Extract marketing download logic into shared helpers

apps/marketing/package.json

@@ -7,13 +7,15 @@
     "dev": "astro dev",
     "build": "astro build",
     "preview": "astro preview",
-    "typecheck": "astro sync && astro check"
+    "typecheck": "astro sync && astro check",
+    "test": "vitest run"
   },
   "dependencies": {
     "astro": "^6.0.4"
   },
   "devDependencies": {
     "@astrojs/check": "^0.9.7",
-    "typescript": "catalog:"
+    "typescript": "catalog:",
+    "vitest": "catalog:"
   }
 }

apps/marketing/src/lib/download.test.ts

@@ -0,0 +1,123 @@
+import { describe, expect, it } from "vitest";
+import { detectPlatform, pickAsset } from "./download";
+import type { ReleaseAsset } from "./releases";
+
+/* -------------------------------------------------------------------------- */
+/*  Fixture helpers                                                           */
+/* -------------------------------------------------------------------------- */
+
+function asset(name: string, url = `https://example.com/${name}`): ReleaseAsset {
+  return { name, browser_download_url: url };
+}
+
+const SAMPLE_ASSETS: ReleaseAsset[] = [
+  asset("okcode-1.0.0-arm64.dmg"),
+  asset("okcode-1.0.0-x64.dmg"),
+  asset("okcode-1.0.0-x64.exe"),
+  asset("okcode-1.0.0-x64.AppImage"),
+];
+
+/* -------------------------------------------------------------------------- */
+/*  detectPlatform                                                            */
+/* -------------------------------------------------------------------------- */
+
+describe("detectPlatform", () => {
+  it("returns Windows platform for a Windows user-agent", () => {
+    const result = detectPlatform("Mozilla/5.0 (Windows NT 10.0; Win64; x64)");
+    expect(result).toEqual({ os: "win", label: "Download for Windows" });
+  });
+
+  it("returns macOS platform for a macOS user-agent", () => {
+    const result = detectPlatform("Mozilla/5.0 (Macintosh; Intel Mac OS X 14_0)");
+    expect(result).toEqual({ os: "mac", label: "Download for macOS", arch: "arm64" });
+  });
+
+  it("returns Linux platform for a Linux user-agent", () => {
+    const result = detectPlatform("Mozilla/5.0 (X11; Linux x86_64)");
+    expect(result).toEqual({ os: "linux", label: "Download for Linux" });
+  });
+
+  it("returns null for an unrecognised user-agent", () => {
+    expect(detectPlatform("")).toBeNull();
+    expect(detectPlatform("SomeBot/1.0")).toBeNull();
+  });
+
+  it("is case-insensitive", () => {
+    expect(detectPlatform("windows")).not.toBeNull();
+    expect(detectPlatform("LINUX")).not.toBeNull();
+    expect(detectPlatform("mac")).not.toBeNull();
+  });
+});
+
+/* -------------------------------------------------------------------------- */
+/*  pickAsset                                                                 */
+/* -------------------------------------------------------------------------- */
+
+describe("pickAsset", () => {
+  describe("Windows", () => {
+    const platform = { os: "win", label: "Download for Windows" };
+
+    it("selects the .exe asset", () => {
+      expect(pickAsset(SAMPLE_ASSETS, platform)).toBe("https://example.com/okcode-1.0.0-x64.exe");
+    });
+
+    it("returns null when no .exe is available", () => {
+      const assets = [asset("okcode-1.0.0-arm64.dmg")];
+      expect(pickAsset(assets, platform)).toBeNull();
+    });
+  });
+
+  describe("macOS", () => {
+    it("prefers the arch-specific .dmg", () => {
+      const platform = { os: "mac", label: "Download for macOS", arch: "arm64" };
+      expect(pickAsset(SAMPLE_ASSETS, platform)).toBe("https://example.com/okcode-1.0.0-arm64.dmg");
+    });
+
+    it("falls back to any .dmg when arch-specific is missing", () => {
+      const platform = { os: "mac", label: "Download for macOS", arch: "arm64" };
+      const assets = [asset("okcode-1.0.0.dmg")];
+      expect(pickAsset(assets, platform)).toBe("https://example.com/okcode-1.0.0.dmg");
+    });
+
+    it("selects x64 .dmg when arch is x64", () => {
+      const platform = { os: "mac", label: "Download for macOS", arch: "x64" };
+      expect(pickAsset(SAMPLE_ASSETS, platform)).toBe("https://example.com/okcode-1.0.0-x64.dmg");
+    });
+
+    it("returns null when no .dmg is available", () => {
+      const platform = { os: "mac", label: "Download for macOS", arch: "arm64" };
+      const assets = [asset("okcode-1.0.0-x64.exe")];
+      expect(pickAsset(assets, platform)).toBeNull();
+    });
+  });
+
+  describe("Linux", () => {
+    const platform = { os: "linux", label: "Download for Linux" };
+
+    it("selects the .AppImage asset", () => {
+      expect(pickAsset(SAMPLE_ASSETS, platform)).toBe(
+        "https://example.com/okcode-1.0.0-x64.AppImage",
+      );
+    });
+
+    it("returns null when no .AppImage is available", () => {
+      const assets = [asset("okcode-1.0.0-arm64.dmg")];
+      expect(pickAsset(assets, platform)).toBeNull();
+    });
+  });
+
+  describe("unknown platform", () => {
+    it("returns null for an unrecognised OS", () => {
+      const platform = { os: "freebsd", label: "Download" };
+      expect(pickAsset(SAMPLE_ASSETS, platform)).toBeNull();
+    });
+  });
+
+  describe("empty assets", () => {
+    it("returns null when assets array is empty", () => {
+      expect(pickAsset([], { os: "win", label: "Download for Windows" })).toBeNull();
+      expect(pickAsset([], { os: "mac", label: "Download for macOS", arch: "arm64" })).toBeNull();
+      expect(pickAsset([], { os: "linux", label: "Download for Linux" })).toBeNull();
+    });
+  });
+});

