fix(extensions): devtools now open for background pages

refactor(extensions): remove unused InitWithBrowserContext method

fix(extensions): release background page WebContents to avoid crash

The background page WebContents instance is managed by the ExtensionHost.

fix(extensions): open background page devtools detached by default

test(extensions): add background page devtools test

chore: test fix for null web_contents()

fix: close background page devtools in test after opening

shell/browser/api/electron_api_web_contents.cc

@@ -116,6 +116,7 @@
 
 #if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
 #include "extensions/browser/script_executor.h"
+#include "extensions/browser/view_type_utils.h"
 #include "shell/browser/extensions/electron_extension_web_contents_observer.h"
 #endif
 
@@ -376,21 +377,49 @@ base::string16 GetDefaultPrinterAsync() {
 
 }  // namespace
 
+#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+
+WebContents::Type GetTypeFromViewType(extensions::ViewType view_type) {
+  switch (view_type) {
+    case extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE:
+      return WebContents::Type::BACKGROUND_PAGE;
+
+    case extensions::VIEW_TYPE_APP_WINDOW:
+    case extensions::VIEW_TYPE_COMPONENT:
+    case extensions::VIEW_TYPE_EXTENSION_DIALOG:
+    case extensions::VIEW_TYPE_EXTENSION_POPUP:
+    case extensions::VIEW_TYPE_BACKGROUND_CONTENTS:
+    case extensions::VIEW_TYPE_EXTENSION_GUEST:
+    case extensions::VIEW_TYPE_TAB_CONTENTS:
+    case extensions::VIEW_TYPE_INVALID:
+      return WebContents::Type::REMOTE;
+  }
+}
+
+#endif
+
 WebContents::WebContents(v8::Isolate* isolate,
                          content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       type_(Type::REMOTE),
       weak_factory_(this) {
-  web_contents->SetUserAgentOverride(GetBrowserContext()->GetUserAgent(),
-                                     false);
-  Init(isolate);
-  AttachAsUserData(web_contents);
-  InitZoomController(web_contents, gin::Dictionary::CreateEmpty(isolate));
 #if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+  // WebContents created by extension host will have valid ViewType set.
+  extensions::ViewType view_type = extensions::GetViewType(web_contents);
+  if (view_type != extensions::VIEW_TYPE_INVALID) {
+    InitWithExtensionView(isolate, web_contents, view_type);
+  }
+
   extensions::ElectronExtensionWebContentsObserver::CreateForWebContents(
       web_contents);
   script_executor_.reset(new extensions::ScriptExecutor(web_contents));
 #endif
+
+  web_contents->SetUserAgentOverride(GetBrowserContext()->GetUserAgent(),
+                                     false);
+  Init(isolate);
+  AttachAsUserData(web_contents);
+  InitZoomController(web_contents, gin::Dictionary::CreateEmpty(isolate));
   registry_.AddInterface(base::BindRepeating(&WebContents::BindElectronBrowser,
                                              base::Unretained(this)));
   bindings_.set_connection_error_handler(base::BindRepeating(
@@ -579,12 +608,38 @@ void WebContents::InitWithSessionAndOptions(
   AttachAsUserData(web_contents());
 }
 
+#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+void WebContents::InitWithExtensionView(v8::Isolate* isolate,
+                                        content::WebContents* web_contents,
+                                        extensions::ViewType view_type) {
+  // Must reassign type prior to calling `Init`.
+  type_ = GetTypeFromViewType(view_type);
+  if (GetType() == Type::REMOTE)
+    return;
+
+  // Allow toggling DevTools for background pages
+  Observe(web_contents);
+  InitWithWebContents(web_contents, GetBrowserContext(), IsGuest());
+  managed_web_contents()->GetView()->SetDelegate(this);
+  SecurityStateTabHelper::CreateForWebContents(web_contents);
+}
+#endif
+
 WebContents::~WebContents() {
   // The destroy() is called.
   if (managed_web_contents()) {
-    managed_web_contents()->GetView()->SetDelegate(nullptr);
+#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+    if (type_ == Type::BACKGROUND_PAGE) {
+      // Background pages are owned by extensions::ExtensionHost
+      managed_web_contents()->ReleaseWebContents();
+    }
+#endif
 
-    RenderViewDeleted(web_contents()->GetRenderViewHost());
+    managed_web_contents()->GetView()->SetDelegate(nullptr);
+
+    if (web_contents()) {
+      RenderViewDeleted(web_contents()->GetRenderViewHost());
+    }
 
     if (type_ == Type::BROWSER_WINDOW && owner_window()) {
       // For BrowserWindow we should close the window and clean up everything
@@ -1261,6 +1316,7 @@ void WebContents::DevToolsFocused() {
 void WebContents::DevToolsOpened() {
   v8::Locker locker(isolate());
   v8::HandleScope handle_scope(isolate());
+  DCHECK(managed_web_contents());
   auto handle =
       FromOrCreate(isolate(), managed_web_contents()->GetDevToolsWebContents());
   devtools_web_contents_.Reset(isolate(), handle.ToV8());
@@ -1573,7 +1629,8 @@ void WebContents::OpenDevTools(gin_helper::Arguments* args) {
     return;
 
   std::string state;
-  if (type_ == Type::WEB_VIEW || !owner_window()) {
+  if (type_ == Type::WEB_VIEW || type_ == Type::BACKGROUND_PAGE ||
+      !owner_window()) {
     state = "detach";
   }
   bool activate = true;
@@ -1584,6 +1641,8 @@ void WebContents::OpenDevTools(gin_helper::Arguments* args) {
       options.Get("activate", &activate);
     }
   }
+
+  DCHECK(managed_web_contents());
   managed_web_contents()->SetDockState(state);
   managed_web_contents()->ShowDevTools(activate);
 }
@@ -1592,20 +1651,23 @@ void WebContents::CloseDevTools() {
   if (type_ == Type::REMOTE)
     return;
 
