test: add UsernameComponentTest

tests/Filament/UsernameComponentTest.php

@@ -0,0 +1,31 @@
+<?php
+
+use App\Livewire\UsernameComponent;
+use App\Models\User;
+
+use function Pest\Livewire\livewire;
+
+beforeEach(function () {
+    $this->user = User::factory()->create();
+
+    $this->actingAs($this->user);
+});
+
+it('can render component', function () {
+    livewire(UsernameComponent::class)
+        ->assertStatus(200);
+});
+
+it('loads initial data', function () {
+    livewire(UsernameComponent::class)
+        ->assertViewHas('data.username', $this->user->username);
+});
+
+it('updates the username', function () {
+    livewire(UsernameComponent::class)
+        ->set('data.username', 'new-username')
+        ->call('submit');
+
+    expect($this->user->refresh())
+        ->username->toBe('new-username');
+});