Use current Safari identity for Google Sheets

Packages/macOS/CmuxBrowser/Sources/CmuxBrowser/BrowserUserAgentPolicy.swift

@@ -57,7 +57,7 @@ public struct BrowserUserAgentPolicy: Sendable {
 
     /// Resolves the browser identity policy for a top-level destination.
     ///
-    /// Google Sheets intentionally uses WebKit's default embedded identity.
+    /// Every web destination receives the current Safari-compatible identity.
     /// Non-web destinations have no applicable user-agent policy.
     ///
     /// - Parameter url: The destination of the top-level navigation.
@@ -68,16 +68,7 @@ public struct BrowserUserAgentPolicy: Sendable {
               scheme == "http" || scheme == "https" else {
             return .notApplicable
         }
-        guard let host = url.host?.lowercased() else {
-            return .custom(safariCompatibleUserAgent)
-        }
-        let isSheetsHost = host == "sheets.google.com" || host == "spreadsheets.google.com"
-        let isSheetsPath = host == "docs.google.com"
-            && url.path.split(separator: "/", omittingEmptySubsequences: true).first?
-                .lowercased() == "spreadsheets"
-        return isSheetsHost || isSheetsPath
-            ? .webKitDefault
-            : .custom(safariCompatibleUserAgent)
+        return .custom(safariCompatibleUserAgent)
     }
 
     /// Parses a numeric dot-separated browser version.

Packages/macOS/CmuxBrowser/Sources/CmuxBrowser/BrowserUserAgentPolicyResolution.swift

@@ -3,9 +3,6 @@ public enum BrowserUserAgentPolicyResolution: Equatable, Sendable {
     /// Use the supplied custom user-agent identity for an HTTP or HTTPS destination.
     case custom(String)
 
-    /// Use WebKit's default embedded identity for an HTTP or HTTPS destination.
-    case webKitDefault
-
     /// User-agent identity does not apply to this non-web destination.
     case notApplicable
 }

Packages/macOS/CmuxBrowser/Tests/CmuxBrowserTests/BrowserUserAgentPolicyTests.swift

@@ -27,14 +27,17 @@ struct BrowserUserAgentPolicyTests {
         #expect(newerPolicy.safariCompatibleUserAgent.contains("Version/27.0 Safari/605.1.15"))
     }
 
-    @Test func googleSheetsKeepsEmbeddedWebKitIdentity() {
+    @Test func googleSheetsReceivesCurrentSafariCompatibleIdentity() {
         let sheetURL = URL(string: "https://docs.google.com/spreadsheets/d/example/edit")!
         let sheetsRedirectURL = URL(string: "https://sheets.google.com/")!
         let legacyRedirectURL = URL(string: "https://spreadsheets.google.com/")!
+        let expectedResolution = BrowserUserAgentPolicyResolution.custom(
+            policy.safariCompatibleUserAgent
+        )
 
-        #expect(policy.resolution(for: sheetURL) == .webKitDefault)
-        #expect(policy.resolution(for: sheetsRedirectURL) == .webKitDefault)
-        #expect(policy.resolution(for: legacyRedirectURL) == .webKitDefault)
+        #expect(policy.resolution(for: sheetURL) == expectedResolution)
+        #expect(policy.resolution(for: sheetsRedirectURL) == expectedResolution)
+        #expect(policy.resolution(for: legacyRedirectURL) == expectedResolution)
     }
 
     @Test func otherGoogleWorkspaceEditorsRemainSafariCompatible() {

Sources/Panels/BrowserNavigationDelegate.swift

@@ -576,8 +576,7 @@ import WebKit
         let replacedNavigation = activeMainFrameNavigation
         let reportReplacementWillStart = willReplaceNavigationForUserAgentPolicy
         return webView.restartNavigationForBrowserUserAgentPolicyIfNeeded(
-            for: navigationAction.request,
-            targetFrameIsMainFrame: navigationAction.targetFrame?.isMainFrame,
+            navigationAction,
             decisionHandler: decisionHandler,
             willRestart: {
                 reportReplacementWillStart?(webView, replacedNavigation)

Sources/Panels/BrowserPopupWindowController.swift

@@ -789,8 +789,7 @@ private class PopupUIDelegate: BrowserPDFPreviewActionUIDelegate {
         }
 
         return webView.restartNavigationForBrowserUserAgentPolicyIfNeeded(
-            for: navigationAction.request,
-            targetFrameIsMainFrame: navigationAction.targetFrame?.isMainFrame,
+            navigationAction,
             decisionHandler: decisionHandler,
             startReplacement: { restartRequest in
                 controller.requestNavigation(restartRequest, in: webView)

Sources/Panels/WKWebView+BrowserUserAgentPolicy.swift

@@ -12,8 +12,6 @@ extension WKWebView {
         switch BrowserUserAgentPolicy.system.resolution(for: url) {
         case .custom(let userAgent):
             resolvedUserAgent = userAgent
-        case .webKitDefault:
-            resolvedUserAgent = nil
         case .notApplicable:
             guard currentUserAgent != nil else { return false }
             customUserAgent = nil
@@ -44,15 +42,14 @@ extension WKWebView {
 
