From 2e5cb930de80e79000887ba02372960fe1efbb20 Mon Sep 17 00:00:00 2001
From: Samuel Attard <samuel.r.attard@gmail.com>
Date: Sun, 25 Mar 2018 15:03:17 +1100
Subject: [PATCH] Provide an easy way to use a local build of Electron (#12426)

* Provide an easy way to use a local build of Electron

For instance from ~/projects/electron/out/D

* document ELECTRON_OVERRIDE_DIST_PATH

* Make the linter happy

* Tweak ELECTRON_OVERRIDE_DIST_PATH docs
---
 .gitignore                        |  7 ++++++-
 docs/api/environment-variables.md | 10 ++++++++++
 npm/index.js                      | 16 ++++++++++++----
 npm/install.js                    |  6 +++---
 4 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/.gitignore b/.gitignore
index 415b319a3..bbfe5148b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,4 +42,9 @@
 /vendor/python_26/
 node_modules/
 SHASUMS256.txt
-**/package-lock.json
+**/package-lock.json
+**/yarn.lock
+
+# npm package
+/npm/dist
+/npm/path.txt
\ No newline at end of file
diff --git a/docs/api/environment-variables.md b/docs/api/environment-variables.md
index a9459ff05..72f75e6b8 100644
--- a/docs/api/environment-variables.md
+++ b/docs/api/environment-variables.md
@@ -85,3 +85,13 @@ This environment variable will not work if the `crashReporter` is started.
 Shows the Windows's crash dialog when Electron crashes.
 
 This environment variable will not work if the `crashReporter` is started.
+
+### `ELECTRON_OVERRIDE_DIST_PATH`
+
+When running from the `electron` package, this variable tells
+the `electron` command to use the specified build of Electron instead of
+the one downloaded by `npm install`. Usage:
+
+```sh
+export ELECTRON_OVERRIDE_DIST_PATH=/Users/username/projects/electron/out/D
+```
diff --git a/npm/index.js b/npm/index.js
index eb480b9e0..b33c9b493 100644
--- a/npm/index.js
+++ b/npm/index.js
@@ -3,8 +3,16 @@ var path = require('path')
 
 var pathFile = path.join(__dirname, 'path.txt')
 
-if (fs.existsSync(pathFile)) {
-  module.exports = path.join(__dirname, fs.readFileSync(pathFile, 'utf-8'))
-} else {
-  throw new Error('Electron failed to install correctly, please delete node_modules/electron and try installing again')
+function getElectronPath () {
+  if (fs.existsSync(pathFile)) {
+    var executablePath = fs.readFileSync(pathFile, 'utf-8')
+    if (process.env.ELECTRON_OVERRIDE_DIST_PATH) {
+      return path.join(process.env.ELECTRON_OVERRIDE_DIST_PATH, executablePath)
+    }
+    return path.join(__dirname, 'dist', executablePath)
+  } else {
+    throw new Error('Electron failed to install correctly, please delete node_modules/electron and try installing again')
+  }
 }
+
+module.exports = getElectronPath()
diff --git a/npm/install.js b/npm/install.js
index 8cb9ed881..41052ac07 100755
--- a/npm/install.js
+++ b/npm/install.js
@@ -52,12 +52,12 @@ function getPlatformPath () {
 
   switch (platform) {
     case 'darwin':
-      return 'dist/Electron.app/Contents/MacOS/Electron'
+      return 'Electron.app/Contents/MacOS/Electron'
     case 'freebsd':
     case 'linux':
-      return 'dist/electron'
+      return 'electron'
     case 'win32':
-      return 'dist/electron.exe'
+      return 'electron.exe'
     default:
       throw new Error('Electron builds are not available on platform: ' + platform)
   }