React DevTools Extension for Electron

Unfortunately, React DevTools is not working with Electron(<=v1.2.0). Because not implemented chrome.runtime* APIs and not support Background Pages in Electron. So I fix the source of "React DevTools" for Electron.

Installing

npm install --save-dev electron-react-devtools
or
npm install --save-dev firejune/electron-react-devtools

You will still see the React DevTools message('Download the React DevTools and ...') in Console tab.

Then execute the following from the Console tab of your running Electron app's developer tools:

require('electron-react-devtools').install()

And than refresh or restart the renderer process, you can see a React tab added.

To hack on the plugin

• run npm install
• run npm run build in this directory
• run webpack or webpack --watch in this directory
• Go to chrome://extensions, check "developer mode", and click "Load unpacked extension", and select this directory
• Hack away!

Generally, changes to the UI will auto-propagate if you have webpack --watch on (close devtools and re-open them). If you change the background script or injector, you might have to reload the extension from the extensions page.

Insulating the environment

React Devtools has part of the code (the backend + agent) running in the same javascript context as the inspected page, which makes the code vulnerable to environmental inconsistencies. For example, the backend uses the es6 Map class and normally expects it to be available in the global scope. If a user script has overridden this, the backend breaks.

To prevent this, the content script src/GlobalHook.js, which runs before any user js, saves the native values we depend on to the __REACT_DEVTOOLS_GLOBAL_HOOK__ global. These are:

• Set
• Map
• WeakMap
• Object.create

Then in webpack.backend.js, these saved values are substituted for the globally referenced name (e.g. Map gets replaced with window.__REACT_DEVTOOLS_GLOBAL_HOOK__.nativeMap).

Fixing document.create

React Native sets document.createElement to null in order to convince js libs that they are not running in a browser environment while debug in chrome is enabled.

To deal with this, src/inject.js calls document.constructor.prototype.createElement when it needs to create a <script> tag.