Merge remote-tracking branch 'pnkapadia64/627-co-to-async' into co-merge

src/coming-soon/demo/index.js

@@ -4,7 +4,6 @@ import $ from 'jquery'
 import { Compiler, Notes, Reader, SongInfo, Timing } from 'bms'
 import DndResources from 'bemuse/resources/dnd-resources'
 import SamplingMaster from 'bemuse/sampling-master'
-import co from 'co'
 import ctx from 'bemuse/audio-context'
 
 import template from './template.jade'
@@ -33,56 +32,53 @@ export function main(element) {
   }
 }
 
-// TODO [#627]: Convert the `go` function to async function (instead of using `co`) in src/coming-soon/demo/index.js
-// See issue #575 for more details.
-function go(loader, element) {
+async function go(loader, element) {
   let master = new SamplingMaster(ctx)
   let $log = element.find('.js-log')
   let $play = element.find('.js-play').hide()
   let $sampler = element.find('.js-sampler')
 
-  co(function*() {
-    log('Loading file list')
-    let list = yield loader.fileList
-    let bmsFile = list.filter(f => f.match(/\.(?:bms|bme|bml|pms)$/i))[0]
-    log('Loading ' + bmsFile)
+  log('Loading file list')
+  let list = await loader.fileList
+  let bmsFile = list.filter(f => f.match(/\.(?:bms|bme|bml|pms)$/i))[0]
+  log('Loading ' + bmsFile)
 
-    let arraybuffer = yield (yield loader.file(bmsFile)).read()
-    let buffer = Buffer.from(new Uint8Array(arraybuffer))
-    let text = yield Promise.promisify(Reader.readAsync)(buffer)
-    let chart = Compiler.compile(text).chart
-    var timing = Timing.fromBMSChart(chart)
-    var notes = Notes.fromBMSChart(chart)
-    var info = SongInfo.fromBMSChart(chart)
-    $('<pre wrap></pre>')
-      .text(JSON.stringify(info, null, 2))
-      .appendTo($sampler)
-    log('Loading samples')
-    var samples = yield loadSamples(notes, chart)
-    log('Click the button to play!')
-    yield waitForPlay()
-    void (function() {
-      master.unmute()
-      for (let note of notes.all()) {
-        setTimeout(() => {
-          let sample = samples[note.keysound]
-          if (!sample) {
-            console.log('warn: unknown sample ' + note.keysound)
-            return
-          }
-          let span = $('<span></span>')
-            .text('[' + note.keysound + '] ')
-            .appendTo($sampler)
-          let instance = sample.play()
-          $sampler[0].scrollTop = $sampler[0].scrollHeight
-          instance.onstop = function() {
-            span.addClass('is-off')
-          }
-        }, timing.beatToSeconds(note.beat) * 1000)
-      }
-      return false
-    })()
-  }).done()
+  let loadedFile = await loader.file(bmsFile)
+  let arraybuffer = await loadedFile.read()
+  let buffer = Buffer.from(new Uint8Array(arraybuffer))
+  let text = await Promise.promisify(Reader.readAsync)(buffer)
+  let chart = Compiler.compile(text).chart
+  var timing = Timing.fromBMSChart(chart)
+  var notes = Notes.fromBMSChart(chart)
+  var info = SongInfo.fromBMSChart(chart)
+  $('<pre wrap></pre>')
+    .text(JSON.stringify(info, null, 2))
+    .appendTo($sampler)
+  log('Loading samples')
+  var loadedSamples = await loadSamples(notes, chart)
+  log('Click the button to play!')
+  await waitForPlay()
+  void (function() {
+    master.unmute()
+    for (let note of notes.all()) {
+      setTimeout(() => {
+        let sample = loadedSamples[note.keysound]
+        if (!sample) {
+          console.log('warn: unknown sample ' + note.keysound)
+          return
+        }
+        let span = $('<span></span>')
+          .text('[' + note.keysound + '] ')
+          .appendTo($sampler)
+        let instance = sample.play()
+        $sampler[0].scrollTop = $sampler[0].scrollHeight
+        instance.onstop = function() {
+          span.addClass('is-off')
+        }
+      }, timing.beatToSeconds(note.beat) * 1000)
+    }
+    return false
+  })()
 
   function waitForPlay() {
     return new Promise(function(resolve) {
@@ -98,17 +94,17 @@ function go(loader, element) {
     $log.text(t)
   }
 
-  function loadSamples(notes, chart) {
+  function loadSamples(_notes, _chart) {
     var samples = {}
     var promises = []
     let completed = 0
 
-    for (let note of notes.all()) {
+    for (let note of _notes.all()) {
       let keysound = note.keysound
       if (!(keysound in samples)) {
         samples[keysound] = null
         promises.push(
-          loadKeysound(chart.headers.get('wav' + keysound))
+          loadKeysound(_chart.headers.get('wav' + keysound))
             .then(blob => master.sample(blob))
             .then(sample => (samples[keysound] = sample))
             .catch(e => console.error('Unable to load ' + keysound + ': ' + e))