fix: resolve invite downloads by platform (#2001)

Signed-off-by: npub1dccv64krpcpse5cmkzfeh998cftungyatw3djt8jwdw6g43f7fyqzzmrf7 <6e30cd56c30e030cd31bb0939b94a7c257c9a09d5ba2d92cf2735da45629f248@sprout-oss.stage.blox.sqprod.co>
Co-authored-by: npub1dccv64krpcpse5cmkzfeh998cftungyatw3djt8jwdw6g43f7fyqzzmrf7 <6e30cd56c30e030cd31bb0939b94a7c257c9a09d5ba2d92cf2735da45629f248@sprout-oss.stage.blox.sqprod.co>

web/src/features/invite/ui/InvitePage.tsx

@@ -1,4 +1,8 @@
 import buzzAppIcon from "@/assets/app-icon@3x.png";
+import {
+  BUZZ_RELEASES_URL,
+  resolveBuzzDownloadUrl,
+} from "@/shared/lib/buzz-download";
 import { relayWsUrl } from "@/shared/lib/relay-url";
 import { Button } from "@/shared/ui/button";
 import * as React from "react";
@@ -7,7 +11,6 @@ import remarkGfm from "remark-gfm";
 
 import { InviteJoinPolicyNotice } from "./InviteJoinPolicyNotice";
 
-const DOWNLOAD_URL = "https://github.com/block/buzz/releases/latest";
 type JoinPolicy = {
   terms_markdown?: string;
   privacy_markdown?: string;
@@ -28,6 +31,11 @@ export function InvitePage({ code }: { code: string }) {
   const [ageConfirmed, setAgeConfirmed] = React.useState(false);
   const [agreementConfirmed, setAgreementConfirmed] = React.useState(false);
   const [opening, setOpening] = React.useState(false);
+  const [downloadUrl, setDownloadUrl] = React.useState(BUZZ_RELEASES_URL);
+
+  React.useEffect(() => {
+    resolveBuzzDownloadUrl().then(setDownloadUrl);
+  }, []);
 
   React.useEffect(() => {
     fetch("/api/join-policy")
@@ -150,7 +158,7 @@ export function InvitePage({ code }: { code: string }) {
           Don't have the app?{" "}
           <a
             className="ml-1 font-medium text-black underline-offset-4 hover:text-black/70 hover:underline focus-visible:underline"
-            href={DOWNLOAD_URL}
+            href={downloadUrl}
             rel="noreferrer"
             target="_blank"
           >

