Add FXIOS-11322 #24638 [WebEngine] Native error page handling (#24645)

* Add internal pages management in engine * Handle error and surface error pages request to Client * Try it out in SampleBrowser, fix SampleBrowser to build * Show error page in sample browser * Self review * Add WKInternalSchemeHandlerTests * Added unit tests * Remove unused var * Swiftlint * Add explanations * Use pinToSuperview
mozilla-mobile · Feb 7, 2025 · 054c4ef · 054c4ef
1 parent c2f5244
commit 054c4ef
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Showing 31 changed files with 603 additions and 28 deletions.
diff --git a/BrowserKit/Sources/Common/Extensions/UIViewExtension.swift b/BrowserKit/Sources/Common/Extensions/UIViewExtension.swift
@@ -37,4 +37,16 @@ extension UIView {
     public func addSubviews(_ views: UIView...) {
         views.forEach(addSubview)
     }
+
+    /// Convenience utility for pinning a subview to the bounds of its superview.
+    public func pinToSuperview() {
+        guard let parentView = superview else { return }
+        NSLayoutConstraint.activate([
+            topAnchor.constraint(equalTo: parentView.topAnchor),
+            leadingAnchor.constraint(equalTo: parentView.leadingAnchor),
+            trailingAnchor.constraint(equalTo: parentView.trailingAnchor),
+            bottomAnchor.constraint(equalTo: parentView.bottomAnchor)
+        ])
+        translatesAutoresizingMaskIntoConstraints = false
+    }
 }
diff --git a/BrowserKit/Sources/WebEngine/EngineSession.swift b/BrowserKit/Sources/WebEngine/EngineSession.swift
@@ -74,7 +74,7 @@ public protocol EngineSession {
     func updatePageZoom(_ change: ZoomChangeValue)
 }
 
-extension EngineSession {
+public extension EngineSession {
     func reload(bypassCache: Bool = false) {
         reload(bypassCache: bypassCache)
     }

diff --git a/BrowserKit/Sources/WebEngine/EngineSessionDelegate.swift b/BrowserKit/Sources/WebEngine/EngineSessionDelegate.swift
@@ -28,6 +28,10 @@ public protocol EngineSessionDelegate: AnyObject {
     /// Event to indicate that the page metadata was loaded or updated
     func didLoad(pageMetadata: EnginePageMetadata)
 
+    /// Event to indicate the session encountered an error and a corresponding error page should be shown to the user
+    /// - Parameter error: The error the webpage encountered
+    func onErrorPageRequest(error: NSError)
+
     // MARK: Menu items
     /// Relates to adding native `UIMenuController.shared.menuItems` in webview textfields
 

