Merge pull request #95 from gnarf/tests

Tests for GreenPlayer

package.json

@@ -33,8 +33,9 @@
     "babel-preset-env": "^1.6.1",
     "eslint": "^3.19.0",
     "eslint-config-scratch": "^3.1.0",
+    "tap": "^12.0.1",
+    "web-audio-test-api": "^0.5.2",
     "webpack": "^4.8.0",
-    "webpack-cli": "^2.0.15",
+    "webpack-cli": "^2.0.15"
-    "tap": "^12.0.1"
   }
 }

src/AudioEngine.js

@@ -1,4 +1,4 @@
-const StartAudioContext = require('startaudiocontext');
+const StartAudioContext = require('./StartAudioContext');
 const AudioContext = require('audio-context');
 
 const log = require('./log');
@@ -35,13 +35,13 @@ const decodeAudioData = function (audioContext, buffer) {
  * sprites.
  */
 class AudioEngine {
-    constructor () {
+    constructor (audioContext = new AudioContext()) {
         /**
          * AudioContext to play and manipulate sounds with a graph of source
          * and effect nodes.
          * @type {AudioContext}
          */
-        this.audioContext = new AudioContext();
+        this.audioContext = audioContext;
         StartAudioContext(this.audioContext);
 
         /**
@@ -65,6 +65,14 @@ class AudioEngine {
         this.loudness = null;
     }
 
+    /**
+     * Current time in the AudioEngine.
+     * @type {number}
+     */
+    get currentTime () {
+        return this.audioContext.currentTime;
+    }
+
     /**
      * Names of the audio effects.
      * @enum {string}

src/GreenPlayer.js

@@ -27,12 +27,18 @@ class SoundPlayer extends EventEmitter {
         this.buffer = buffer;
 
         this.outputNode = null;
+        this.volumeEffect = null;
         this.target = null;
 
         this.initialized = false;
         this.isPlaying = false;
         this.startingUntil = 0;
         this.playbackRate = 1;
+
+        // handleEvent is a EventTarget api for the DOM, however the web-audio-test-api we use
+        // uses an addEventListener that isn't compatable with object and requires us to pass
+        // this bound function instead
+        this.handleEvent = this.handleEvent.bind(this);
     }
 
     /**
@@ -68,7 +74,7 @@ class SoundPlayer extends EventEmitter {
      */
     _createSource () {
         if (this.outputNode !== null) {
-            this.outputNode.removeEventListener(ON_ENDED, this);
+            this.outputNode.removeEventListener(ON_ENDED, this.handleEvent);
             this.outputNode.disconnect();
         }
 
@@ -76,7 +82,7 @@ class SoundPlayer extends EventEmitter {
         this.outputNode.playbackRate.value = this.playbackRate;
         this.outputNode.buffer = this.buffer;
 
-        this.outputNode.addEventListener(ON_ENDED, this);
+        this.outputNode.addEventListener(ON_ENDED, this.handleEvent);
 
         if (this.target !== null) {
             this.connect(this.target);
@@ -89,8 +95,6 @@ class SoundPlayer extends EventEmitter {
     initialize () {
         this.initialized = true;
 
-        this.volumeEffect = new VolumeEffect(this.audioEngine, this, null);
-
         this._createSource();
     }
 
@@ -112,7 +116,12 @@ class SoundPlayer extends EventEmitter {
             return;
         }
 
-        this.volumeEffect.connect(target);
+        if (this.volumeEffect === null) {
+            this.outputNode.disconnect();
+            this.outputNode.connect(target.getInputNode());
+        } else {
+            this.volumeEffect.connect(target);
+        }
 
         return this;
     }
@@ -127,8 +136,10 @@ class SoundPlayer extends EventEmitter {
 
         this.stopImmediately();
 
-        this.volumeEffect.dispose();
+        if (this.volumeEffect !== null) {
-        this.volumeEffect = null;
+            this.volumeEffect.dispose();
+            this.volumeEffect = null;
+        }
 
         this.outputNode.disconnect();
         this.outputNode = null;
@@ -149,7 +160,7 @@ class SoundPlayer extends EventEmitter {
      */
     take () {
         if (this.outputNode) {
-            this.outputNode.removeEventListener(ON_ENDED, this);
+            this.outputNode.removeEventListener(ON_ENDED, this.handleEvent);
         }
 
         const taken = new SoundPlayer(this.audioEngine, this);
@@ -157,25 +168,22 @@ class SoundPlayer extends EventEmitter {
         if (this.isPlaying) {
             taken.startingUntil = this.startingUntil;
             taken.isPlaying = this.isPlaying;
-            taken.initialize();
+            taken.initialized = this.initialized;
-            taken.outputNode.disconnect();
             taken.outputNode = this.outputNode;
-            taken.outputNode.addEventListener(ON_ENDED, taken);
+            taken.outputNode.addEventListener(ON_ENDED, taken.handleEvent);
-            taken.volumeEffect.set(this.volumeEffect.value);
+            taken.volumeEffect = this.volumeEffect;
+            if (taken.volumeEffect) {
+                taken.volumeEffect.audioPlayer = taken;
+            }
             if (this.target !== null) {
                 taken.connect(this.target);
             }
-        }
 