web/src/shared/lib/buzz-download.ts

@@ -0,0 +1,190 @@
+export const BUZZ_RELEASES_URL = "https://github.com/block/buzz/releases";
+const BUZZ_RELEASES_API_URL =
+  "https://api.github.com/repos/block/buzz/releases?per_page=10";
+const CACHE_KEY = "buzz.latestDownload.v1";
+const CACHE_TTL_MS = 60 * 60 * 1000;
+
+export type BuzzDownloadPlatform = {
+  operatingSystem: "linux" | "macos" | "windows" | "unknown";
+  architecture: "arm64" | "x64" | "unknown";
+};
+
+type GitHubRelease = {
+  draft: boolean;
+  prerelease: boolean;
+  assets: Array<{ name: string; browser_download_url: string }>;
+};
+
+type UserAgentData = {
+  platform?: string;
+  mobile?: boolean;
+  getHighEntropyValues?: (
+    hints: string[],
+  ) => Promise<{ architecture?: string; bitness?: string }>;
+};
+
+function normalizeOperatingSystem(
+  navigatorValue: Navigator,
+  userAgentData?: UserAgentData,
+): BuzzDownloadPlatform["operatingSystem"] {
+  const userAgent = navigatorValue.userAgent.toLowerCase();
+  const platform = (
+    userAgentData?.platform ??
+    navigatorValue.platform ??
+    ""
+  ).toLowerCase();
+
+  // Compatibility tokens are treacherous: iPadOS can report MacIntel and a
+  // Macintosh UA, while Android and ChromeOS expose Linux platform strings.
+  // Reject non-desktop devices before admitting desktop-looking signals.
+  const isIPadDesktopMode =
+    platform === "macintel" && navigatorValue.maxTouchPoints > 1;
+  const isUnsupportedDevice =
+    userAgentData?.mobile === true ||
+    isIPadDesktopMode ||
+    /android|iphone|ipad|ipod|mobile|tablet|windows phone|iemobile|opera mini|opera mobi|webos|blackberry|bb10|kindle|silk|kaios|cros/.test(
+      userAgent,
+    );
+  if (isUnsupportedDevice) return "unknown";
+
+  if (
+    platform === "macos" ||
+    platform.startsWith("mac") ||
+    userAgent.includes("macintosh")
+  )
+    return "macos";
+  if (
+    platform === "windows" ||
+    platform.startsWith("win") ||
+    userAgent.includes("windows nt")
+  )
+    return "windows";
+  if (
+    platform === "linux" ||
+    platform.startsWith("linux") ||
+    userAgent.includes("linux")
+  )
+    return "linux";
+  return "unknown";
+}
+
+function normalizeArchitecture(
+  value: string,
+): BuzzDownloadPlatform["architecture"] {
+  const normalized = value.toLowerCase();
+  if (/arm|aarch64/.test(normalized)) return "arm64";
+  if (/x86|x64|amd64|64/.test(normalized)) return "x64";
+  return "unknown";
+}
+
+export async function detectBuzzDownloadPlatform(
+  navigatorValue: Navigator,
+): Promise<BuzzDownloadPlatform> {
+  const userAgentData = (
+    navigatorValue as Navigator & { userAgentData?: UserAgentData }
+  ).userAgentData;
+  const operatingSystem = normalizeOperatingSystem(
+    navigatorValue,
+    userAgentData,
+  );
+  let architecture = normalizeArchitecture(navigatorValue.userAgent);
+
+  if (userAgentData?.getHighEntropyValues) {
+    try {
+      const values = await userAgentData.getHighEntropyValues([
+        "architecture",
+        "bitness",
+      ]);
+      architecture = normalizeArchitecture(
+        `${values.architecture ?? ""} ${values.bitness ?? ""}`,
+      );
+    } catch {
+      // Privacy settings may reject high-entropy client hints. The matcher
+      // below applies the safest compatible fallback for the detected OS.
+    }
+  }
+
+  return { operatingSystem, architecture };
+}
+
+function assetPattern(platform: BuzzDownloadPlatform): RegExp | undefined {
+  switch (platform.operatingSystem) {
+    case "macos":
+      // Safari withholds CPU architecture and reports MacIntel on Apple
+      // Silicon. The Intel build remains compatible there through Rosetta.
+      return platform.architecture === "arm64"
+        ? /_aarch64\.dmg$/i
+        : /_x64\.dmg$/i;
+    case "windows":
+      return /_x64-setup[^/]*\.exe$/i;
+    case "linux":
+      return platform.architecture === "arm64"
+        ? undefined
+        : /_amd64\.AppImage$/i;
+    default:
+      return undefined;
+  }
+}
+
+export function selectBuzzDownloadUrl(
+  releases: GitHubRelease[],
+  platform: BuzzDownloadPlatform,
+): string | undefined {
+  const pattern = assetPattern(platform);
+  if (!pattern) return undefined;
+
+  for (const release of releases) {
+    if (release.draft || release.prerelease) continue;
+    const asset = release.assets.find(({ name }) => pattern.test(name));
+    if (asset) return asset.browser_download_url;
+  }
+  return undefined;
+}
+
+export async function resolveBuzzDownloadUrl(): Promise<string> {
+  const platform = await detectBuzzDownloadPlatform(navigator);
+  try {
+    const cached = JSON.parse(sessionStorage.getItem(CACHE_KEY) ?? "null") as {
+      expiresAt: number;
+      platform: BuzzDownloadPlatform;
+      url: string;
+    } | null;
+    if (
+      cached &&
+      cached.expiresAt > Date.now() &&
+      cached.platform.operatingSystem === platform.operatingSystem &&
+      cached.platform.architecture === platform.architecture
+    ) {
+      return cached.url;
+    }
+  } catch {
+    // Storage is only an optimization.
+  }
+
+  try {
+    const response = await fetch(BUZZ_RELEASES_API_URL, {
+      headers: { Accept: "application/vnd.github+json" },
+    });
+    if (!response.ok) return BUZZ_RELEASES_URL;
+    const url = selectBuzzDownloadUrl(
+      (await response.json()) as GitHubRelease[],
+      platform,
+    );
+    if (!url) return BUZZ_RELEASES_URL;
+    try {
+      sessionStorage.setItem(
+        CACHE_KEY,
+        JSON.stringify({
+          expiresAt: Date.now() + CACHE_TTL_MS,
+          platform,
+          url,
+        }),
+      );
+    } catch {
+      // Storage is only an optimization.
+    }
+    return url;
+  } catch {
+    return BUZZ_RELEASES_URL;
+  }
+}