diff --git a/BrowserKit/Sources/WebEngine/WKWebview/Internal/InternalUtil.swift b/BrowserKit/Sources/WebEngine/WKWebview/Internal/InternalUtil.swift
@@ -0,0 +1,17 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import Foundation
+
+/// Used to setup internal scheme handlers
+struct InternalUtil {
+    func setUpInternalHandlers() {
+        let responders: [(String, WKInternalSchemeResponse)] =
+             [(WKAboutHomeHandler.path, WKAboutHomeHandler()),
+              (WKErrorPageHandler.path, WKErrorPageHandler())]
+        responders.forEach { (path, responder) in
+            WKInternalSchemeHandler.responders[path] = responder
+        }
+    }
+}
diff --git a/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKAboutHomeHandler.swift b/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKAboutHomeHandler.swift
@@ -0,0 +1,25 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import WebKit
+
+class WKAboutHomeHandler: WKInternalSchemeResponse {
+    static let path = "about/home"
+
+    // Return a blank page, the webview delegate will look at the current URL and load the home panel based on that
+    func response(forRequest request: URLRequest) -> (URLResponse, Data)? {
+        guard let url = request.url else { return nil }
+        let response = WKInternalSchemeHandler.response(forUrl: url)
+        // Blank page with a color matching the background of the panels which
+        // is displayed for a split-second until the panel shows.
+        let html = """
+            <!DOCTYPE html>
+            <html>
+              <body></body>
+            </html>
+        """
+        guard let data = html.data(using: .utf8) else { return nil }
+        return (response, data)
+    }
+}
diff --git a/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKErrorPageHandler.swift b/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKErrorPageHandler.swift
@@ -0,0 +1,24 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import WebKit
+
+class WKErrorPageHandler: WKInternalSchemeResponse {
+    static let path = WKInternalURL.Path.errorpage.rawValue
+
+    func response(forRequest request: URLRequest) -> (URLResponse, Data)? {
+        guard let url = request.url else { return nil }
+        let response = WKInternalSchemeHandler.response(forUrl: url)
+        // Blank page with a color matching the background of the panels which
+        // is displayed for a split-second until the panel shows.
+        let html = """
+            <!DOCTYPE html>
+            <html>
+              <body></body>
+            </html>
+        """
+        guard let data = html.data(using: .utf8) else { return nil }
+        return (response, data)
+    }
+}
diff --git a/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKInternalSchemeHandler.swift b/BrowserKit/Sources/WebEngine/WKWebview/Internal/WKInternalSchemeHandler.swift
@@ -0,0 +1,60 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import WebKit
+
+enum WKInternalPageSchemeHandlerError: Error {
+    case badURL
+    case noResponder
+    case responderUnableToHandle
+    case notAuthorized
+}
+
+protocol WKInternalSchemeResponse {
+    func response(forRequest: URLRequest) -> (URLResponse, Data)?
+}
+
+/// Will load resources with URL schemes that WebKit doesn’t handle like homepage and error page.
+class WKInternalSchemeHandler: NSObject, WKURLSchemeHandler {
+    public static let scheme = "internal"
+
+    static func response(forUrl url: URL) -> URLResponse {
+        return URLResponse(url: url, mimeType: "text/html", expectedContentLength: -1, textEncodingName: "utf-8")
+    }
+
+    // Responders are looked up based on the path component, for instance
+    // responder["about/home"] is used for 'internal://local/about/home'
+    static var responders = [String: WKInternalSchemeResponse]()
+
+    func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
+        guard let url = urlSchemeTask.request.url else {
+            urlSchemeTask.didFailWithError(WKInternalPageSchemeHandlerError.badURL)
+            return
+        }
+
+        let path = url.path.starts(with: "/") ? String(url.path.dropFirst()) : url.path
+
+        //  If this is not a homepage or error page
+        if !urlSchemeTask.request.isPrivileged {
+            urlSchemeTask.didFailWithError(WKInternalPageSchemeHandlerError.notAuthorized)
+            return
+        }
+
+        guard let responder = WKInternalSchemeHandler.responders[path] else {
+            urlSchemeTask.didFailWithError(WKInternalPageSchemeHandlerError.noResponder)
+            return
+        }
+
+        guard let (urlResponse, data) = responder.response(forRequest: urlSchemeTask.request) else {
+            urlSchemeTask.didFailWithError(WKInternalPageSchemeHandlerError.responderUnableToHandle)
+            return
+        }
+
+        urlSchemeTask.didReceive(urlResponse)
+        urlSchemeTask.didReceive(data)
+        urlSchemeTask.didFinish()
+    }
+
+    func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {}
+}
diff --git a/...s/WebEngine/WKWebview/WKInternalURL.swift → ...ne/WKWebview/Internal/WKInternalURL.swift b/...s/WebEngine/WKWebview/WKInternalURL.swift → ...ne/WKWebview/Internal/WKInternalURL.swift
diff --git a/BrowserKit/Sources/WebEngine/WKWebview/WKEngine.swift b/BrowserKit/Sources/WebEngine/WKWebview/WKEngine.swift
@@ -13,6 +13,8 @@ public class WKEngine: Engine {
 
     init(userScriptManager: WKUserScriptManager = DefaultUserScriptManager()) {
         self.userScriptManager = userScriptManager
+
+        InternalUtil().setUpInternalHandlers()
     }
 
     public func createView() -> EngineView {

diff --git a/BrowserKit/Sources/WebEngine/WKWebview/WKEngineConfigurationProvider.swift b/BrowserKit/Sources/WebEngine/WKWebview/WKEngineConfigurationProvider.swift
@@ -13,9 +13,21 @@ protocol WKEngineConfigurationProvider {
 struct DefaultWKEngineConfigurationProvider: WKEngineConfigurationProvider {
     func createConfiguration() -> WKEngineConfiguration {
         let configuration = WKWebViewConfiguration()
+        configuration.processPool = WKProcessPool()
+        // TODO: FXIOS-11324 Configure KeyBlockPopups
+//        let blockPopups = prefs?.boolForKey(PrefsKeys.KeyBlockPopups) ?? true
+//        configuration.preferences.javaScriptCanOpenWindowsAutomatically = !blockPopups
         configuration.userContentController = WKUserContentController()
         configuration.allowsInlineMediaPlayback = true
+        // TODO: FXIOS-11324 Configure isPrivate
+//        if isPrivate {
+//            configuration.websiteDataStore = WKWebsiteDataStore.nonPersistent()
+//        } else {
+//            configuration.websiteDataStore = WKWebsiteDataStore.default()
+//        }
 
