Bug 1712591 - [devtools] Expose hasNativeConsoleAPI via DOCUMENT_EVENT's dom-complete resource. r=nchevobbe

Differential Revision: https://phabricator.services.mozilla.com/D115824

devtools/server/actors/resources/document-event.js

@@ -36,6 +36,8 @@ class DocumentEventWatcher {
         // This will be `true` when the user selected a document in the frame picker tool,
         // in the toolbox toolbar.
         isFrameSwitching,
+        // This is only passed for dom-complete event
+        hasNativeConsoleAPI,
         // This is only passed for will-navigate event
         newURI,
       } = {}
@@ -57,6 +59,10 @@ class DocumentEventWatcher {
           // only send `newURI` on will navigate so we don't make the payload bigger for
           // other events
           newURI: name === "will-navigate" ? newURI : null,
+          // only send `hasNativeConsoleAPI` on dom complete so we don't make the payload bigger for
+          // other events
+          hasNativeConsoleAPI:
+            name == "dom-complete" ? hasNativeConsoleAPI : null,
         },
       ]);
     };

devtools/server/actors/webconsole/listeners/document-events.js

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/* global XPCNativeWrapper */
+
 "use strict";
 
 const EventEmitter = require("devtools/shared/event-emitter");
@@ -153,7 +155,37 @@ DocumentEventsListener.prototype = {
     // 'complete' and the corresponding readystatechange event is thrown
     const window = event.target.defaultView;
     const time = window.performance.timing.domComplete;
-    this.emit("dom-complete", { time, isFrameSwitching });
+    this.emit("dom-complete", {
+      time,
+      isFrameSwitching,
+      hasNativeConsoleAPI: this.hasNativeConsoleAPI(window),
+    });
+  },
+
+  /**
+   * Tells if the window.console object is native or overwritten by script in
+   * the page.
+   *
+   * @param nsIDOMWindow window
+   *        The window object you want to check.
+   * @return boolean
+   *         True if the window.console object is native, or false otherwise.
+   */
+  hasNativeConsoleAPI(window) {
+    let isNative = false;
+    try {
+      // We are very explicitly examining the "console" property of
+      // the non-Xrayed object here.
+      const console = window.wrappedJSObject.console;
+      // In xpcshell tests, console ends up being undefined and XPCNativeWrapper
+      // crashes in debug builds.
+      if (console) {
+        isNative = new XPCNativeWrapper(console).IS_NATIVE_CONSOLE === true;
+      }
+    } catch (ex) {
+      // ignore
+    }
+    return isNative;
   },
 
   destroy() {

devtools/shared/commands/resource/tests/browser_resources_document_events.js

@@ -8,6 +8,7 @@
 add_task(async function() {
   await testDocumentEventResources();
   await testDocumentEventResourcesWithIgnoreExistingResources();
+  await testDomCompleteWithOverloadedConsole();
 
   // Enable server side target switching for next test
   // as the regression it tracks only occurs with server side target switching enabled
@@ -315,6 +316,36 @@ async function testCrossOriginNavigation() {
   await commands.destroy();
 }
 
+async function testDomCompleteWithOverloadedConsole() {
+  info("Test dom-complete with an overloaded console object");
+
+  const tab = await addTab(
+    "data:text/html,<script>window.console = {};</script>"
+  );
+
+  const { client, resourceCommand, targetCommand } = await initResourceCommand(
+    tab
+  );
+
+  info("Check that all DOCUMENT_EVENTS are fired for the already loaded page");
+  const documentEvents = [];
+  await resourceCommand.watchResources([resourceCommand.TYPES.DOCUMENT_EVENT], {
+    onAvailable: resources => documentEvents.push(...resources),
+  });
+  is(documentEvents.length, 3, "Existing document events are fired");
+
+  const domComplete = documentEvents[2];
+  is(domComplete.name, "dom-complete", "the last resource is the dom-complete");
+  is(
+    domComplete.hasNativeConsoleAPI,
+    false,
+    "the console object is reported to be overloaded"
+  );
+
+  targetCommand.destroy();
+  await client.close();
+}
+
 async function assertPromises(
   commands,
   targetBeforeNavigation,
@@ -428,6 +459,12 @@ function assertEvents(
     currentTargetFront,
     "complete target is the current target"
   );
+
+  is(
+    completeEvent.hasNativeConsoleAPI,
+    true,
+    "None of the tests (except the dedicated one) overload the console object"
+  );
 }
 
 class ResourceListener {