web/tests/e2e/smoke.spec.ts

@@ -27,8 +27,51 @@ test("invite requires age and legal consent before opening Buzz", async ({
       }),
     });
   });
+  await page.route("https://api.github.com/**", async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      headers: { "Access-Control-Allow-Origin": "*" },
+      body: JSON.stringify([
+        { draft: false, prerelease: false, assets: [] },
+        {
+          draft: false,
+          prerelease: false,
+          assets: [
+            {
+              name: "Buzz_0.4.9_aarch64.dmg",
+              browser_download_url:
+                "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_aarch64.dmg",
+            },
+            {
+              name: "Buzz_0.4.9_x64.dmg",
+              browser_download_url:
+                "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_x64.dmg",
+            },
+            {
+              name: "Buzz_0.4.9_amd64.AppImage",
+              browser_download_url:
+                "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_amd64.AppImage",
+            },
+            {
+              name: "Buzz_0.4.9_x64-setup_alpha-unsigned.exe",
+              browser_download_url:
+                "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_x64-setup_alpha-unsigned.exe",
+            },
+          ],
+        },
+      ]),
+    });
+  });
   await page.goto("/invite/demo-code");
 
+  await expect(
+    page.getByRole("link", { name: "Download it now" }),
+  ).toHaveAttribute(
+    "href",
+    "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_x64-setup_alpha-unsigned.exe",
+  );
+
   const ageConfirmation = page.getByLabel("I am 18 years of age or older.");
   const agreementConfirmation = page.getByLabel(
     "I agree to the Buzz Terms of Service and Privacy Policy.",
@@ -73,3 +116,91 @@ test("invite requires age and legal consent before opening Buzz", async ({
   expect(consentBox?.y).toBeLessThan(acceptButtonBox?.y ?? 0);
   expect(consentBox?.width).toBe(acceptButtonBox?.width);
 });
+
+test("invite download falls back for mobile and non-desktop devices", async ({
+  browser,
+}) => {
+  const unsupportedDevices = [
+    {
+      name: "iPhone Safari",
+      platform: "iPhone",
+      userAgent:
+        "Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15",
+      maxTouchPoints: 5,
+    },
+    {
+      name: "iPadOS desktop mode",
+      platform: "MacIntel",
+      userAgent:
+        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15) AppleWebKit/605.1.15",
+      maxTouchPoints: 5,
+    },
+    {
+      name: "Android phone",
+      platform: "Linux armv8l",
+      userAgent:
+        "Mozilla/5.0 (Linux; Android 15; Pixel 9 Pro) AppleWebKit/537.36 Mobile",
+      maxTouchPoints: 5,
+    },
+    {
+      name: "ChromeOS",
+      platform: "Linux x86_64",
+      userAgent: "Mozilla/5.0 (X11; CrOS x86_64 16093.68.0) AppleWebKit/537.36",
+      maxTouchPoints: 0,
+    },
+  ];
+
+  for (const device of unsupportedDevices) {
+    const context = await browser.newContext({ userAgent: device.userAgent });
+    await context.addInitScript(({ platform, maxTouchPoints }) => {
+      Object.defineProperties(navigator, {
+        platform: { configurable: true, value: platform },
+        maxTouchPoints: { configurable: true, value: maxTouchPoints },
+        userAgentData: {
+          configurable: true,
+          value: { platform, mobile: maxTouchPoints > 0 },
+        },
+      });
+    }, device);
+    const page = await context.newPage();
+    await page.route("**/api/join-policy", async (route) => {
+      await route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({ policy: null }),
+      });
+    });
+    await page.route("https://api.github.com/**", async (route) => {
+      await route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        headers: { "Access-Control-Allow-Origin": "*" },
+        body: JSON.stringify([
+          {
+            draft: false,
+            prerelease: false,
+            assets: [
+              {
+                name: "Buzz_0.4.9_x64.dmg",
+                browser_download_url:
+                  "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_x64.dmg",
+              },
+              {
+                name: "Buzz_0.4.9_amd64.AppImage",
+                browser_download_url:
+                  "https://github.com/block/buzz/releases/download/v0.4.9/Buzz_0.4.9_amd64.AppImage",
+              },
+            ],
+          },
+        ]),
+      });
+    });
+
+    await page.goto("/invite/demo-code");
+    await expect(
+      page.getByRole("link", { name: "Download it now" }),
+      device.name,
+    ).toHaveAttribute("href", "https://github.com/block/buzz/releases");
+    await context.close();
+  }
+});