apps/marketing/src/lib/download.ts

@@ -0,0 +1,35 @@
+import type { ReleaseAsset } from "./releases";
+
+export interface Platform {
+  os: string;
+  label: string;
+  arch?: string;
+}
+
+export function detectPlatform(userAgent: string): Platform | null {
+  if (/Win/i.test(userAgent)) return { os: "win", label: "Download for Windows" };
+  if (/Mac/i.test(userAgent)) {
+    return {
+      os: "mac",
+      label: "Download for macOS",
+      arch: "arm64",
+    };
+  }
+  if (/Linux/i.test(userAgent)) return { os: "linux", label: "Download for Linux" };
+  return null;
+}
+
+export function pickAsset(assets: ReleaseAsset[], platform: Platform): string | null {
+  if (platform.os === "win") {
+    return assets.find((a) => a.name.endsWith("-x64.exe"))?.browser_download_url ?? null;
+  }
+  if (platform.os === "mac") {
+    const preferred = assets.find((a) => a.name.endsWith(`-${platform.arch}.dmg`));
+    const fallback = assets.find((a) => a.name.endsWith(".dmg"));
+    return (preferred ?? fallback)?.browser_download_url ?? null;
+  }
+  if (platform.os === "linux") {
+    return assets.find((a) => a.name.endsWith(".AppImage"))?.browser_download_url ?? null;
+  }
+  return null;
+}

apps/marketing/src/pages/index.astro

@@ -395,42 +395,14 @@ const themeIdeas = [
 
 <script>
   import { fetchLatestRelease, RELEASES_URL } from "../lib/releases";
-
-  function detectPlatform() {
-    const ua = navigator.userAgent;
-    if (/Win/i.test(ua)) return { os: "win", label: "Download for Windows" };
-    if (/Mac/i.test(ua)) {
-      return {
-        os: "mac",
-        label: "Download for macOS",
-        arch: "arm64",
-      };
-    }
-    if (/Linux/i.test(ua)) return { os: "linux", label: "Download for Linux" };
-    return null;
-  }
-
-  function pickAsset(assets: {name: string; browser_download_url: string}[], platform: {os: string; label: string; arch?: string}) {
-    if (platform.os === "win") {
-      return assets.find((a) => a.name.endsWith("-x64.exe"))?.browser_download_url ?? null;
-    }
-    if (platform.os === "mac") {
-      const preferred = assets.find((a) => a.name.endsWith(`-${platform.arch}.dmg`));
-      const fallback = assets.find((a) => a.name.endsWith(".dmg"));
-      return (preferred ?? fallback)?.browser_download_url ?? null;
-    }
-    if (platform.os === "linux") {
-      return assets.find((a) => a.name.endsWith(".AppImage"))?.browser_download_url ?? null;
-    }
-    return null;
-  }
+  import { detectPlatform, pickAsset } from "../lib/download";
 
   function initDownloadButton() {
     const btn = document.getElementById("download-btn") as HTMLAnchorElement | null;
     const label = document.getElementById("download-label");
     if (!btn || !label) return;
 
-    const platform = detectPlatform();
+    const platform = detectPlatform(navigator.userAgent);
     if (!platform) return;
 
     document.documentElement.dataset.platform = platform.os;
@@ -454,8 +426,8 @@ const themeIdeas = [
     const groups = document.querySelectorAll("[data-tab-group]");
     groups.forEach((group) => {
       const defaultTab = group.getAttribute("data-tab-default");
-      const buttons = Array.from(group.querySelectorAll("[data-tab-button]"));
-      const panels = Array.from(group.querySelectorAll("[data-tab-panel]"));
+      const buttons = Array.from(group.querySelectorAll<HTMLElement>("[data-tab-button]"));
+      const panels = Array.from(group.querySelectorAll<HTMLElement>("[data-tab-panel]"));
       const heroOverlay = group.querySelector("[data-hero-overlay]");
 
       const activate = (id: string) => {