🎄🔨 Force tree shake emojione (#4202)

* chore(yarn): Install babel-plugin-preval as development dependency

* feat(babel): Add preval as a plugin

* feat(emojione_light): Prevaled module what tree-shaked emojione

* refactor(emoji): Use emojione_light

* feat: Preload emojione_picker bundle

* fix(emojione_light): Do not use Object.entries

* fix(emojify): Update tests

* chore(emojione_light): Remove silly ascii art

7 files changed, 39 insertions, 20 deletions

diff --git a/.babelrc b/.babelrc
index 19968964e..de922f389 100644
--- a/.babelrc
+++ b/.babelrc
@@ -22,7 +22,8 @@
       {
         "messagesDir": "./build/messages"
       }
-    ]
+    ],
+    "preval"
   ],
   "env": {
     "development": {
diff --git a/app/javascript/mastodon/emoji.js b/app/javascript/mastodon/emoji.js
index ed2180cd1..1de41f572 100644
--- a/app/javascript/mastodon/emoji.js
+++ b/app/javascript/mastodon/emoji.js
@@ -1,8 +1,7 @@
-import emojione from 'emojione';
+import { unicodeToFilename } from './emojione_light';
 import Trie from 'substring-trie';
 
-const mappedUnicode = emojione.mapUnicodeToShort();
-const trie = new Trie(Object.keys(emojione.jsEscapeMap));
+const trie = new Trie(Object.keys(unicodeToFilename));
 
 function emojify(str) {
   // This walks through the string from start to end, ignoring any tags (<p>, <br>, etc.)
@@ -20,12 +19,10 @@ function emojify(str) {
       insideTag = true;
     } else if (!insideTag && (match = trie.search(str.substring(i)))) {
       const unicodeStr = match;
-      if (unicodeStr in emojione.jsEscapeMap) {
-        const unicode  = emojione.jsEscapeMap[unicodeStr];
-        const short    = mappedUnicode[unicode];
-        const filename = emojione.emojioneList[short].fname;
-        const alt      = emojione.convert(unicode.toUpperCase());
-        const replacement =  `<img draggable="false" class="emojione" alt="${alt}" title="${short}" src="/emoji/${filename}.svg" />`;
+      if (unicodeStr in unicodeToFilename) {
+        const filename = unicodeToFilename[unicodeStr];
+        const alt      = unicodeStr;
+        const replacement =  `<img draggable="false" class="emojione" alt="${alt}" src="/emoji/${filename}.svg" />`;
         str = str.substring(0, i) + replacement + str.substring(i + unicodeStr.length);
         i += (replacement.length - unicodeStr.length); // jump ahead the length we've added to the string
       }
diff --git a/app/javascript/mastodon/emojione_light.js b/app/javascript/mastodon/emojione_light.js
new file mode 100644
index 000000000..c75e10a98
--- /dev/null
+++ b/app/javascript/mastodon/emojione_light.js
@@ -0,0 +1,11 @@
+// @preval
+// Force tree shaking on emojione by exposing just a subset of its functionality
+
+const emojione = require('emojione');
+
+const mappedUnicode = emojione.mapUnicodeToShort();
+
+module.exports.unicodeToFilename = Object.keys(emojione.jsEscapeMap)
+  .map(unicodeStr => [unicodeStr, mappedUnicode[emojione.jsEscapeMap[unicodeStr]]])
+  .map(([unicodeStr, shortCode]) => ({ [unicodeStr]: emojione.emojioneList[shortCode].fname }))
+  .reduce((x, y) => Object.assign(x, y), { });
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index ef97fb127..82b20810a 100755
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -27,6 +27,7 @@
     = javascript_pack_tag 'features/notifications', integrity: true, crossorigin: 'anonymous', rel: 'preload', as: 'script'
     = javascript_pack_tag 'features/community_timeline', integrity: true, crossorigin: 'anonymous', rel: 'preload', as: 'script'
     = javascript_pack_tag 'features/public_timeline', integrity: true, crossorigin: 'anonymous', rel: 'preload', as: 'script'
+    = javascript_pack_tag 'emojione_picker', integrity: true, crossorigin: 'anonymous', rel: 'preload', as: 'script'
 
