Moved backend injection logic to content script

packages/react-devtools-extensions/src/inject.js

@@ -1,14 +1,9 @@
 /* global chrome */
 
-export default function inject(scriptName: string, done: ?Function) {
+export default function inject(scriptName: string, done: ? Function) {
   const source = `
-  // the prototype stuff is in case document.createElement has been modified
   (function () {
-    var script = document.constructor.prototype.createElement.call(document, 'script');
-    script.src = "${scriptName}";
-    script.charset = "utf-8";
-    document.documentElement.appendChild(script);
-    script.parentNode.removeChild(script);
+    window.postMessage({ source: 'react-devtools-inject-backend', type: "FROM_PAGE", text: "Hello from the webpage!" }, "*");
   })()
   `;
 
@@ -21,4 +16,4 @@ export default function inject(scriptName: string, done: ?Function) {
       done();
     }
   });
-}
+}

packages/react-devtools-extensions/src/injectGlobalHook.js

@@ -1,9 +1,15 @@
 /* global chrome */
 
 import nullthrows from 'nullthrows';
-import {installHook} from 'react-devtools-shared/src/hook';
-import {SESSION_STORAGE_RELOAD_AND_PROFILE_KEY} from 'react-devtools-shared/src/constants';
-import {sessionStorageGetItem} from 'react-devtools-shared/src/storage';
+import {
+  installHook
+} from 'react-devtools-shared/src/hook';
+import {
+  SESSION_STORAGE_RELOAD_AND_PROFILE_KEY
+} from 'react-devtools-shared/src/constants';
+import {
+  sessionStorageGetItem
+} from 'react-devtools-shared/src/storage';
 
 function injectCode(code) {
   const script = document.createElement('script');
@@ -24,16 +30,21 @@ let lastDetectionResult;
 // So instead, the hook will use postMessage() to pass message to us here.
 // And when this happens, we'll send a message to the "background page".
 window.addEventListener('message', function(evt) {
-  if (
-    evt.source === window &&
-    evt.data &&
-    evt.data.source === 'react-devtools-detector'
-  ) {
-    lastDetectionResult = {
-      hasDetectedReact: true,
-      reactBuildType: evt.data.reactBuildType,
-    };
-    chrome.runtime.sendMessage(lastDetectionResult);
+  if (evt.source === window && evt.data) {
+    if (evt.data.source === 'react-devtools-detector') {
+      lastDetectionResult = {
+        hasDetectedReact: true,
+        reactBuildType: evt.data.reactBuildType,
+      };
+      chrome.runtime.sendMessage(lastDetectionResult);
+    } else if (evt.data.source === 'react-devtools-inject-backend') {
+      //Inject backend
+      var script = document.constructor.prototype.createElement.call(document, 'script');
+      script.src = chrome.runtime.getURL('build/backend.js');
+      script.charset = "utf-8";
+      document.documentElement.appendChild(script);
+      script.parentNode.removeChild(script);
+    }
   }
 });
 
@@ -86,4 +97,4 @@ if (sessionStorageGetItem(SESSION_STORAGE_RELOAD_AND_PROFILE_KEY) === 'true') {
 // devtools are installed (and skip its suggestion to install the devtools).
 injectCode(
   ';(' + installHook.toString() + '(window))' + saveNativeValues + detectReact,
-);
+);