feat: show unread count badge on favicon

Closes #560. Composes the active inbox's unread count over the base favicon as an SVG badge, served as a percent-encoded data: URL, so new mail is visible on a tab that is not focused — including when the browser collapses tabs to icon-only, where a title-based count disappears entirely. The base icon is read from the rendered <link rel="icon"> rather than from config, so admin and per-domain branding overrides are inherited for free: the count is drawn on whatever logo the deployment actually serves. Keeping the badge in SVG rather than rasterising to a canvas also means the browser can rasterise it at whatever size it asks for, so a HiDPI tab is not served a 16px bitmap. Notes on the approach: - The badge link is an *additional* icon link that we append and mark as ours; we never remove or mutate a link we did not create. Next's metadata icons are rendered by React, which keeps a fiber pointing at that DOM node, so removing it would leave React holding a detached node and throw "Cannot read properties of null (reading 'removeChild')" on the next commit that deletes the fiber. Appending instead means the last-declared icon wins, and non-SVG fallback links survive with their type/sizes intact. (The usual recipe for this feature — assign canvas.toDataURL() to the existing link's href — does both of the things that break here.) - Every change of state is an *insertion* of a fresh link of ours, never a mutation or a removal, because that is the only signal a browser reliably re-reads the favicon on. Firefox ignores an in-place href change, and it equally ignores a removal — so clearing the badge by deleting our link left a stale count painted on the tab until a hard reload. Clearing it instead inserts a new link of ours carrying the original base href. - Holding last place has to be defended: on a client-side navigation React re-hoists its metadata icon link into <head>, landing after ours, and the base icon silently wins again. A MutationObserver on <head> moves our own link back to the end whenever a foreign icon link appears — moving only our node, never anyone else's. It no-ops once ours is last again, so a move cannot feed itself. - The badge is a full-width band across the foot of the icon, drawn to the metrics measured from Gmail's own 16px favicon: band height 0.625 of the icon, digit cap height 0.44, flush to the edges, corners rounded by about a pixel. Full width is what keeps a three-glyph label legible — rounded ends waste exactly the horizontal space it needs. Neutral white with black digits rather than the conventional red: faviconUrl is admin-overridable and Bulwark's own icon is rgb(219,45,84), so a red badge sat red-on-red. - The base SVG may be admin-uploaded, and the branding route deliberately serves it under a sandboxing CSP because SVG can carry script. Re-emitting it as a same-origin data: URL would un-fence that, so script, foreignObject and every on* handler are stripped before serialising. - Mounted in the root layout, not on the mail route: the badge belongs to the tab, so mounting it on the page would clear it on every hop to settings, calendar or contacts.
2026-07-16 18:00:41 +02:00
parent 578339c400
commit 334fdbfb86
32 changed files with 1598 additions and 1 deletions
@@ -0,0 +1,98 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { render } from '@testing-library/react';
+import { FaviconBadge } from '@/components/favicon-badge';
+import { useFaviconBadge } from '@/hooks/use-favicon-badge';
+import { useEmailStore } from '@/stores/email-store';
+import { useSettingsStore } from '@/stores/settings-store';
+import type { Mailbox } from '@/lib/jmap/types';
+
+vi.mock('@/hooks/use-favicon-badge', () => ({
+  useFaviconBadge: vi.fn(),
+}));
+
+const useFaviconBadgeMock = vi.mocked(useFaviconBadge);
+
+function mailbox(patch: Partial<Mailbox> & { id: string }): Mailbox {
+  return {
+    name: patch.id,
+    sortOrder: 0,
+    totalEmails: 0,
+    unreadEmails: 0,
+    totalThreads: 0,
+    unreadThreads: 0,
+    isSubscribed: true,
+    myRights: {
+      mayReadItems: true,
+      mayAddItems: true,
+      mayRemoveItems: true,
+      maySetSeen: true,
+      maySetKeywords: true,
+      mayCreateChild: true,
+      mayRename: true,
+      mayDelete: true,
+      maySubmit: true,
+    },
+    ...patch,
+  } as Mailbox;
+}
+
+const initialMailboxes = useEmailStore.getState().mailboxes;
+
+beforeEach(() => {
+  useEmailStore.setState({ mailboxes: initialMailboxes });
+  useSettingsStore.setState({ faviconUnreadBadge: true });
+});
+
+afterEach(() => {
+  useEmailStore.setState({ mailboxes: initialMailboxes });
+  useSettingsStore.setState({ faviconUnreadBadge: true });
+  vi.clearAllMocks();
+});
+
+describe('FaviconBadge', () => {
+  it('badges the unread count of the primary inbox', () => {
+    useEmailStore.setState({
+      mailboxes: [mailbox({ id: 'inbox', role: 'inbox', unreadEmails: 7 })],
+    });
+
+    const { container } = render(<FaviconBadge />);
+
+    expect(useFaviconBadgeMock).toHaveBeenCalledWith(7, true);
+    expect(container.firstChild).toBeNull(); // renders no markup
+  });
+
+  it('disables the badge when the setting is off', () => {
+    useSettingsStore.setState({ faviconUnreadBadge: false });
+    useEmailStore.setState({
+      mailboxes: [mailbox({ id: 'inbox', role: 'inbox', unreadEmails: 7 })],
+    });
+
+    render(<FaviconBadge />);
+
+    expect(useFaviconBadgeMock).toHaveBeenCalledWith(7, false);
+  });
+
+  it('ignores a shared inbox, even when it sorts first', () => {
+    // Shared and group inboxes ship in the same `mailboxes` array. A plain
+    // `role === 'inbox'` lookup would badge somebody else's inbox on a
+    // delegated setup, so the store's canonical `!isShared` filter is required.
+    useEmailStore.setState({
+      mailboxes: [
+        mailbox({ id: 'shared', role: 'inbox', isShared: true, unreadEmails: 99 }),
+        mailbox({ id: 'mine', role: 'inbox', unreadEmails: 4 }),
+      ],
+    });
+
+    render(<FaviconBadge />);
+
+    expect(useFaviconBadgeMock).toHaveBeenCalledWith(4, true);
+  });
+
+  it('badges zero when there is no inbox yet', () => {
+    useEmailStore.setState({ mailboxes: [] });
+
+    render(<FaviconBadge />);
+
+    expect(useFaviconBadgeMock).toHaveBeenCalledWith(0, true);
+  });
+});