fix(browser): open WhatsApp Web in the browser

apps/desktop/src/preview/BrowserSession.test.ts

@@ -16,6 +16,9 @@ const { fromPartition, sessions } = vi.hoisted(() => ({
       readonly setPermissionRequestHandler: ReturnType<typeof vi.fn>;
       readonly setPermissionCheckHandler: ReturnType<typeof vi.fn>;
       readonly setUserAgent: ReturnType<typeof vi.fn>;
+      // SCIENT-FORK:START — Scient Browser: site identity hook.
+      readonly webRequest: { readonly onBeforeSendHeaders: ReturnType<typeof vi.fn> };
+      // SCIENT-FORK:END
     }
   >(),
 }));
@@ -63,6 +66,9 @@ describe("BrowserSession", () => {
         setPermissionRequestHandler: vi.fn(),
         setPermissionCheckHandler: vi.fn(),
         setUserAgent: vi.fn(),
+        // SCIENT-FORK:START — Scient Browser: site identity hook.
+        webRequest: { onBeforeSendHeaders: vi.fn() },
+        // SCIENT-FORK:END
       };
       sessions.set(partition, browserSession);
       return browserSession;
@@ -142,6 +148,9 @@ describe("BrowserSession", () => {
           setUserAgent: vi.fn((next: string) => {
             userAgent = next;
           }),
+          // SCIENT-FORK:START — Scient Browser: site identity hook.
+          webRequest: { onBeforeSendHeaders: vi.fn() },
+          // SCIENT-FORK:END
         };
         sessions.set(partition, browserSession);
         return browserSession;
@@ -157,6 +166,25 @@ describe("BrowserSession", () => {
     }).pipe(Effect.provide(layer)),
   );
 
+  // SCIENT-FORK:START — Scient Browser: site identity hook.
+  it.effect("adds the site identity rule to every browser session", () =>
+    Effect.gen(function* () {
+      const browserSessions = yield* BrowserSession.BrowserSession;
+      const persistent = yield* browserSessions.getPartition("scope-a");
+      const incognito = yield* browserSessions.getPartition("scope-a", false);
+      yield* browserSessions.getSession("scope-a");
+      yield* browserSessions.getSession("scope-a", false);
+
+      for (const partition of [persistent, incognito]) {
+        assert.strictEqual(
+          sessions.get(partition)?.webRequest.onBeforeSendHeaders.mock.calls.length,
+          1,
+        );
+      }
+    }).pipe(Effect.provide(layer)),
+  );
+  // SCIENT-FORK:END
+
   it.effect("grants preview permissions through both the request and check handlers", () =>
     Effect.gen(function* () {
       const browserSessions = yield* BrowserSession.BrowserSession;

apps/desktop/src/preview/BrowserSession.ts

@@ -14,6 +14,9 @@ import * as ElectronDialog from "../electron/ElectronDialog.ts";
 // SCIENT-FORK:START — Scient Accounts: sign-ins outlive the app.
 import { keepSessionCookies } from "../scient/accounts/keepSessionCookies.ts";
 // SCIENT-FORK:END
+// SCIENT-FORK:START — Scient Browser: sites that refuse an app's name open normally.
+import { matchSiteBrowserIdentity } from "../scient/browser/siteBrowserIdentity.ts";
+// SCIENT-FORK:END
 
 const PREVIEW_PARTITION_PREFIX = SCIENT_DESKTOP_IDENTITY.previewPartitionPrefix;
 /** Ephemeral partitions omit persist: but retain a product prefix so the webview gate recognizes them. */
@@ -292,6 +295,9 @@ export const make = Effect.gen(function* BrowserSessionMake() {
           // SCIENT-FORK:START — Scient Accounts: sign-ins outlive the app.
           if (persistent) keepSessionCookies(browserSession);
           // SCIENT-FORK:END
+          // SCIENT-FORK:START — Scient Browser: sites that refuse an app's name open normally.
+          matchSiteBrowserIdentity(browserSession);
+          // SCIENT-FORK:END
           // Like Chrome, clipboard reads ask once per origin; both answers last for the session.
           const clipboardReadDecisions = new Map<string, boolean>();
           const confirmClipboardRead = (

apps/desktop/src/scient/browser/siteBrowserIdentity.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it, vi } from "vite-plus/test";
+
+import { matchSiteBrowserIdentity, withoutAppName } from "./siteBrowserIdentity.ts";
+
+const prefix =
+  "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko)";
+const engine = "Chrome/152.0.7977.169 Electron/44.10.0 Safari/537.36";
+
+function listen() {
+  const onBeforeSendHeaders = vi.fn();
+  matchSiteBrowserIdentity({ webRequest: { onBeforeSendHeaders } } as never);
+  const [filter, listener] = onBeforeSendHeaders.mock.calls[0]!;
+  return { filter, listener };
+}
+
+describe("withoutAppName", () => {
+  it.each(["Scient/0.6.26", "Scient/0.6.27-beta.20261101.1", "ScientDev/44.10.0"])(
+    "removes %s and keeps Chrome and Electron",
+    (token) => {
+      expect(withoutAppName(`${prefix} ${token} ${engine}`)).toBe(`${prefix} ${engine}`);
+    },
+  );
+
+  it("leaves an identity without an app name alone", () => {
+    expect(withoutAppName(`${prefix} ${engine}`)).toBe(`${prefix} ${engine}`);
+  });
+});
+
+describe("matchSiteBrowserIdentity", () => {
+  it("applies to WhatsApp Web only, so other sites keep the native identity", () => {
+    expect(listen().filter).toEqual({ urls: ["*://web.whatsapp.com/*"] });
+  });
+
+  it("changes the identity and keeps the other headers", () => {
+    const callback = vi.fn();
+    listen().listener(
+      { requestHeaders: { Accept: "text/html", "User-Agent": `${prefix} Scient/1.0.0 ${engine}` } },
+      callback,
+    );
+    expect(callback).toHaveBeenCalledWith({
+      requestHeaders: { Accept: "text/html", "User-Agent": `${prefix} ${engine}` },
+    });
+  });
+
+  it("passes a request without an identity through", () => {
+    const callback = vi.fn();
+    listen().listener({ requestHeaders: { Accept: "text/html" } }, callback);
+    expect(callback).toHaveBeenCalledWith({ requestHeaders: { Accept: "text/html" } });
+  });
+});

apps/desktop/src/scient/browser/siteBrowserIdentity.ts

@@ -0,0 +1,28 @@
+import type { Session } from "electron";
+
+/**
+ * Sites that refuse any browser naming an app before or after Chrome, even a current one. Keep this
+ * list short: Cloudflare Turnstile loops on some rewritten identities, so every other site keeps
+ * Electron's native one. WhatsApp decides on the server, so the request header is enough.
+ */
+const SITES_REFUSING_APP_NAME = ["*://web.whatsapp.com/*"];
+
+/** Electron's native identity without the `<App>/<version>` token in front of `Chrome/`. */
+export function withoutAppName(userAgent: string): string {
+  return userAgent.replace(/ [^\s/]+\/\S+(?= Chrome\/)/, "");
+}
+
+export function matchSiteBrowserIdentity(session: Pick<Session, "webRequest">) {
+  session.webRequest.onBeforeSendHeaders(
+    { urls: SITES_REFUSING_APP_NAME },
+    ({ requestHeaders }, callback) => {
+      const userAgent = requestHeaders["User-Agent"];
+      callback({
+        requestHeaders:
+          userAgent === undefined
+            ? requestHeaders
+            : { ...requestHeaders, "User-Agent": withoutAppName(userAgent) },
+      });
+    },
+  );
+}