From be0212582613cdd468d608ff81f388232f6815b2 Mon Sep 17 00:00:00 2001
From: Milan Burda <milan.burda@gmail.com>
Date: Sat, 8 Dec 2018 10:41:27 +0100
Subject: [PATCH] return empty instead of error

---
 docs/api/app.md                      |  2 +-
 docs/api/web-contents.md             |  2 +-
 lib/browser/desktop-capturer.js      |  8 +++-----
 lib/renderer/api/desktop-capturer.js | 10 ++++------
 spec/api-desktop-capturer-spec.js    | 18 +++++++++---------
 5 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/docs/api/app.md b/docs/api/app.md
index 5a6c8604ed70d..5a6a1c45c5a71 100644
--- a/docs/api/app.md
+++ b/docs/api/app.md
@@ -409,7 +409,7 @@ Returns:
 * `webContents` [WebContents](web-contents.md)
 
 Emitted when `desktopCapturer.getSources()` is called in the renderer process of `webContents`.
-Calling `event.preventDefault()` will make it throw an error.
+Calling `event.preventDefault()` will make it return empty sources.
 
 ### Event: 'remote-require'
 
diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
index 5bca2bf0d0077..679e61b6b54f8 100644
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -670,7 +670,7 @@ Returns:
 * `event` Event
 
 Emitted when `desktopCapturer.getSources()` is called in the renderer process.
-Calling `event.preventDefault()` will make it throw an error.
+Calling `event.preventDefault()` will make it return empty sources.
 
 #### Event: 'remote-require'
 
diff --git a/lib/browser/desktop-capturer.js b/lib/browser/desktop-capturer.js
index 9bcb005f321d3..fa10803079d21 100644
--- a/lib/browser/desktop-capturer.js
+++ b/lib/browser/desktop-capturer.js
@@ -1,7 +1,6 @@
 'use strict'
 
 const ipcMain = require('@electron/internal/browser/ipc-main-internal')
-const errorUtils = require('@electron/internal/common/error-utils')
 
 const { desktopCapturer } = process.atomBinding('desktop_capturer')
 const eventBinding = process.atomBinding('event')
@@ -19,8 +18,7 @@ ipcMain.on(electronSources, (event, captureWindow, captureScreen, thumbnailSize,
   event.sender.emit('desktop-capturer-get-sources', customEvent)
 
   if (customEvent.defaultPrevented) {
-    const error = new Error('desktopCapturer.getSources() blocked')
-    event.sender._sendInternal(capturerResult(id), errorUtils.serialize(error))
+    event.sender._sendInternal(capturerResult(id), [])
     return
   }
 
@@ -63,7 +61,7 @@ desktopCapturer.emit = (event, name, sources, fetchWindowIcons) => {
   })
 
   if (handledWebContents) {
-    handledWebContents._sendInternal(capturerResult(handledRequest.id), null, result)
+    handledWebContents._sendInternal(capturerResult(handledRequest.id), result)
   }
 
   // Check the queue to see whether there is another identical request & handle
@@ -71,7 +69,7 @@ desktopCapturer.emit = (event, name, sources, fetchWindowIcons) => {
     const webContents = request.webContents
     if (deepEqual(handledRequest.options, request.options)) {
       if (webContents) {
-        webContents._sendInternal(capturerResult(request.id), null, result)
+        webContents._sendInternal(capturerResult(request.id), result)
       }
     } else {
       unhandledRequestsQueue.push(request)
diff --git a/lib/renderer/api/desktop-capturer.js b/lib/renderer/api/desktop-capturer.js
index dcd18f798a02c..da231d45722e0 100644
--- a/lib/renderer/api/desktop-capturer.js
+++ b/lib/renderer/api/desktop-capturer.js
@@ -1,9 +1,7 @@
 'use strict'
 
 const { nativeImage } = require('electron')
-
 const ipcRenderer = require('@electron/internal/renderer/ipc-renderer-internal')
-const errorUtils = require('@electron/internal/common/error-utils')
 
 const includes = [].includes
 let currentId = 0
@@ -46,11 +44,11 @@ exports.getSources = function (options, callback) {
 
   const id = incrementId()
   ipcRenderer.send('ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES', captureWindow, captureScreen, options.thumbnailSize, options.fetchWindowIcons, id)
-  return ipcRenderer.once(`ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_${id}`, (event, error, sources) => {
-    if (error) {
-      callback(errorUtils.deserialize(error))
-    } else {
+  return ipcRenderer.once(`ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_${id}`, (event, sources) => {
+    try {
       callback(null, mapSources(sources))
+    } catch (error) {
+      callback(error)
     }
   })
 }
diff --git a/spec/api-desktop-capturer-spec.js b/spec/api-desktop-capturer-spec.js
index a66c972499661..b0137c3b45ef4 100644
--- a/spec/api-desktop-capturer-spec.js
+++ b/spec/api-desktop-capturer-spec.js
@@ -39,15 +39,6 @@ describe('desktopCapturer', () => {
     })
   })
 
-  it('throws an error when blocked', done => {
-    ipcRenderer.send('handle-next-desktop-capturer-get-sources')
-    desktopCapturer.getSources({ types: ['screen'] }, (error, sources) => {
-      expect(error.message).to.equal('desktopCapturer.getSources() blocked')
-      expect(sources).to.be.undefined()
-      done()
-    })
-  })
-
   it('does not throw an error when called more than once (regression)', (done) => {
     let callCount = 0
     const callback = (error, sources) => {
@@ -108,5 +99,14 @@ describe('desktopCapturer', () => {
       }
       done()
     })
+
+    it('returns empty sources when blocked', done => {
+      ipcRenderer.send('handle-next-desktop-capturer-get-sources')
+      desktopCapturer.getSources({ types: ['screen'] }, (error, sources) => {
+        expect(error).to.be.null()
+        expect(sources).to.be.empty()
+        done()
+      })
+    })
   })
 })