfo = formattingScanner.isOnToken() ? formattingScanner.readTokenInfo(parent) : undefined;
                     }
 
                     // consume the list end token only if it is still belong to the parent
                     // there might be the case when current token matches end token but does not considered as one
                     // function (x: function) <--
                     // without this check close paren will be interpreted as list end token for function expression which is wrong
-                    if (tokenInfo.token.kind === listEndToken && rangeContainsRange(parent, tokenInfo.token)) {
+                    if (tokenInfo && tokenInfo.token.kind === listEndToken && rangeContainsRange(parent, tokenInfo.token)) {
                         // consume list end token
                         consumeTokenAndAdvanceScanner(tokenInfo, parent, listDynamicIndentation, parent);
                     }
diff --git a/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts b/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts
new file mode 100644
index 00000000000..30f4d3faf75
--- /dev/null
+++ b/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts
@@ -0,0 +1,7 @@
+/// <reference path="fourslash.ts"/>
+////export const strong: StrongParser = verify(fmap(build(() =>
+////    /*start*/surround('**', compress(some(union([inline]), '**')), '**')),/*end*/
+////    ns => [html('strong', ns)]
+////), ([el]) => hasTightStartText(el));
+
+format.selection("start", "end");
\ No newline at end of file

From 3aa33aa4ed9067dbc1addc8a64e6e42da2ed5d61 Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Mon, 15 Oct 2018 15:55:45 -0700
Subject: [PATCH 2/2] Simplify the test

---
 .../cases/fourslash/formatRangeEndingAfterCommaOfCall.ts  | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts b/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts
index 30f4d3faf75..824839ff4af 100644
--- a/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts
+++ b/tests/cases/fourslash/formatRangeEndingAfterCommaOfCall.ts
@@ -1,7 +1,7 @@
 /// <reference path="fourslash.ts"/>
-////export const strong: StrongParser = verify(fmap(build(() =>
-////    /*start*/surround('**', compress(some(union([inline]), '**')), '**')),/*end*/
-////    ns => [html('strong', ns)]
-////), ([el]) => hasTightStartText(el));
+////someCall(
+////    /*start*/"firstParameter",/*end*/
+////    "something else"
+////);
 
 format.selection("start", "end");
\ No newline at end of file