Add M3 error pages and the Markdown mail theme

Error pages for 401 to 503 in an error-view root appended to view.paths,
with an inline fallback when the Vite build is missing, and a mail theme
rendered from the application's scheme JSON, with opt-in header and
message components. Completes Phase 9.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy

tests/Feature/ErrorPagesTest.php

@@ -0,0 +1,183 @@
+<?php
+
+use Illuminate\Foundation\Exceptions\RegisterErrorViewPaths;
+use Illuminate\Support\Facades\File;
+use Illuminate\Support\Facades\Route;
+use Illuminate\Support\Facades\Vite;
+use Illuminate\Support\Str;
+use NoNameWeb\LivewireMaterial\LivewireMaterialServiceProvider;
+
+beforeEach(function () {
+    $this->temporary = sys_get_temp_dir().'/livewire-material-errors-'.Str::random(8);
+    File::ensureDirectoryExists($this->temporary);
+
+    Route::middleware('web')->get('/abort/{code}', fn (string $code) => abort((int) $code, request()->query('message', '')));
+});
+
+afterEach(function () {
+    File::deleteDirectory($this->temporary);
+});
+
+/**
+ * Testbench's skeleton application ships an errors/503.blade.php of its own — an application
+ * view, which rightly wins over the package's. A test of the package's 503 stands in an
+ * application without one.
+ */
+function withoutSkeletonErrorViews(): void
+{
+    $views = test()->temporary.'/views';
+
+    File::ensureDirectoryExists($views);
+
+    config(['view.paths' => [$views, LivewireMaterialServiceProvider::errorViewPath()]]);
+}
+
+it('renders the package page for each status', function (int $code, string $headline, string $sentence) {
+    withoutSkeletonErrorViews();
+
+    $this->withoutVite()
+        ->get("/abort/{$code}")
+        ->assertStatus($code)
+        ->assertSee('data-error-page', false)
+        ->assertSee("{$code}</p>", false)
+        ->assertSee($headline)
+        ->assertSee($sentence);
+})->with([
+    [403, 'You don’t have access', 'Your account isn’t allowed to open this page.'],
+    [404, 'Page not found', 'The page you’re looking for doesn’t exist or has moved.'],
+    [419, 'This page has expired', 'Refresh the page'],
+    [429, 'Slow down a little', 'Wait a moment, then try again.'],
+    [500, 'Something went wrong', 'An error on our side'],
+    [503, 'We’ll be right back', 'We’re making some improvements.'],
+]);
+
+it('draws the framework\'s own error pages in the package layout', function () {
+    $this->withoutVite()
+        ->get('/abort/401')
+        ->assertStatus(401)
+        ->assertSee('data-error-page', false)
+        ->assertSee('Unauthorized')
+        ->assertSee('Go home');
+});
+
+it('appends the error-view root to view.paths after the application\'s, before the view finder is built', function () {
+    $root = LivewireMaterialServiceProvider::errorViewPath();
+
+    expect(realpath($root))->toBe(realpath(__DIR__.'/../../resources/views/error-pages'))
+        ->and(File::directories($root))->toBe([$root.'/errors'])
+        ->and(config('view.paths'))->toBe([resource_path('views'), $root])
+        ->and(app()->viewPath())->toBe(resource_path('views'))
+        ->and(app('view')->getFinder()->getPaths())->toContain($root);
+
+    $provider = app()->getProvider(LivewireMaterialServiceProvider::class);
+    (fn () => $this->registerErrorViews())->call($provider);
+
+    expect(config('view.paths'))->toBe([resource_path('views'), $root]);
+});
+
+it('lets the application\'s own error view win', function () {
+    File::ensureDirectoryExists($this->temporary.'/errors');
+    File::put($this->temporary.'/errors/404.blade.php', 'The application view');
+
+    config(['view.paths' => [$this->temporary, ...config('view.paths')]]);
+
+    $this->withoutVite()
+        ->get('/abort/404')
+        ->assertNotFound()