+        configuration.setURLSchemeHandler(WKInternalSchemeHandler(),
+                                          forURLScheme: WKInternalSchemeHandler.scheme)
         return DefaultEngineConfiguration(webViewConfiguration: configuration)
     }
 }
diff --git a/BrowserKit/Sources/WebEngine/WKWebview/WKEngineSession.swift b/BrowserKit/Sources/WebEngine/WKWebview/WKEngineSession.swift
@@ -9,6 +9,7 @@ import Foundation
 protocol SessionHandler: AnyObject {
     func commitURLChange()
     func fetchMetadata(withURL url: URL)
+    func received(error: NSError, forURL url: URL)
 }
 
 class WKEngineSession: NSObject,
@@ -353,6 +354,11 @@ class WKEngineSession: NSObject,
         metadataFetcher.fetch(fromSession: self, url: url)
     }
 
+    func received(error: NSError, forURL url: URL) {
+        telemetryProxy?.handleTelemetry(event: .showErrorPage(errorCode: error.code))
+        delegate?.onErrorPageRequest(error: error)
+    }
+
     // MARK: - Content scripts
 
     private func addContentScripts() {

diff --git a/BrowserKit/Sources/WebEngine/WKWebview/WKNavigationHandler.swift b/BrowserKit/Sources/WebEngine/WKWebview/WKNavigationHandler.swift
@@ -2,6 +2,7 @@
 // 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/
 
+import Common
 import WebKit
 
 protocol WKNavigationHandler: WKNavigationDelegate {
@@ -51,6 +52,7 @@ protocol WKNavigationHandler: WKNavigationDelegate {
 class DefaultNavigationHandler: NSObject, WKNavigationHandler {
     weak var session: SessionHandler?
     weak var telemetryProxy: EngineTelemetryProxy?
+    var logger: Logger = DefaultLogger.shared
 
     func webView(_ webView: WKWebView,
                  didCommit navigation: WKNavigation?) {
@@ -74,17 +76,43 @@ class DefaultNavigationHandler: NSObject, WKNavigationHandler {
     func webView(_ webView: WKWebView,
                  didFail navigation: WKNavigation?,
                  withError error: Error) {
+        logger.log("Error occurred during navigation.",
+                   level: .warning,
+                   category: .webview)
+
         telemetryProxy?.handleTelemetry(event: .didFailNavigation)
         telemetryProxy?.handleTelemetry(event: .pageLoadCancelled)
-        // TODO: FXIOS-8277 - Determine navigation calls with EngineSessionDelegate
     }
 
     func webView(_ webView: WKWebView,
                  didFailProvisionalNavigation navigation: WKNavigation?,
                  withError error: Error) {
+        logger.log("Error occurred during the early navigation process.",
+                   level: .warning,
+                   category: .webview)
+
         telemetryProxy?.handleTelemetry(event: .didFailProvisionalNavigation)
         telemetryProxy?.handleTelemetry(event: .pageLoadCancelled)
-        // TODO: FXIOS-8277 - Determine navigation calls with EngineSessionDelegate
+
+        // Ignore the "Frame load interrupted" error that is triggered when we cancel a request
+        // to open an external application and hand it over to UIApplication.openURL(). The result
+        // will be that we switch to the external app, for example the app store, while keeping the
+        // original web page in the tab instead of replacing it with an error page.
+        let error = error as NSError
+        if error.domain == "WebKitErrorDomain" && error.code == 102 {
+            return
+        }
+
+        guard !checkIfWebContentProcessHasCrashed(webView, error: error as NSError) else { return }
+
+        if error.code == Int(CFNetworkErrors.cfurlErrorCancelled.rawValue) {
+            session?.commitURLChange()
+            return
+        }
+
+        if let url = error.userInfo[NSURLErrorFailingURLErrorKey] as? URL {
+            session?.received(error: error, forURL: url)
+        }
     }
 
