fix(desktop): link release notes from the update downloaded toast

apps/web/src/components/Sidebar.tsx

@@ -133,6 +133,7 @@ import {
   shouldShowArm64IntelBuildWarning,
   shouldToastDesktopUpdateActionResult,
 } from "./desktopUpdate.logic";
+import { showDesktopUpdateDownloadedToast } from "./desktopUpdate.toast";
 import { Alert, AlertAction, AlertDescription, AlertTitle } from "./ui/alert";
 import { Button } from "./ui/button";
 import {
@@ -3509,11 +3510,7 @@ export default function Sidebar() {
         .downloadUpdate()
         .then((result) => {
           if (result.completed) {
-            toastManager.add({
-              type: "success",
-              title: "Update downloaded",
-              description: "Restart the app from the update button to install it.",
-            });
+            showDesktopUpdateDownloadedToast(bridge, result.state);
           }
           if (!shouldToastDesktopUpdateActionResult(result)) return;
           const actionError = getDesktopUpdateActionError(result);

apps/web/src/components/desktopUpdate.logic.test.ts

@@ -7,6 +7,7 @@ import {
   getDesktopUpdateActionError,
   getDesktopUpdateButtonTooltip,
   getDesktopUpdateInstallConfirmationMessage,
+  getDesktopUpdateReleaseUrl,
   isDesktopUpdateButtonDisabled,
   resolveDesktopUpdateButtonAction,
   shouldShowArm64IntelBuildWarning,
@@ -158,6 +159,23 @@ describe("getDesktopUpdateActionError", () => {
 });
 
 describe("desktop update UI helpers", () => {
+  it("builds the stable release URL for a downloaded version", () => {
+    expect(getDesktopUpdateReleaseUrl("0.0.30")).toBe(
+      "https://github.com/pingdotgg/t3code/releases/tag/v0.0.30",
+    );
+  });
+
+  it("builds the nightly release URL without dropping its version suffix", () => {
+    expect(getDesktopUpdateReleaseUrl("0.0.30-nightly.20260728.931")).toBe(
+      "https://github.com/pingdotgg/t3code/releases/tag/v0.0.30-nightly.20260728.931",
+    );
+  });
+
+  it("omits the release URL when the updater does not report a version", () => {
+    expect(getDesktopUpdateReleaseUrl(null)).toBeNull();
+    expect(getDesktopUpdateReleaseUrl("  ")).toBeNull();
+  });
+
   it("toasts only for actionable updater errors", () => {
     expect(
       shouldToastDesktopUpdateActionResult({

apps/web/src/components/desktopUpdate.logic.ts

@@ -3,6 +3,24 @@ import { isWindowsPlatform } from "../lib/utils";
 
 export type DesktopUpdateButtonAction = "download" | "install" | "none";
 
+const DESKTOP_RELEASE_TAG_URL = "https://github.com/pingdotgg/t3code/releases/tag";
+
+/**
+ * The main process fills `downloadedVersion` from the updater's `update-downloaded`
+ * event, which is dispatched on its own fiber. A download RPC can therefore resolve
+ * before that write lands, so fall back to the version the download was started for.
+ */
+export function getDesktopUpdateDownloadedVersion(state: DesktopUpdateState): string | null {
+  return state.downloadedVersion ?? state.availableVersion;
+}
+
+/** Release notes for an exact downloaded build; nightly suffixes are part of the tag. */
+export function getDesktopUpdateReleaseUrl(version: string | null): string | null {
+  const normalizedVersion = version?.trim();
+  if (!normalizedVersion) return null;
+  return `${DESKTOP_RELEASE_TAG_URL}/v${encodeURIComponent(normalizedVersion)}`;
+}
+
 export function resolveDesktopUpdateButtonAction(
   state: DesktopUpdateState,
 ): DesktopUpdateButtonAction {