+        ->assertSee('The application view')
+        ->assertDontSee('data-error-page', false);
+
+    $this->get('/abort/403')->assertSee('data-error-page', false);
+});
+
+it('loads the application\'s Vite entries', function () {
+    File::ensureDirectoryExists($this->temporary.'/build');
+    File::put($this->temporary.'/build/manifest.json', json_encode([
+        'workbench/resources/css/app.css' => ['file' => 'assets/app-probe.css', 'src' => 'workbench/resources/css/app.css', 'isEntry' => true],
+        'workbench/resources/js/app.js' => ['file' => 'assets/app-probe.js', 'src' => 'workbench/resources/js/app.js', 'isEntry' => true],
+    ]));
+
+    app()->usePublicPath($this->temporary);
+    Vite::useHotFile($this->temporary.'/hot');
+
+    $this->get('/abort/404')
+        ->assertNotFound()
+        ->assertSee('build/assets/app-probe.css', false)
+        ->assertSee('build/assets/app-probe.js', false)
+        ->assertDontSee('data-error-fallback', false);
+});
+
+it('still renders, in the application\'s scheme, when the Vite manifest is missing', function () {
+    File::put($this->temporary.'/material-scheme.json', json_encode([
+        'light' => ['surface' => '#fafaf0', 'primary' => '#123456'],
+        'dark' => ['surface' => '#101010'],
+    ]));
+
+    config(['livewire-material.scheme' => $this->temporary.'/material-scheme.json']);
+    app()->usePublicPath($this->temporary);
+    Vite::useHotFile($this->temporary.'/hot');
+
+    $this->get('/abort/500')
+        ->assertStatus(500)
+        ->assertSee('Something went wrong')
+        ->assertSee('<style data-error-fallback>', false)
+        ->assertSee('--md-sys-color-surface: #fafaf0;', false)
+        ->assertSee('--md-sys-color-primary: #123456;', false)
+        ->assertSee('--md-sys-color-surface: #101010;', false)
+        ->assertSee('--md-sys-color-on-surface: #34313a;', false)
+        ->assertDontSee('/build/', false);
+});
+
+it('shows the message an application passed for 403 and 503', function (int $code, string $message) {
+    withoutSkeletonErrorViews();
+
+    $this->withoutVite()
+        ->get("/abort/{$code}?message=".urlencode($message))
+        ->assertStatus($code)
+        ->assertSee($message);
+})->with([
+    [403, 'Only the owner can open this share.'],
+    [503, 'Back at 14:00 after the upgrade.'],
+]);
+
+it('does not take maintenance mode\'s "Service Unavailable" for a message', function () {
+    withoutSkeletonErrorViews();
+
+    $this->withoutVite()
+        ->get('/abort/503?message=Service+Unavailable')
+        ->assertStatus(503)
+        ->assertSee('We’re making some improvements.')
+        ->assertDontSee('>Service Unavailable<', false);
+});
+
+it('prerenders the 503 page for maintenance mode, without an exception', function () {
+    withoutSkeletonErrorViews();
+    $this->withoutVite();
+
+    (new RegisterErrorViewPaths)();
+
+    expect(view('errors::503', ['retryAfter' => 60])->render())
+        ->toContain('data-error-page')
+        ->toContain('We’ll be right back')
+        ->toContain('location.reload()');
+});
+
+it('offers Back only when the visitor came from another page', function () {
+    $this->withoutVite()
+        ->get('/abort/404')
+        ->assertSee('Go home')
+        ->assertDontSee('Go back');
+
+    $this->withoutVite()
+        ->get('/abort/404', ['Referer' => url('/shares')])
+        ->assertSee('Go back')
+        ->assertSee('href="'.url('/shares').'"', false);
+});
+
+it('sends an expired form back to its page to refresh', function () {
+    $this->withoutVite()
+        ->get('/abort/419', ['Referer' => url('/settings')])
+        ->assertStatus(419)
+        ->assertSee('href="'.url('/settings').'"', false)
+        ->assertSee('Refresh the page');
+});