From 192a99f51df744c1088994ca114ef46294487e89 Mon Sep 17 00:00:00 2001
From: Mark Pedrotti <pedrottimark@gmail.com>
Date: Mon, 7 Aug 2017 14:52:14 -0400
Subject: [PATCH] Replace concat(Immutable) with Immutable as item of plugins
 array (#4207)

---
 packages/jest-diff/src/index.js                        | 3 ++-
 packages/jest-matcher-utils/src/index.js               | 3 ++-
 packages/jest-snapshot/src/plugins.js                  | 2 +-
 packages/pretty-format/src/__tests__/immutable.test.js | 9 +++++----
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/packages/jest-diff/src/index.js b/packages/jest-diff/src/index.js
index d7976a25a909..129dbb2d5787 100644
--- a/packages/jest-diff/src/index.js
+++ b/packages/jest-diff/src/index.js
@@ -28,8 +28,9 @@ const PLUGINS = [
   ReactTestComponent,
   ReactElement,
   HTMLElement,
+  Immutable,
   AsymmetricMatcher,
-].concat(Immutable);
+];
 const FORMAT_OPTIONS = {
   plugins: PLUGINS,
 };
diff --git a/packages/jest-matcher-utils/src/index.js b/packages/jest-matcher-utils/src/index.js
index effc9421b0a0..0ed181e2566b 100644
--- a/packages/jest-matcher-utils/src/index.js
+++ b/packages/jest-matcher-utils/src/index.js
@@ -23,8 +23,9 @@ const PLUGINS = [
   ReactTestComponent,
   ReactElement,
   HTMLElement,
+  Immutable,
   AsymmetricMatcher,
-].concat(Immutable);
+];
 
 const EXPECTED_COLOR = chalk.green;
 const EXPECTED_BG = chalk.bgGreen;
diff --git a/packages/jest-snapshot/src/plugins.js b/packages/jest-snapshot/src/plugins.js
index 58bf77c5624d..4fe82dafefc0 100644
--- a/packages/jest-snapshot/src/plugins.js
+++ b/packages/jest-snapshot/src/plugins.js
@@ -19,7 +19,7 @@ const {
   ReactTestComponent,
 } = prettyFormat.plugins;
 
-let PLUGINS = [ReactTestComponent, ReactElement, HTMLElement].concat(Immutable);
+let PLUGINS = [ReactTestComponent, ReactElement, HTMLElement, Immutable];
 
 // Prepend to list so the last added is the first tested.
 exports.addSerializer = (plugin: Plugin) => {
diff --git a/packages/pretty-format/src/__tests__/immutable.test.js b/packages/pretty-format/src/__tests__/immutable.test.js
index f0e45b913f3f..059f4e52a5e6 100644
--- a/packages/pretty-format/src/__tests__/immutable.test.js
+++ b/packages/pretty-format/src/__tests__/immutable.test.js
@@ -13,12 +13,13 @@
 import React from 'react';
 import Immutable from 'immutable';
 import prettyFormat from '../';
-const {Immutable: ImmutablePlugins, ReactElement} = prettyFormat.plugins;
+const {Immutable: ImmutablePlugin, ReactElement} = prettyFormat.plugins;
 import expectUtil from './expect_util';
 
-const toPrettyPrintTo = expectUtil.getPrettyPrint(
-  [ReactElement].concat(ImmutablePlugins),
-);
+const toPrettyPrintTo = expectUtil.getPrettyPrint([
+  ReactElement,
+  ImmutablePlugin,
+]);
 
 const expect = global.expect;
 expect.extend({toPrettyPrintTo});