-        if (this.isPlaying) {
             this.emit('stop');
             taken.emit('play');
         }
 
         this.outputNode = null;
-        if (this.volumeEffect !== null) {
-            this.volumeEffect.dispose();
-        }
         this.volumeEffect = null;
         this.initialized = false;
         this.startingUntil = 0;
@@ -192,23 +200,21 @@ class SoundPlayer extends EventEmitter {
      */
     play () {
         if (this.isStarting) {
+            this.emit('stop');
+            this.emit('play');
             return;
         }
 
         if (this.isPlaying) {
-            // Spawn a Player with the current buffer source, and play for a
+            this.stop();
-            // short period until its volume is 0 and release it to be
-            // eventually garbage collected.
-            this.take().stop();
         }
 
-        if (!this.initialized) {
+        if (this.initialized) {
-            this.initialize();
-        } else {
             this._createSource();
+        } else {
+            this.initialize();
         }
 
-        this.volumeEffect.set(this.volumeEffect.DEFAULT_VALUE);
         this.outputNode.start();
 
         this.isPlaying = true;
@@ -226,13 +232,20 @@ class SoundPlayer extends EventEmitter {
             return;
         }
 
-        this.volumeEffect.set(0);
+        // always do a manual stop on a taken / volume effect fade out sound player
-        this.outputNode.stop(this.audioEngine.audioContext.currentTime + this.audioEngine.DECAY_TIME);
+        // take will emit "stop" as well as reset all of our playing statuses / remove our
+        // nodes / etc
+        const taken = this.take();
+        taken.volumeEffect = new VolumeEffect(taken.audioEngine, taken, null);
 
-        this.isPlaying = false;
+        taken.volumeEffect.connect(taken.target);
-        this.startingUntil = 0;
+        // volumeEffect will recursively connect to us if it needs to, so this happens too:
+        // taken.connect(taken.volumeEffect);
 
-        this.emit('stop');
+        taken.finished().then(() => taken.dispose());
+
+        taken.volumeEffect.set(0);
+        taken.outputNode.stop(this.audioEngine.audioContext.currentTime + this.audioEngine.DECAY_TIME);
     }
 
     /**

src/StartAudioContext.js

@@ -0,0 +1,10 @@
+// StartAudioContext assumes that we are in a window/document setting and messes with the unit
+// tests, this is our own version just checking to see if we have a global document to listen
+// to before we even try to "start" it.  Our test api audio context is started by default.
+const StartAudioContext = require('startaudiocontext');
+
+module.exports = function (context) {
+    if (typeof document !== 'undefined') {
+        return StartAudioContext(context);
+    }
+};

src/effects/Effect.js

@@ -82,14 +82,17 @@ class Effect {
         }
 
         // Store whether the graph should currently affected by this effect.
-        const _isPatch = this._isPatch;
+        const wasPatch = this._isPatch;
+        if (wasPatch) {
+            this._lastPatch = this.audioEngine.currentTime;
+        }
 
         // Call the internal implementation per this Effect.
         this._set(value);
 
         // Connect or disconnect from the graph if this now applies or no longer
         // applies an effect.
-        if (this._isPatch !== _isPatch && this.target !== null) {
+        if (this._isPatch !== wasPatch && this.target !== null) {
             this.connect(this.target);
         }
     }
@@ -133,7 +136,7 @@ class Effect {
             this.outputNode.disconnect();
         }
 
-        if (this._isPatch) {
+        if (this._isPatch || this._lastPatch + this.audioEngine.DECAY_TIME < this.audioEngine.currentTime) {
             this.outputNode.connect(target.getInputNode());
         }
 

src/effects/VolumeEffect.js

@@ -32,13 +32,11 @@ class VolumeEffect extends Effect {
      */
     _set (value) {
         this.value = value;
-        // A gain of 1 is normal. Scale down scratch's volume value. Apply the
+
-        // change over a tiny period of time.
+        const {gain} = this.outputNode;
-        this.outputNode.gain.setTargetAtTime(
+        const {audioContext: {currentTime}, DECAY_TIME} = this.audioEngine;
-            value / 100,
+        gain.setValueAtTime(gain.value, currentTime);
-            this.audioEngine.audioContext.currentTime,
+        gain.linearRampToValueAtTime(value / 100, currentTime + DECAY_TIME);
-            this.audioEngine.DECAY_TIME
-        );
     }
 