+  DCHECK(managed_web_contents());
   managed_web_contents()->CloseDevTools();
 }
 
 bool WebContents::IsDevToolsOpened() {
   if (type_ == Type::REMOTE)
     return false;
 
+  DCHECK(managed_web_contents());
   return managed_web_contents()->IsDevToolsViewShowing();
 }
 
 bool WebContents::IsDevToolsFocused() {
   if (type_ == Type::REMOTE)
     return false;
 
+  DCHECK(managed_web_contents());
   return managed_web_contents()->GetView()->IsDevToolsViewFocused();
 }
 
@@ -1614,6 +1676,7 @@ void WebContents::EnableDeviceEmulation(
   if (type_ == Type::REMOTE)
     return;
 
+  DCHECK(web_contents());
   auto* frame_host = web_contents()->GetMainFrame();
   if (frame_host) {
     auto* widget_host =
@@ -1629,6 +1692,7 @@ void WebContents::DisableDeviceEmulation() {
   if (type_ == Type::REMOTE)
     return;
 
+  DCHECK(web_contents());
   auto* frame_host = web_contents()->GetMainFrame();
   if (frame_host) {
     auto* widget_host =
@@ -1654,6 +1718,7 @@ void WebContents::InspectElement(int x, int y) {
   if (!enable_devtools_)
     return;
 
+  DCHECK(managed_web_contents());
   if (!managed_web_contents()->GetDevToolsWebContents())
     OpenDevTools(nullptr);
   managed_web_contents()->InspectElement(x, y);

shell/browser/api/electron_api_web_contents.h

@@ -42,6 +42,8 @@
 #endif
 
 #if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+#include "extensions/common/view_type.h"
+
 namespace extensions {
 class ScriptExecutor;
 }
@@ -98,7 +100,7 @@ class WebContents : public gin_helper::TrackableObject<WebContents>,
                     public mojom::ElectronBrowser {
  public:
   enum class Type {
-    BACKGROUND_PAGE,  // A DevTools extension background page.
+    BACKGROUND_PAGE,  // An extension background page.
     BROWSER_WINDOW,   // Used by BrowserWindow.
     BROWSER_VIEW,     // Used by BrowserView.
     REMOTE,           // Thin wrap around an existing WebContents.
@@ -373,6 +375,12 @@ class WebContents : public gin_helper::TrackableObject<WebContents>,
       gin::Handle<class Session> session,
       const gin_helper::Dictionary& options);
 
+#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+  void InitWithExtensionView(v8::Isolate* isolate,
+                             content::WebContents* web_contents,
+                             extensions::ViewType view_type);
+#endif
+
   // content::WebContentsDelegate:
   bool DidAddMessageToConsole(content::WebContents* source,
                               blink::mojom::ConsoleMessageLevel level,

shell/browser/extensions/electron_extensions_browser_client.h

@@ -31,8 +31,6 @@ namespace electron {
 
 // An ExtensionsBrowserClient that supports a single content::BrowserContext
 // with no related incognito context.
-// Must be initialized via InitWithBrowserContext() once the BrowserContext is
-// created.
 class ElectronExtensionsBrowserClient
     : public extensions::ExtensionsBrowserClient {
  public:
@@ -121,11 +119,6 @@ class ElectronExtensionsBrowserClient
       content::RenderFrameHost* render_frame_host,
       const extensions::Extension* extension) const override;
 
-  // |context| is the single BrowserContext used for IsValidContext().
-  // |pref_service| is used for GetPrefServiceForContext().
-  void InitWithBrowserContext(content::BrowserContext* context,
-                              PrefService* pref_service);
-
   // Sets the API client.
   void SetAPIClientForTest(extensions::ExtensionsAPIClient* api_client);
 

spec-main/extensions-spec.ts

@@ -262,6 +262,18 @@ ifdescribe(process.electronBinding('features').isExtensionsEnabled())('chrome ex
       const receivedMessage = await w.webContents.executeJavaScript(`window.completionPromise`)
       expect(receivedMessage).to.deep.equal({ some: 'message' })
     })
+
+    it('can open devtools of background page', async () => {
+      const customSession = session.fromPartition(`persist:${require('uuid').v4()}`)
+      await customSession.loadExtension(path.join(fixtures, 'extensions', 'persistent-background-page'))
+      const w = new BrowserWindow({ show: false, webPreferences: { session: customSession } })
+      const promise = emittedOnce(app, 'web-contents-created')
+      await w.loadURL(`about:blank`)
+      const [, bgPageContents] = await promise
+      expect(bgPageContents.getType()).to.equal('backgroundPage')
+      bgPageContents.openDevTools()
+      bgPageContents.closeDevTools()
+    })
   })
 
   describe('devtools extensions', () => {

spec-main/fixtures/extensions/persistent-background-page/background.js

@@ -0,0 +1 @@
+/* eslint-disable no-undef */

spec-main/fixtures/extensions/persistent-background-page/manifest.json

@@ -0,0 +1,9 @@
+{
+  "name": "persistent-background-page",
+  "version": "1.0",
+  "background": {
+    "scripts": ["background.js"],
+    "persistent": true
+  },
+  "manifest_version": 2
+}