Add es6-set polyfill for test_utils.js

app/assets/javascripts/test_utils/index.js

 import 'es6-map/implement';
+import 'es6-set/implement';
 import simulateDrag from './simulate_drag';
 
 // Export to global space for rspec to use

package.json

@@ -29,6 +29,7 @@
     "dropzone": "^4.2.0",
     "emoji-unicode-version": "^0.2.1",
     "es6-map": "^0.1.5",
+    "es6-set": "^0.1.5",
     "eslint-plugin-html": "^2.0.1",
     "exports-loader": "^0.6.4",
     "file-loader": "^0.11.1",

yarn.lock

@@ -1540,7 +1540,7 @@ d@1:
   dependencies:
     es5-ext "^0.10.9"
 
-d@^0.1.1, d@~0.1.1:
+d@^0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/d/-/d-0.1.1.tgz#da184c535d18d8ee7ba2aa229b914009fae11309"
   dependencies:
@@ -1872,29 +1872,14 @@ error-ex@^1.2.0:
   dependencies:
     is-arrayish "^0.2.1"
 
-es5-ext@^0.10.14, es5-ext@^0.10.9, es5-ext@~0.10.14:
+es5-ext@^0.10.14, es5-ext@^0.10.8, es5-ext@^0.10.9, es5-ext@~0.10.14, es5-ext@~0.10.2:
   version "0.10.24"
   resolved "https://registry.yarnpkg.com/es5-ext/-/es5-ext-0.10.24.tgz#a55877c9924bc0c8d9bd3c2cbe17495ac1709b14"
   dependencies:
     es6-iterator "2"
     es6-symbol "~3.1"
 
-es5-ext@^0.10.7, es5-ext@^0.10.8, es5-ext@~0.10.11, es5-ext@~0.10.2, es5-ext@~0.10.7:
-  version "0.10.12"
-  resolved "https://registry.yarnpkg.com/es5-ext/-/es5-ext-0.10.12.tgz#aa84641d4db76b62abba5e45fd805ecbab140047"
-  dependencies:
-    es6-iterator "2"
-    es6-symbol "~3.1"
-
-es6-iterator@2:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/es6-iterator/-/es6-iterator-2.0.0.tgz#bd968567d61635e33c0b80727613c9cb4b096bac"
-  dependencies:
-    d "^0.1.1"
-    es5-ext "^0.10.7"
-    es6-symbol "3"
-
-es6-iterator@~2.0.1:
+es6-iterator@2, es6-iterator@~2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/es6-iterator/-/es6-iterator-2.0.1.tgz#8e319c9f0453bf575d374940a655920e59ca5512"
   dependencies:
@@ -1902,18 +1887,7 @@ es6-iterator@~2.0.1:
     es5-ext "^0.10.14"
     es6-symbol "^3.1"
 
-es6-map@^0.1.3:
-  version "0.1.4"
-  resolved "https://registry.yarnpkg.com/es6-map/-/es6-map-0.1.4.tgz#a34b147be224773a4d7da8072794cefa3632b897"
-  dependencies:
-    d "~0.1.1"
-    es5-ext "~0.10.11"
-    es6-iterator "2"
-    es6-set "~0.1.3"
-    es6-symbol "~3.1.0"
-    event-emitter "~0.3.4"
-
-es6-map@^0.1.5:
+es6-map@^0.1.3, es6-map@^0.1.5:
   version "0.1.5"
   resolved "https://registry.yarnpkg.com/es6-map/-/es6-map-0.1.5.tgz#9136e0503dcc06a301690f0bb14ff4e364e949f0"
   dependencies:
@@ -1928,17 +1902,7 @@ es6-promise@^3.0.2, es6-promise@~3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-3.0.2.tgz#010d5858423a5f118979665f46486a95c6ee2bb6"
 
-es6-set@~0.1.3:
-  version "0.1.4"
-  resolved "https://registry.yarnpkg.com/es6-set/-/es6-set-0.1.4.tgz#9516b6761c2964b92ff479456233a247dc707ce8"
-  dependencies:
-    d "~0.1.1"
-    es5-ext "~0.10.11"
-    es6-iterator "2"
-    es6-symbol "3"
-    event-emitter "~0.3.4"
-
-es6-set@~0.1.5:
+es6-set@^0.1.5, es6-set@~0.1.5:
   version "0.1.5"
   resolved "https://registry.yarnpkg.com/es6-set/-/es6-set-0.1.5.tgz#d2b3ec5d4d800ced818db538d28974db0a73ccb1"
   dependencies:
@@ -1948,14 +1912,7 @@ es6-set@~0.1.5:
     es6-symbol "3.1.1"
     event-emitter "~0.3.5"
 
-es6-symbol@3, es6-symbol@~3.1, es6-symbol@~3.1.0:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/es6-symbol/-/es6-symbol-3.1.0.tgz#94481c655e7a7cad82eba832d97d5433496d7ffa"
-  dependencies:
-    d "~0.1.1"
-    es5-ext "~0.10.11"
-
-es6-symbol@3.1.1, es6-symbol@^3.1, es6-symbol@~3.1.1:
+es6-symbol@3, es6-symbol@3.1.1, es6-symbol@^3.1, es6-symbol@~3.1, es6-symbol@~3.1.1:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/es6-symbol/-/es6-symbol-3.1.1.tgz#bf00ef4fdab6ba1b46ecb7b629b4c7ed5715cc77"
   dependencies:
@@ -2156,13 +2113,6 @@ eve-raphael@0.5.0:
   version "0.5.0"
   resolved "https://registry.yarnpkg.com/eve-raphael/-/eve-raphael-0.5.0.tgz#17c754b792beef3fa6684d79cf5a47c63c4cda30"
 
-event-emitter@~0.3.4:
-  version "0.3.4"
-  resolved "https://registry.yarnpkg.com/event-emitter/-/event-emitter-0.3.4.tgz#8d63ddfb4cfe1fae3b32ca265c4c720222080bb5"
-  dependencies:
-    d "~0.1.1"
-    es5-ext "~0.10.7"
-
 event-emitter@~0.3.5:
   version "0.3.5"
   resolved "https://registry.yarnpkg.com/event-emitter/-/event-emitter-0.3.5.tgz#df8c69eef1647923c7157b9ce83840610b02cc39"