     = javascript_pack_tag "locale_#{I18n.locale}", integrity: true, crossorigin: 'anonymous'
     = csrf_meta_tags
diff --git a/package.json b/package.json
index 5ad576dad..20224796f 100644
--- a/package.json
+++ b/package.json
@@ -121,6 +121,7 @@
     "@storybook/addon-actions": "^3.1.8",
     "@storybook/react": "^3.1.8",
     "babel-eslint": "^7.2.3",
+    "babel-plugin-preval": "^1.3.2",
     "chai": "^4.1.0",
     "chai-enzyme": "^0.8.0",
     "enzyme": "^2.9.1",
diff --git a/spec/javascript/components/emojify.test.js b/spec/javascript/components/emojify.test.js
index e165b4519..2874bb56d 100644
--- a/spec/javascript/components/emojify.test.js
+++ b/spec/javascript/components/emojify.test.js
@@ -22,23 +22,23 @@ describe('emojify', () => {
 
   it('does unicode', () => {
     expect(emojify('\uD83D\uDC69\u200D\uD83D\uDC69\u200D\uD83D\uDC66\u200D\uD83D\uDC66')).to.equal(
-      '<img draggable="false" class="emojione" alt="👩‍👩‍👦‍👦" title=":family_wwbb:" src="/emoji/1f469-1f469-1f466-1f466.svg" />');
+      '<img draggable="false" class="emojione" alt="👩‍👩‍👦‍👦" src="/emoji/1f469-1f469-1f466-1f466.svg" />');
     expect(emojify('\uD83D\uDC68\uD83D\uDC69\uD83D\uDC67\uD83D\uDC67')).to.equal(
-      '<img draggable="false" class="emojione" alt="👨👩👧👧" title=":family_mwgg:" src="/emoji/1f468-1f469-1f467-1f467.svg" />');
-    expect(emojify('\uD83D\uDC69\uD83D\uDC69\uD83D\uDC66')).to.equal('<img draggable="false" class="emojione" alt="👩👩👦" title=":family_wwb:" src="/emoji/1f469-1f469-1f466.svg" />');
+      '<img draggable="false" class="emojione" alt="👨👩👧👧" src="/emoji/1f468-1f469-1f467-1f467.svg" />');
+    expect(emojify('\uD83D\uDC69\uD83D\uDC69\uD83D\uDC66')).to.equal('<img draggable="false" class="emojione" alt="👩👩👦" src="/emoji/1f469-1f469-1f466.svg" />');
     expect(emojify('\u2757')).to.equal(
-      '<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" />');
+      '<img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" />');
   });
 
   it('does multiple unicode', () => {
     expect(emojify('\u2757 #\uFE0F\u20E3')).to.equal(
-      '<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" />');
+      '<img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" src="/emoji/0023-20e3.svg" />');
     expect(emojify('\u2757#\uFE0F\u20E3')).to.equal(
-      '<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /><img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" />');
+      '<img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" /><img draggable="false" class="emojione" alt="#️⃣" src="/emoji/0023-20e3.svg" />');
     expect(emojify('\u2757 #\uFE0F\u20E3 \u2757')).to.equal(
-      '<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" /> <img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" />');
+      '<img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" src="/emoji/0023-20e3.svg" /> <img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" />');
     expect(emojify('foo \u2757 #\uFE0F\u20E3 bar')).to.equal(
-      'foo <img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" /> bar');
+      'foo <img draggable="false" class="emojione" alt="❗" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" src="/emoji/0023-20e3.svg" /> bar');
   });
 
   it('ignores unicode inside of tags', () => {
diff --git a/yarn.lock b/yarn.lock
index 56a9f7798..defd8599f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -681,6 +681,14 @@ babel-plugin-lodash@^3.2.11:
     glob "^7.1.1"
     lodash "^4.17.2"
 
+babel-plugin-preval@^1.3.2:
+  version "1.3.2"
+  resolved "https://registry.yarnpkg.com/babel-plugin-preval/-/babel-plugin-preval-1.3.2.tgz#44192e6e97b58661bf2c5bcae90bba2a366e0134"
+  dependencies:
+    babel-core "^6.25.0"
+    babylon "^6.17.4"
+    require-from-string "^1.2.1"
+
 babel-plugin-react-docgen@^1.5.0:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-react-docgen/-/babel-plugin-react-docgen-1.5.0.tgz#0339717ad51f4a5ce4349330b8266ea5a56f53b4"
@@ -1312,7 +1320,7 @@ babel-types@^6.19.0, babel-types@^6.23.0, babel-types@^6.24.1, babel-types@^6.25
     lodash "^4.2.0"
     to-fast-properties "^1.0.1"
 
-babylon@^6.17.0, babylon@^6.17.2:
+babylon@^6.17.0, babylon@^6.17.2, babylon@^6.17.4:
   version "6.17.4"
   resolved "https://registry.yarnpkg.com/babylon/-/babylon-6.17.4.tgz#3e8b7402b88d22c3423e137a1577883b15ff869a"
 
@@ -6335,7 +6343,7 @@ require-directory@^2.1.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/require-directory/-/require-directory-2.1.1.tgz#8c64ad5fd30dab1c976e2344ffe7f792a6a6df42"
 
-require-from-string@^1.1.0:
+require-from-string@^1.1.0, require-from-string@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/require-from-string/-/require-from-string-1.2.1.tgz#529c9ccef27380adfec9a2f965b649bbee636418"