Move error definitions to errors.js (#898)

src/renderer/lib/capture-video-frame.js

@@ -1,12 +1,14 @@
 module.exports = captureVideoFrame
 
+const {IllegalArgumentError} = require('./errors')
+
 function captureVideoFrame (video, format) {
   if (typeof video === 'string') {
     video = document.querySelector(video)
   }
 
   if (video == null || video.nodeName !== 'VIDEO') {
-    throw new Error('First argument must be a <video> element or selector')
+    throw new IllegalArgumentError('First argument must be a <video> element or selector')
   }
 
   if (format == null) {
@@ -14,7 +16,7 @@ function captureVideoFrame (video, format) {
   }
 
   if (format !== 'png' && format !== 'jpg' && format !== 'webp') {
-    throw new Error('Second argument must be one of "png", "jpg", or "webp"')
+    throw new IllegalArgumentError('Second argument must be one of "png", "jpg", or "webp"')
   }
 
   const canvas = document.createElement('canvas')

src/renderer/lib/cast.js

@@ -14,6 +14,7 @@ module.exports = {
 }
 
 const config = require('../../config')
+const {CastingError} = require('./errors')
 
 // Lazy load these for a ~300ms improvement in startup time
 let airplayer, chromecasts, dlnacasts
@@ -350,14 +351,16 @@ function toggleMenu (location) {
 
   // Never cast to two devices at the same time
   if (state.playing.location !== 'local') {
-    throw new Error('You can\'t connect to ' + location +
-      ' when already connected to another device')
-  }
+    throw new CastingError(
+      `You can't connect to ${location} when already connected to another device`
+    ) }
 
   // Find all cast devices of the given type
   const player = getPlayer(location)
   const devices = player ? player.getDevices() : []
-  if (devices.length === 0) throw new Error('No ' + location + ' devices available')
+  if (devices.length === 0) {
+    throw new CastingError(`No ${location} devices available`)
+  }
 
   // Show a menu
   state.devices.castMenu = {location, devices}

src/renderer/lib/errors.js

@@ -1,15 +1,54 @@
+const ExtendableError = require('es6-error')
+
+/* Generic errors */
+
+class CastingError extends ExtendableError {}
+class PlaybackError extends ExtendableError {}
+class SoundError extends ExtendableError {}
+class TorrentError extends ExtendableError {}
+
+/* Playback */
+
+class UnplayableTorrentError extends PlaybackError {
+  constructor () { super('Can\'t play any files in torrent') }
+}
+
+class UnplayableFileError extends PlaybackError {
+  constructor () { super('Can\'t play that file') }
+}
+
+class PlaybackTimedOutError extends PlaybackError {
+  constructor () { super('Playback timed out. Try again.') }
+}
+
+/* Sound */
+
+class InvalidSoundNameError extends SoundError {
+  constructor (name) { super(`Invalid sound name: ${name}`) }
+}
+
+/* Torrent */
+
+class TorrentKeyNotFoundError extends TorrentError {
+  constructor (torrentKey) { super(`Can't resolve torrent key ${torrentKey}`) }
+}
+
+class InvalidTorrentError extends TorrentError {}
+
+/* Miscellaneous */
+
+class IllegalArgumentError extends ExtendableError {}
+
 module.exports = {
+  CastingError,
+  PlaybackError,
+  SoundError,
+  TorrentError,
   UnplayableTorrentError,
-  UnplayableFileError
+  UnplayableFileError,
+  PlaybackTimedOutError,
+  InvalidSoundNameError,
+  TorrentKeyNotFoundError,
+  InvalidTorrentError,
+  IllegalArgumentError
 }
-
-function UnplayableTorrentError () {
-  this.message = 'Can\'t play any files in torrent'
-}
-
-function UnplayableFileError () {
-  this.message = 'Can\'t play that file'
-}
-
-UnplayableTorrentError.prototype = Error
-UnplayableFileError.prototype = Error

src/renderer/lib/sound.js

@@ -4,6 +4,7 @@ module.exports = {
 }
 
 const config = require('../../config')
+const {InvalidSoundNameError} = require('./errors')
 const path = require('path')
 
 const VOLUME = 0.15
@@ -62,7 +63,7 @@ function play (name) {
   if (!audio) {
     const sound = sounds[name]
     if (!sound) {
-      throw new Error('Invalid sound name')
+      throw new InvalidSoundNameError(name)
     }
     audio = cache[name] = new window.Audio()
     audio.volume = sound.volume