From 44333c5de324c3896363a2ed1be2b673529f1da6 Mon Sep 17 00:00:00 2001
From: Guo Xiang Tan <tgx_world@hotmail.com>
Date: Fri, 24 Nov 2017 14:57:36 +0800
Subject: [PATCH] REFACTORY: Dry up some composer syncing code.

---
 .../components/composer-editor.js.es6         | 23 +++++++++----------
 .../inject-line-number.js.es6                 |  9 ++++----
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/app/assets/javascripts/discourse/components/composer-editor.js.es6 b/app/assets/javascripts/discourse/components/composer-editor.js.es6
index d2cda54ab69..951e2140eb4 100644
--- a/app/assets/javascripts/discourse/components/composer-editor.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-editor.js.es6
@@ -141,12 +141,7 @@ export default Ember.Component.extend({
       $preview.off('scroll');
 
       $input.on('scroll', () => {
-        if (this.get('shouldBuildScrollMap')) {
-          this.set('scrollMap', this._buildScrollMap($input, $preview));
-          this.set('shouldBuildScrollMap', false);
-        }
-
-        Ember.run.throttle(this, this._syncEditorAndPreviewScroll, $input, $preview, this.get('scrollMap'), 20);
+        this._syncScroll(this._syncEditorAndPreviewScroll, $input, $preview);
       });
     });
 
@@ -154,16 +149,20 @@ export default Ember.Component.extend({
       $input.off('scroll');
 
       $preview.on('scroll', () => {
-        if (this.get('shouldBuildScrollMap')) {
-          this.set('scrollMap', this._buildScrollMap($input, $preview));
-          this.set('shouldBuildScrollMap', false);
-        }
-
-        Ember.run.throttle(this, this._syncPreviewAndEditorScroll, $input, $preview, this.get('scrollMap'), 20);
+        this._syncScroll(this._syncPreviewAndEditorScroll, $input, $preview);
       });
     });
   },
 
+  _syncScroll($callback, $input, $preview) {
+    if (!this.get('scrollMap') || this.get('shouldBuildScrollMap')) {
+      this.set('scrollMap', this._buildScrollMap($input, $preview));
+      this.set('shouldBuildScrollMap', false);
+    }
+
+    Ember.run.throttle(this, $callback, $input, $preview, this.get('scrollMap'), 20);
+  },
+
   _teardownInputPreviewSync() {
     [this.$('.d-editor-input'), this.$('.d-editor-preview')].forEach($element => {
       $element.off("mouseenter touchstart");
diff --git a/app/assets/javascripts/pretty-text/engines/discourse-markdown/inject-line-number.js.es6 b/app/assets/javascripts/pretty-text/engines/discourse-markdown/inject-line-number.js.es6
index 30e4fa84329..eaad9f61b6a 100644
--- a/app/assets/javascripts/pretty-text/engines/discourse-markdown/inject-line-number.js.es6
+++ b/app/assets/javascripts/pretty-text/engines/discourse-markdown/inject-line-number.js.es6
@@ -28,11 +28,12 @@ export function setup(helper) {
     helper.registerPlugin(md => {
       const injectLineNumber = (tokens, index, options, env, self) => {
         let line;
+        const token = tokens[index];
 
-        if (tokens[index].map && tokens[index].level === 0) {
-          line = tokens[index].map[0];
-          tokens[index].attrJoin('class', 'preview-sync-line');
-          tokens[index].attrSet('data-line-number', String(line));
+        if (token.map && token.level === 0) {
+          line = token.map[0];
+          token.attrJoin('class', 'preview-sync-line');
+          token.attrSet('data-line-number', String(line));
         }
 
         return self.renderToken(tokens, index, options, env, self);