     /**

test/AudioEngine.js

@@ -0,0 +1,18 @@
+const tap = require('tap');
+const AudioEngine = require('../src/AudioEngine');
+
+const {AudioContext} = require('web-audio-test-api');
+
+tap.test('AudioEngine', t => {
+    const audioEngine = new AudioEngine(new AudioContext());
+
+    t.plan(1);
+    t.deepEqual(audioEngine.inputNode.toJSON(), {
+        gain: {
+            inputs: [],
+            value: 1
+        },
+        inputs: [],
+        name: 'GainNode'
+    }, 'JSON Representation of inputNode');
+});

test/SoundPlayer.js

@@ -0,0 +1,210 @@
+/* global Uint8Array Promise */
+const tap = require('tap');
+const {AudioContext} = require('web-audio-test-api');
+
+const AudioEngine = require('../src/AudioEngine');
+
+
+tap.test('SoundPlayer', suite => {
+
+    let audioContext;
+    let audioEngine;
+    let soundPlayer;
+
+    const help = {
+        get engineInputs () {
+            return audioEngine.inputNode.toJSON().inputs;
+        }
+    };
+
+    suite.beforeEach(() => {
+        audioContext = new AudioContext();
+        audioEngine = new AudioEngine(audioContext);
+        // sound will be 0.1 seconds long
+        audioContext.DECODE_AUDIO_DATA_RESULT = audioContext.createBuffer(2, 4410, 44100);
+        audioContext.DECODE_AUDIO_DATA_FAILED = false;
+        const data = new Uint8Array(44100);
+        return audioEngine.decodeSoundPlayer({data}).then(result => {
+            soundPlayer = result;
+        });
+    });
+
+    suite.afterEach(() => {
+        soundPlayer.dispose();
+        soundPlayer = null;
+        audioEngine = null;
+        audioContext.$reset();
+        audioContext = null;
+    });
+
+    suite.plan(5);
+
+    suite.test('play initializes and creates source node', t => {
+        t.plan(3);
+        t.equal(soundPlayer.initialized, false, 'not yet initialized');
+        soundPlayer.play();
+        t.equal(soundPlayer.initialized, true, 'now is initialized');
+        t.deepEqual(soundPlayer.outputNode.toJSON(), {
+            buffer: audioContext.DECODE_AUDIO_DATA_RESULT.toJSON(),
+            inputs: [],
+            loop: false,
+            loopEnd: 0,
+            loopStart: 0,
+            name: 'AudioBufferSourceNode',
+            playbackRate: {
+                inputs: [],
+                value: 1
+            }
+        });
+
+        t.end();
+    });
+
+    suite.test('connect', t => {
+        t.plan(1);
+        soundPlayer.play();
+        soundPlayer.connect(audioEngine);
+        t.deepEqual(help.engineInputs, [
+            soundPlayer.outputNode.toJSON()
+        ], 'output node connects to input node');
+        t.end();
+    });
+
+    suite.test('stop decay', t => {
+        t.plan(7);
+        soundPlayer.play();
+        soundPlayer.connect(audioEngine);
+        const outputNode = soundPlayer.outputNode;
+
+        audioContext.$processTo(0);
+        soundPlayer.stop();
+        t.equal(soundPlayer.outputNode, null, 'nullify outputNode immediately (taken sound is stopping)');
+        t.deepEqual(help.engineInputs, [{
+            name: 'GainNode',
+            gain: {
+                value: 1,
+                inputs: []
+            },
+            inputs: [outputNode.toJSON()]
+        }], 'output node connects to gain node to input node');
+
+        audioContext.$processTo(audioEngine.DECAY_TIME / 2);
+        const engineInputs = help.engineInputs;
+        t.notEqual(engineInputs[0].gain.value, 1, 'gain value should not be 1');
+        t.notEqual(engineInputs[0].gain.value, 0, 'gain value should not be 0');
+        t.equal(outputNode.$state, 'PLAYING');
+
+        audioContext.$processTo(audioEngine.DECAY_TIME);
+        t.deepEqual(help.engineInputs, [{
+            name: 'GainNode',
+            gain: {
+                value: 0,
+                inputs: []
+            },
+            inputs: [outputNode.toJSON()]
+        }], 'output node connects to gain node to input node decayed');
+
+        t.equal(outputNode.$state, 'FINISHED');
+
+        t.end();
+    });
+
+    suite.test('play while playing debounces', t => {
+        t.plan(7);
