From 3d95e8317b04bcf2859a40cd63ce1a1d72c109a3 Mon Sep 17 00:00:00 2001
From: Christopher Chedeau <vjeuxx@gmail.com>
Date: Sun, 22 Jan 2017 12:34:35 -0800
Subject: [PATCH] Fix forced trailing comma (#382)

We shouldn't output trailing commas when there is a forced one when we break.

Fixes #380
---
 src/printer.js                              | 2 +-
 tests/rest/__snapshots__/jsfmt.spec.js.snap | 7 +++++++
 tests/rest/trailing-commas.js               | 2 ++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/printer.js b/src/printer.js
index 6cc228b22..753e1436d 100644
--- a/src/printer.js
+++ b/src/printer.js
@@ -637,7 +637,7 @@ function genericPrintNoParens(path, options, print) {
                 ])
               ),
               needsForcedTrailingComma ? "," : "",
-              ifBreak(options.trailingComma ? "," : ""),
+              ifBreak(!needsForcedTrailingComma && options.trailingComma ? "," : ""),
               options.bracketSpacing ? line : softline,
               "]"
             ])
diff --git a/tests/rest/__snapshots__/jsfmt.spec.js.snap b/tests/rest/__snapshots__/jsfmt.spec.js.snap
index 79cff5aa0..aaf012afd 100644
--- a/tests/rest/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/rest/__snapshots__/jsfmt.spec.js.snap
@@ -12,6 +12,8 @@ function f(
 ) {}
 
 declare class C { f(...superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong): void; }
+
+[superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong,,]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 declare class C {
   f(
@@ -31,5 +33,10 @@ declare class C {
     ...superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong
   ): void,
 }
+
+[
+  superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong,
+  ,
+];
 "
 `;
diff --git a/tests/rest/trailing-commas.js b/tests/rest/trailing-commas.js
index 65a05498a..8fabb7268 100644
--- a/tests/rest/trailing-commas.js
+++ b/tests/rest/trailing-commas.js
@@ -11,3 +11,5 @@ function f(
 ) {}
 
 declare class C { f(...superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong): void; }
+
+[superSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperSuperLong,,]