Add pretty-inmutable for better error message [issue-2489]

packages/jest-matcher-utils/src/index.js

@@ -12,6 +12,7 @@
 
 const chalk = require('chalk');
 const prettyFormat = require('pretty-format');
+const ImmutablePlugin = require('pretty-format/build/plugins/Inmutable');
 
 export type ValueType =
   | 'array'
@@ -89,6 +90,7 @@ const stringify = (object: any, maxDepth?: number = 10): string => {
     result = prettyFormat(object, {
       maxDepth,
       min: true,
+      plugins: [ImmutablePlugin],
     });
   } catch (e) {
     result = prettyFormat(object, {

packages/pretty-format/package.json

@@ -14,6 +14,8 @@
     "perf": "node perf/test.js"
   },
   "dependencies": {
-    "ansi-styles": "^2.2.1"
+    "ansi-styles": "^2.2.1",
+    "immutable": "^3.8.1",
+    "pretty-immutable": "^1.0.1"
   }
 }

packages/pretty-format/src/plugins/Inmutable.js

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+/* eslint-disable max-len */
+'use strict';
+const prettyI = require('pretty-immutable');
+const InmutableTypes = ['List', 'OrderedSet'];
+const isInMutable = val => {
+  return (element, index, array) => val.toString().includes(element);
+};
+
+module.exports = {
+  print(val, print, indent) {
+    return 'Inmutable ' + prettyI(val);
+  },
+  test(val) {
+    return val && InmutableTypes.some(isInMutable(val));
+  },
+};

packages/pretty-format/yarn.lock

@@ -0,0 +1,26 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+ansi-styles@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
+
+immutable@^3.8.1:
+  version "3.8.1"
+  resolved "https://registry.yarnpkg.com/immutable/-/immutable-3.8.1.tgz#200807f11ab0f72710ea485542de088075f68cd2"
+
+json-stringify-pretty-compact@^1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/json-stringify-pretty-compact/-/json-stringify-pretty-compact-1.0.2.tgz#abe8ae193feb19020dfeec74363be03d65821a31"
+
+pretty-immutable@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/pretty-immutable/-/pretty-immutable-1.0.1.tgz#0a41d508fea2a6099c330f5d998e65722b3580a0"
+  dependencies:
+    json-stringify-pretty-compact "^1.0.1"
+    repeat-string "^1.5.4"
+
+repeat-string@^1.5.4:
+  version "1.6.1"
+  resolved "https://registry.yarnpkg.com/repeat-string/-/repeat-string-1.6.1.tgz#8dcae470e1c88abc2d600fff4a776286da75e637"