+        const log = [];
+        soundPlayer.connect(audioEngine);
+        soundPlayer.play();
+        t.equal(soundPlayer.isStarting, true, 'player.isStarting');
+        const originalNode = soundPlayer.outputNode;
+        // the second play should still "finish" this play
+        soundPlayer.finished().then(() => log.push('finished first'));
+        soundPlayer.play();
+        soundPlayer.finished().then(() => log.push('finished second'));
+        soundPlayer.play();
+        soundPlayer.finished().then(() => log.push('finished third'));
+        soundPlayer.play();
+        t.equal(originalNode, soundPlayer.outputNode, 'same output node');
+        t.equal(soundPlayer.outputNode.$state, 'PLAYING');
+        return Promise.resolve().then(() => {
+            t.deepEqual(log, ['finished first', 'finished second', 'finished third'], 'finished in order');
+
+            // fast forward to one ms before decay time
+            audioContext.$processTo(audioEngine.DECAY_TIME - 0.001);
+            soundPlayer.play();
+
+            t.equal(originalNode, soundPlayer.outputNode, 'same output node');
+
+
+            // now at DECAY_TIME, we should meet a new player as the old one is taken/stopped
+            audioContext.$processTo(audioEngine.DECAY_TIME);
+
+            t.equal(soundPlayer.isStarting, false, 'player.isStarting now false');
+
+            soundPlayer.play();
+            t.notEqual(originalNode, soundPlayer.outputNode, 'New output node');
+
+            t.end();
+        });
+
+    });
+
+    suite.test('play while playing', t => {
+        t.plan(15);
+        const log = [];
+        soundPlayer.play();
+        soundPlayer.finished().then(() => log.push('play 1 finished'));
+        soundPlayer.connect(audioEngine);
+        const firstPlayNode = soundPlayer.outputNode;
+
+        // go past debounce time and play again
+        audioContext.$processTo(audioEngine.DECAY_TIME);
+
+        return Promise.resolve()
+        .then(() => {
+
+            t.equal(soundPlayer.outputNode.$state, 'PLAYING');
+
+            soundPlayer.play();
+            soundPlayer.finished().then(() => log.push('play 2 finished'));
+
+            // wait for a micro-task loop to fire our previous events
+            return Promise.resolve();
+        })
+        .then(() => {
+
+            t.equal(log[0], 'play 1 finished');
+            t.notEqual(soundPlayer.outputNode, firstPlayNode, 'created new player node');
+
+            t.equal(help.engineInputs.length, 2, 'there should be 2 players connected');
+            t.equal(firstPlayNode.$state, 'PLAYING');
+            t.equal(soundPlayer.outputNode.$state, 'PLAYING');
+            t.equal(help.engineInputs[0].gain.value, 1, 'old sound connectect to gain node with volume 1');
+
+            audioContext.$processTo(audioContext.currentTime + 0.001);
+            t.notEqual(help.engineInputs[0].gain.value, 1,
+            'old sound connected to gain node which will fade');
+
+            audioContext.$processTo(audioContext.currentTime + audioEngine.DECAY_TIME + 0.001);
+            t.equal(soundPlayer.outputNode.$state, 'PLAYING');
+            t.equal(firstPlayNode.$state, 'FINISHED');
+
+            t.equal(help.engineInputs[0].gain.value, 0, 'faded old sound to 0');
+
+            t.equal(log.length, 1);
+            audioContext.$processTo(audioContext.currentTime + 0.2);
+
+            // wait for a micro-task loop to fire our previous events
+            return Promise.resolve();
+        })
+        .then(() => {
+
+            t.equal(log[1], 'play 2 finished');
+            t.equal(help.engineInputs.length, 1, 'old sound disconneted itself after done');
+            t.equal(log.length, 2);
+
+            t.end();
+        });
+    });
+
+    suite.end();
+});

test/__mocks__/AudioParam.js

@@ -2,6 +2,12 @@ class AudioParamMock {
     setTargetAtTime (value /* , start, stop */) {
         this.value = value;
     }
+    setValueAtTime (value) {
+        this.value = value;
+    }
+    linearRampToValueAtTime (value) {
+        this.value = value;
+    }
 }
 
 module.exports = AudioParamMock;