     func webView(_ webView: WKWebView,
@@ -124,4 +152,18 @@ class DefaultNavigationHandler: NSObject, WKNavigationHandler {
         // TODO: FXIOS-8276 - Handle didReceive challenge: URLAuthenticationChallenge (epic part 3)
         completionHandler(.performDefaultHandling, nil)
     }
+
+    // MARK: - Helper methods
+
+    private func checkIfWebContentProcessHasCrashed(_ webView: WKWebView, error: NSError) -> Bool {
+        if error.code == WKError.webContentProcessTerminated.rawValue && error.domain == "WebKitErrorDomain" {
+            logger.log("WebContent process has crashed. Trying to reload to restart it.",
+                       level: .warning,
+                       category: .webview)
+            webView.reload()
+            return true
+        }
+
+        return false
+    }
 }
diff --git a/BrowserKit/Tests/WebEngineTests/Mock/MockEngineSessionDelegate.swift b/BrowserKit/Tests/WebEngineTests/Mock/MockEngineSessionDelegate.swift
@@ -14,6 +14,7 @@ class MockEngineSessionDelegate: EngineSessionDelegate {
     var onLocationChangedCalled = 0
     var onHasOnlySecureContentCalled = 0
     var didLoadPagemetaDataCalled = 0
+    var onErrorPageCalled = 0
     var findInPageCalled = 0
     var searchCalled = 0
     var onProvideContextualMenuCalled = 0
@@ -27,6 +28,7 @@ class MockEngineSessionDelegate: EngineSessionDelegate {
     var savedCanGoForward: Bool?
     var savedLoading: Bool?
     var savedPagemetaData: EnginePageMetadata?
+    var savedError: NSError?
     var savedFindInPageSelection: String?
     var savedSearchSelection: String?
 
@@ -66,6 +68,11 @@ class MockEngineSessionDelegate: EngineSessionDelegate {
         savedPagemetaData = pageMetadata
     }
 
+    func onErrorPageRequest(error: NSError) {
+        savedError = error
+        onErrorPageCalled += 1
+    }
+
     func findInPage(with selection: String) {
         findInPageCalled += 1
         savedFindInPageSelection = selection

diff --git a/BrowserKit/Tests/WebEngineTests/Mock/MockSchemeHandler.swift b/BrowserKit/Tests/WebEngineTests/Mock/MockSchemeHandler.swift
@@ -0,0 +1,14 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import Foundation
+@testable import WebEngine
+
+class MockSchemeHandler: WKInternalSchemeResponse {
+    static let path = "about/test"
+
+    func response(forRequest request: URLRequest) -> (URLResponse, Data)? {
+        return nil
+    }
+}
diff --git a/BrowserKit/Tests/WebEngineTests/Mock/MockSessionHandler.swift b/BrowserKit/Tests/WebEngineTests/Mock/MockSessionHandler.swift
@@ -0,0 +1,29 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// 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/
+
+import Foundation
+@testable import WebEngine
+
+class MockSessionHandler: SessionHandler {
+    var commitURLChangeCalled = 0
+    var fetchMetadataCalled = 0
+    var receivedErrorCalled = 0
+    var savedError: NSError?
+    var savedURL: URL?
+
+    func commitURLChange() {
+        commitURLChangeCalled += 1
+    }
+
+    func fetchMetadata(withURL url: URL) {
+        savedURL = url
+        fetchMetadataCalled += 1
+    }
+
+    func received(error: NSError, forURL url: URL) {
+        savedError = error
+        savedURL = url
+        receivedErrorCalled += 1
+    }
+}
diff --git a/BrowserKit/Tests/WebEngineTests/Mock/MockWKEngineWebView.swift b/BrowserKit/Tests/WebEngineTests/Mock/MockWKEngineWebView.swift
@@ -6,6 +6,8 @@ import UIKit
 import WebKit
 @testable import WebEngine
 
+/// Necessary since some methods of `WKWebView` cannot be overriden. An abstraction need to be used to be able
+/// to mock all methods.
 class MockWKEngineWebView: UIView, WKEngineWebView {
     var delegate: WKEngineWebViewDelegate?
     var uiDelegate: WKUIDelegate?