🎨 Remove duplication in get preview URL logic

src/app/ui/MusicSelectScene.jsx

@@ -13,6 +13,7 @@ import SceneHeading from 'bemuse/ui/SceneHeading'
 import SceneToolbar from 'bemuse/ui/SceneToolbar'
 import c from 'classnames'
 import compose from 'recompose/compose'
+import getPreviewUrl from 'bemuse/music-collection/getPreviewUrl'
 import online from 'bemuse/online/instance'
 import pure from 'recompose/pure'
 import { OFFICIAL_SERVER_URL } from 'bemuse/music-collection'
@@ -96,9 +97,7 @@ export const MusicSelectScene = React.createClass({
   },
   getPreviewUrl () {
     const song = this.props.musicSelect.song
-    if (!song) return null
-    if (song.tutorial) return null
-    return this.props.collectionUrl + '/' + song.path + '/_bemuse_preview.mp3'
+    return getPreviewUrl(this.props.collectionUrl, song)
   },
   render () {
     let musicSelect = this.props.musicSelect

src/music-collection-viewer/MusicTable.js

@@ -2,6 +2,7 @@ import _ from 'lodash'
 import MusicSelectPreviewer from 'bemuse/music-previewer/MusicSelectPreviewer'
 import React from 'react'
 import getPlayableCharts from 'bemuse/music-collection/getPlayableCharts'
+import getPreviewUrl from 'bemuse/music-collection/getPreviewUrl'
 import groupSongsIntoCategories from 'bemuse/music-collection/groupSongsIntoCategories'
 import sortSongs from 'bemuse/music-collection/sortSongs'
 
@@ -156,7 +157,7 @@ export class MusicTable extends React.Component {
               <span
                 style={{ color: '#8b8685' }}
                 onClick={() => {
-                  const previewUrl = this.props.url + '/' + song.path + '/_bemuse_preview.mp3'
+                  const previewUrl = getPreviewUrl(this.props.url, song)
                   this.setState({ previewUrl })
                 }}
               >{song.genre}</span><br />

src/music-collection/getPreviewUrl.js

@@ -0,0 +1,8 @@
+
+export function getPreviewUrl (serverUrl, song) {
+  if (!song) return null
+  if (song.tutorial) return null
+  return serverUrl + '/' + song.path + '/_bemuse_preview.mp3'
+}
+
+export default getPreviewUrl