     @MainActor
     func restartNavigationForBrowserUserAgentPolicyIfNeeded(
-        for request: URLRequest,
-        targetFrameIsMainFrame: Bool?,
+        _ navigationAction: WKNavigationAction,
         decisionHandler: (WKNavigationActionPolicy) -> Void,
         willRestart: () -> Void = {},
         startReplacement: (URLRequest) -> Void
     ) -> Bool {
         guard let restartRequest = browserUserAgentPolicyRestartRequest(
-            for: request,
-            targetFrameIsMainFrame: targetFrameIsMainFrame
+            for: navigationAction.request,
+            targetFrameIsMainFrame: navigationAction.targetFrame?.isMainFrame
         ) else {
             return false
         }

cmuxTests/BrowserUserAgentPolicyWebKitTests.swift

@@ -26,9 +26,25 @@ struct BrowserUserAgentPolicyWebKitTests {
         #expect(webView.browserUserAgentPolicyRestartRequest(for: restartRequest) == nil)
     }
 
-    @Test func restartRequestCanRestoreEmbeddedIdentityForSheets() throws {
+    @Test func restartRequestReplacesStaleSheetsIdentity() throws {
+        let webView = WKWebView(frame: .zero, configuration: WKWebViewConfiguration())
+        webView.customUserAgent = "stale-agent"
+        var request = URLRequest(
+            url: URL(string: "https://docs.google.com/spreadsheets/d/example/edit")!
+        )
+        request.setValue("stale-agent", forHTTPHeaderField: "User-Agent")
+
+        let restartRequest = try #require(
+            webView.browserUserAgentPolicyRestartRequest(for: request)
+        )
+
+        #expect(restartRequest.value(forHTTPHeaderField: "User-Agent") == nil)
+        #expect(webView.customUserAgent == BrowserUserAgentPolicy.system.safariCompatibleUserAgent)
+        #expect(webView.browserUserAgentPolicyRestartRequest(for: restartRequest) == nil)
+    }
+
+    @Test func sheetsRequestUsesCurrentSafariForNetworkAndNavigatorIdentity() throws {
         let webView = WKWebView(frame: .zero, configuration: WKWebViewConfiguration())
-        webView.customUserAgent = BrowserUserAgentPolicy.system.safariCompatibleUserAgent
         let request = URLRequest(
             url: URL(string: "https://docs.google.com/spreadsheets/d/example/edit")!
         )
@@ -37,18 +53,25 @@ struct BrowserUserAgentPolicyWebKitTests {
             webView.browserUserAgentPolicyRestartRequest(for: request)
         )
 
-        #expect(webView.customUserAgent?.isEmpty != false)
+        #expect(restartRequest.value(forHTTPHeaderField: "User-Agent") == nil)
+        #expect(webView.customUserAgent == BrowserUserAgentPolicy.system.safariCompatibleUserAgent)
         #expect(webView.browserUserAgentPolicyRestartRequest(for: restartRequest) == nil)
     }
 
-    @Test func emptyCustomUserAgentIsAlreadyEmbeddedIdentityForSheets() {
+    @Test func emptyCustomUserAgentIsNotAcceptedAsSheetsIdentity() throws {
         let webView = WKWebView(frame: .zero, configuration: WKWebViewConfiguration())
         webView.customUserAgent = ""
         let request = URLRequest(
             url: URL(string: "https://docs.google.com/spreadsheets/d/example/edit")!
         )
 
-        #expect(webView.browserUserAgentPolicyRestartRequest(for: request) == nil)
+        let restartRequest = try #require(
+            webView.browserUserAgentPolicyRestartRequest(for: request)
+        )
+
+        #expect(restartRequest.value(forHTTPHeaderField: "User-Agent") == nil)
+        #expect(webView.customUserAgent == BrowserUserAgentPolicy.system.safariCompatibleUserAgent)
+        #expect(webView.browserUserAgentPolicyRestartRequest(for: restartRequest) == nil)
     }
 
     @Test func restartRequestIgnoresSubframesAndNewWindowTargets() throws {
@@ -73,37 +96,4 @@ struct BrowserUserAgentPolicyWebKitTests {
         #expect(webView.browserUserAgentPolicyRestartRequest(for: request) == nil)
         #expect(webView.customUserAgent?.isEmpty != false)
     }
-
-    @Test func sheetsDestinationNeverAllowsStaleSafariIdentity() throws {
-        let webView = WKWebView(frame: .zero, configuration: WKWebViewConfiguration())
-        let request = URLRequest(
-            url: URL(string: "https://docs.google.com/spreadsheets/d/example/edit")!
-        )
-        var decisions: [WKNavigationActionPolicy] = []
-        var replacementRequests: [URLRequest] = []
-
-        webView.customUserAgent = BrowserUserAgentPolicy.system.safariCompatibleUserAgent
-        #expect(webView.restartNavigationForBrowserUserAgentPolicyIfNeeded(
-            for: request,
-            targetFrameIsMainFrame: true,
-            decisionHandler: { decisions.append($0) },
-            startReplacement: { replacementRequests.append($0) }
-        ))
-        #expect(decisions == [.cancel])
-        #expect((webView.customUserAgent ?? "").isEmpty)
-        let replacementRequest = try #require(replacementRequests.first)
-
-        // If another load phase exposes the stale Safari identity again, the
-        // replacement must correct it instead of silently allowing a downgrade.
-        webView.customUserAgent = BrowserUserAgentPolicy.system.safariCompatibleUserAgent
-        #expect(webView.restartNavigationForBrowserUserAgentPolicyIfNeeded(
-            for: replacementRequest,
-            targetFrameIsMainFrame: true,
-            decisionHandler: { decisions.append($0) },
-            startReplacement: { replacementRequests.append($0) }
-        ))
-        #expect(decisions == [.cancel, .cancel])
-        #expect(replacementRequests.count == 2)
-        #expect((webView.customUserAgent ?? "").isEmpty)
-    }
 }