From 857a8621ec89878b3ffa2776a45eb2e9d25f3dee Mon Sep 17 00:00:00 2001
From: Bryan Van Deusen <bryan.vandeusen@fabledsword.com>
Date: Sat, 9 May 2026 20:17:17 -0400
Subject: [PATCH] feat(web): MobileNavDrawer off-canvas nav for <md viewport

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 web/src/lib/components/MobileNavDrawer.svelte | 138 ++++++++++++++++++
 .../lib/components/MobileNavDrawer.test.ts    |  43 ++++++
 2 files changed, 181 insertions(+)
 create mode 100644 web/src/lib/components/MobileNavDrawer.svelte
 create mode 100644 web/src/lib/components/MobileNavDrawer.test.ts

diff --git a/web/src/lib/components/MobileNavDrawer.svelte b/web/src/lib/components/MobileNavDrawer.svelte
new file mode 100644
index 00000000..f9f2d7c7
--- /dev/null
+++ b/web/src/lib/components/MobileNavDrawer.svelte
@@ -0,0 +1,138 @@
+<script lang="ts">
+  import { X } from 'lucide-svelte';
+  import { page } from '$app/state';
+  import { goto } from '$app/navigation';
+  import { user, logout } from '$lib/auth/store.svelte';
+  import { mobileNav, closeMobileNav } from '$lib/stores/mobileNav.svelte';
+
+  let previouslyFocused: HTMLElement | null = null;
+  let firstNavLink: HTMLAnchorElement | undefined = $state();
+
+  const navItems = [
+    { href: '/',                label: 'Home' },
+    { href: '/library/artists', label: 'Artists' },
+    { href: '/library/albums',  label: 'Albums' },
+    { href: '/library/liked',   label: 'Liked' },
+    { href: '/library/history', label: 'History' },
+    { href: '/discover',        label: 'Discover' },
+    { href: '/playlists',       label: 'Playlists' }
+  ];
+
+  function isActive(href: string): boolean {
+    if (href === '/') return page.url.pathname === '/';
+    return page.url.pathname.startsWith(href);
+  }
+
+  async function handleLogout() {
+    closeMobileNav();
+    await logout();
+    goto('/login', { replaceState: true });
+  }
+
+  function onLinkClick() {
+    closeMobileNav();
+  }
+
+  $effect(() => {
+    if (mobileNav.value) {
+      previouslyFocused = document.activeElement as HTMLElement | null;
+      Promise.resolve().then(() => firstNavLink?.focus());
+    } else if (previouslyFocused) {
+      previouslyFocused.focus();
+      previouslyFocused = null;
+    }
+  });
+
+  function onKeydown(e: KeyboardEvent) {
+    if (mobileNav.value && e.key === 'Escape') {
+      closeMobileNav();
+    }
+  }
+</script>
+
+<svelte:window onkeydown={onKeydown} />
+
+{#if mobileNav.value}
+  <button
+    type="button"
+    aria-label="Close navigation backdrop"
+    class="fixed inset-0 bg-obsidian/40 z-40 md:hidden"
+    onclick={() => closeMobileNav()}
+  ></button>
+{/if}
+
+<aside
+  aria-label="Main navigation"
+  aria-hidden={!mobileNav.value}
+  inert={!mobileNav.value}
+  class="fixed top-0 left-0 h-full w-[min(280px,80vw)] bg-surface z-50 md:hidden
+         transition-transform duration-200 flex flex-col
+         motion-reduce:transition-none
+         {mobileNav.value ? 'translate-x-0' : '-translate-x-full'}"
+>
+  <div class="flex items-center justify-between border-b border-border px-4 py-3">
+    <h2 class="text-lg font-semibold">Navigate</h2>
+    <button
+      type="button"
+      aria-label="Close navigation"
+      onclick={() => closeMobileNav()}
+      class="text-text-secondary hover:text-text-primary min-h-[44px] min-w-[44px]
+             flex items-center justify-center"
+    >
+      <X size={20} />
+    </button>
+  </div>
+
+  <nav class="flex-1 overflow-y-auto p-2">
+    <ul>
+      {#each navItems as item, i (item.href)}
+        <li>
+          <a
+            bind:this={i === 0 ? firstNavLink : undefined}
+            href={item.href}
+            onclick={onLinkClick}
+            class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
+            aria-current={isActive(item.href) ? 'page' : undefined}
+          >
+            {item.label}
+          </a>
+        </li>
+      {/each}
+    </ul>
+
+    <hr class="my-2 border-border" />
+
+    <ul>
+      <li>
+        <a
+          href="/settings"
+          onclick={onLinkClick}
+          class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
+        >
+          Settings
+        </a>
+      </li>
+      {#if user.value?.is_admin}
+        <li>
+          <a
+            href="/admin"
+            onclick={onLinkClick}
+            class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
+          >
+            Admin
+          </a>
+        </li>
+      {/if}
+      <li>
+        <button
+          type="button"
+          onclick={handleLogout}
+          class="flex w-full items-center min-h-[44px] rounded px-3 py-2 text-left
+                 hover:bg-surface-hover"
+        >
+          Log out
+        </button>
+      </li>
+    </ul>
+  </nav>
+</aside>
diff --git a/web/src/lib/components/MobileNavDrawer.test.ts b/web/src/lib/components/MobileNavDrawer.test.ts
new file mode 100644
index 00000000..c094d85b
--- /dev/null
+++ b/web/src/lib/components/MobileNavDrawer.test.ts
@@ -0,0 +1,43 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { render, screen } from '@testing-library/svelte';
+import MobileNavDrawer from './MobileNavDrawer.svelte';
+import { mobileNav, openMobileNav, closeMobileNav } from '$lib/stores/mobileNav.svelte';
+
+describe('MobileNavDrawer', () => {
+  beforeEach(() => {
+    closeMobileNav();
+  });
+
+  it('renders inert + aria-hidden when closed', () => {
+    render(MobileNavDrawer);
+    const aside = screen.getByLabelText('Main navigation');
+    expect(aside.getAttribute('aria-hidden')).toBe('true');
+    expect(aside.hasAttribute('inert')).toBe(true);
+  });
+
+  it('flips to visible when mobileNav opens', async () => {
+    render(MobileNavDrawer);
+    openMobileNav();
+    await Promise.resolve();
+    const aside = screen.getByLabelText('Main navigation');
+    expect(aside.getAttribute('aria-hidden')).toBe('false');
+    expect(aside.hasAttribute('inert')).toBe(false);
+  });
+
+  it('renders all nav items + Settings + Log out', () => {
+    openMobileNav();
+    render(MobileNavDrawer);
+    expect(screen.getByText('Home')).toBeInTheDocument();
+    expect(screen.getByText('Artists')).toBeInTheDocument();
+    expect(screen.getByText('Settings')).toBeInTheDocument();
+    expect(screen.getByText('Log out')).toBeInTheDocument();
+  });
+
+  it('Escape key closes the drawer', () => {
+    openMobileNav();
+    render(MobileNavDrawer);
+    expect(mobileNav.value).toBe(true);
+    window.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape' }));
+    expect(mobileNav.value).toBe(false);
+  });
+});