From 92e48d411302fe27d7f2a6dc895a15f4bcd4a066 Mon Sep 17 00:00:00 2001
From: Milan Burda <milan.burda@gmail.com>
Date: Thu, 10 Jan 2019 23:59:44 +0100
Subject: [PATCH] fix: BrowserWindow.fromWebContents() can return null

---
 docs/api/browser-window.md           | 3 ++-
 lib/browser/api/browser-window.js    | 2 ++
 spec-main/api-browser-window-spec.ts | 4 ++--
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/docs/api/browser-window.md b/docs/api/browser-window.md
index 117469f20f1de..73bad29f488e4 100644
--- a/docs/api/browser-window.md
+++ b/docs/api/browser-window.md
@@ -658,7 +658,8 @@ Returns `BrowserWindow | null` - The window that is focused in this application,
 
 * `webContents` [WebContents](web-contents.md)
 
-Returns `BrowserWindow` - The window that owns the given `webContents`.
+Returns `BrowserWindow | null` - The window that owns the given `webContents`
+or `null` if the contents are not owned by a window.
 
 #### `BrowserWindow.fromBrowserView(browserView)`
 
diff --git a/lib/browser/api/browser-window.js b/lib/browser/api/browser-window.js
index 939124633be7a..521414fd01bab 100644
--- a/lib/browser/api/browser-window.js
+++ b/lib/browser/api/browser-window.js
@@ -118,6 +118,8 @@ BrowserWindow.fromWebContents = (webContents) => {
   for (const window of BrowserWindow.getAllWindows()) {
     if (window.webContents.equal(webContents)) return window
   }
+
+  return null
 }
 
 BrowserWindow.fromBrowserView = (browserView) => {
diff --git a/spec-main/api-browser-window-spec.ts b/spec-main/api-browser-window-spec.ts
index 03d30154512ae..c768fe91bfed4 100644
--- a/spec-main/api-browser-window-spec.ts
+++ b/spec-main/api-browser-window-spec.ts
@@ -1307,10 +1307,10 @@ describe('BrowserWindow module', () => {
       expect(found.id).to.equal(w.id)
     })
 
-    it('returns undefined for webContents without a BrowserWindow', () => {
+    it('returns null for webContents without a BrowserWindow', () => {
       const contents = (webContents as any).create({})
       try {
-        expect(BrowserWindow.fromWebContents(contents)).to.be.undefined('BrowserWindow.fromWebContents(contents)')
+        expect(BrowserWindow.fromWebContents(contents)).to.be.null('BrowserWindow.fromWebContents(contents)')
       } finally {
         contents.destroy()
       }