apps/web/src/components/desktopUpdate.toast.test.tsx

@@ -0,0 +1,121 @@
+import { isValidElement, type ReactElement, type ReactNode } from "react";
+import { beforeEach, describe, expect, it, vi } from "vite-plus/test";
+import type { DesktopUpdateState } from "@t3tools/contracts";
+
+const testState = vi.hoisted(() => ({
+  addToast: vi.fn(),
+}));
+
+vi.mock("./ui/toast", () => ({
+  toastManager: { add: testState.addToast },
+}));
+
+import { showDesktopUpdateDownloadedToast } from "./desktopUpdate.toast";
+
+type ClickableElement = ReactElement<{ readonly onClick?: () => void }>;
+
+/** Walks the rendered description, invoking function components, to find the link button. */
+function findReleaseNotesLink(node: ReactNode): ClickableElement | null {
+  if (Array.isArray(node)) {
+    for (const child of node) {
+      const found = findReleaseNotesLink(child);
+      if (found) return found;
+    }
+    return null;
+  }
+  if (!isValidElement(node)) return null;
+  const element = node as ReactElement<{ readonly children?: ReactNode }>;
+  if (element.type === "button") return element as ClickableElement;
+  if (typeof element.type === "function") {
+    const render = element.type as (props: unknown) => ReactNode;
+    return findReleaseNotesLink(render(element.props));
+  }
+  return findReleaseNotesLink(element.props.children);
+}
+
+function getDescription(): ReactNode {
+  const toast = testState.addToast.mock.calls[0]?.[0] as { description?: ReactNode } | undefined;
+  return toast?.description ?? null;
+}
+
+function downloadedState(overrides: Partial<DesktopUpdateState> = {}): DesktopUpdateState {
+  return {
+    enabled: true,
+    status: "downloaded",
+    channel: "latest",
+    currentVersion: "0.0.29",
+    hostArch: "arm64",
+    appArch: "arm64",
+    runningUnderArm64Translation: false,
+    availableVersion: "0.0.30",
+    downloadedVersion: "0.0.30",
+    releaseNotes: [],
+    downloadPercent: 100,
+    checkedAt: null,
+    message: null,
+    errorContext: null,
+    canRetry: true,
+    ...overrides,
+  };
+}
+
+describe("showDesktopUpdateDownloadedToast", () => {
+  beforeEach(() => {
+    testState.addToast.mockReset();
+  });
+
+  it("opens the downloaded version's release notes", async () => {
+    const openExternal = vi.fn().mockResolvedValue(true);
+
+    showDesktopUpdateDownloadedToast({ openExternal }, downloadedState());
+    const link = findReleaseNotesLink(getDescription());
+    link?.props.onClick?.();
+    await vi.waitFor(() => {
+      expect(openExternal).toHaveBeenCalledWith(
+        "https://github.com/pingdotgg/t3code/releases/tag/v0.0.30",
+      );
+    });
+    expect(testState.addToast).toHaveBeenCalledTimes(1);
+  });
+
+  it("falls back to the version the download was started for", async () => {
+    const openExternal = vi.fn().mockResolvedValue(true);
+
+    // The `update-downloaded` event can land after the download RPC resolves.
+    showDesktopUpdateDownloadedToast(
+      { openExternal },
+      downloadedState({ downloadedVersion: null }),
+    );
+    findReleaseNotesLink(getDescription())?.props.onClick?.();
+
+    await vi.waitFor(() => {
+      expect(openExternal).toHaveBeenCalledWith(
+        "https://github.com/pingdotgg/t3code/releases/tag/v0.0.30",
+      );
+    });
+  });
+
+  it("omits the link when the updater reports no version at all", () => {
+    showDesktopUpdateDownloadedToast(
+      { openExternal: vi.fn() },
+      downloadedState({ availableVersion: null, downloadedVersion: null }),
+    );
+
+    expect(findReleaseNotesLink(getDescription())).toBeNull();
+  });
+
+  it.each([
+    ["returns false", vi.fn().mockResolvedValue(false)],
+    ["rejects", vi.fn().mockRejectedValue(new Error("open failed"))],
+  ])("shows an error when opening release notes %s", async (_description, openExternal) => {
+    showDesktopUpdateDownloadedToast({ openExternal }, downloadedState());
+    findReleaseNotesLink(getDescription())?.props.onClick?.();
+
+    await vi.waitFor(() => {
+      expect(testState.addToast).toHaveBeenLastCalledWith({
+        type: "error",
+        title: "Unable to open release notes",
+      });
+    });
+  });
+});

apps/web/src/components/desktopUpdate.toast.tsx

@@ -0,0 +1,55 @@
+import type { DesktopBridge, DesktopUpdateState } from "@t3tools/contracts";
+import { ArrowRightIcon } from "lucide-react";
+
+import {
+  getDesktopUpdateDownloadedVersion,
+  getDesktopUpdateReleaseUrl,
+} from "./desktopUpdate.logic";
+import { toastManager } from "./ui/toast";
+
+type DesktopUpdateShell = Pick<DesktopBridge, "openExternal">;
+
+function ReleaseNotesLink({
+  shell,
+  releaseUrl,
+}: {
+  shell: DesktopUpdateShell;
+  releaseUrl: string;
+}) {
+  return (
+    <button
+      className="ml-2 inline-flex cursor-pointer items-center gap-1 align-baseline text-muted-foreground underline decoration-dotted underline-offset-4 transition-colors hover:text-foreground"
+      onClick={() => {
+        void (async () => {
+          try {
+            if (await shell.openExternal(releaseUrl)) return;
+          } catch {
+            // Surface rejected IPC calls through the same user-visible fallback.
+          }
+          toastManager.add({ type: "error", title: "Unable to open release notes" });
+        })();
+      }}
+      type="button"
+    >
+      Read more
+      <ArrowRightIcon aria-hidden className="size-3 -rotate-45" strokeWidth={2.25} />
+    </button>
+  );
+}
+
+export function showDesktopUpdateDownloadedToast(
+  shell: DesktopUpdateShell,
+  state: DesktopUpdateState,
+): void {
+  const releaseUrl = getDesktopUpdateReleaseUrl(getDesktopUpdateDownloadedVersion(state));
+  toastManager.add({
+    type: "success",
+    title: "Update downloaded",
+    description: (
+      <>
+        Restart the app from the update button to install it.
+        {releaseUrl ? <ReleaseNotesLink releaseUrl={releaseUrl} shell={shell} /> : null}
+      </>
+    ),
+  });
+}

apps/web/src/components/sidebar/SidebarUpdatePill.tsx

@@ -14,6 +14,7 @@ import {
   shouldShowDesktopUpdateButton,
   shouldToastDesktopUpdateActionResult,
 } from "../desktopUpdate.logic";
+import { showDesktopUpdateDownloadedToast } from "../desktopUpdate.toast";
 import { Alert, AlertDescription, AlertTitle } from "../ui/alert";
 import { Separator } from "../ui/separator";
 import { Tooltip, TooltipPopup, TooltipTrigger } from "../ui/tooltip";
@@ -80,11 +81,7 @@ export function SidebarUpdatePill() {
         .downloadUpdate()
         .then((result) => {
           if (result.completed) {
-            toastManager.add({
-              type: "success",
-              title: "Update downloaded",
-              description: "Restart the app from the update button to install it.",
-            });
+            showDesktopUpdateDownloadedToast(bridge, result.state);
           }
           if (!shouldToastDesktopUpdateActionResult(result)) return;
           const actionError = getDesktopUpdateActionError(result);