feat: add env variable to skip binary download on npm install (#17627)

* feat: add env variable to skip binary download on npm install

* docs: add "Skip binary download" section to install tutorial

docs/tutorial/installation.md

@@ -97,6 +97,17 @@ a text file. A typical cache might look like this:
 ├── SHASUMS256.txt-1.8.2-beta.3
 ```
 
+## Skip binary download
+When installing the `electron` NPM package, it automatically downloads the electron binary.
+
+This can sometimes be unnecessary, e.g. in a CI environment, when testing another component.
+
+To prevent the binary from being downloaded when you install all npm dependencies you can set the environment variable `ELECTRON_SKIP_BINARY_DOWNLOAD`.
+E.g.:
+```sh
+ELECTRON_SKIP_BINARY_DOWNLOAD=1 npm install
+```
+
 ## Troubleshooting
 
 When running `npm install electron`, some users occasionally encounter

npm/install.js

@@ -15,6 +15,10 @@ try {
   // do nothing
 }
 
+if (process.env.ELECTRON_SKIP_BINARY_DOWNLOAD) {
+  process.exit(0)
+}
+
 var platformPath = getPlatformPath()
 
 var electronPath = process.env.ELECTRON_OVERRIDE_DIST_PATH || path.join(__dirname, 'dist', platformPath)