adding a cart

tests/Feature/Models/CartTest.php

@@ -0,0 +1,38 @@
+<?php
+
+use App\Models\Cart;
+use App\Models\Product;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+
+uses(RefreshDatabase::class);
+
+test('a cart belongs to a user when one is set', function () {
+    $user = User::factory()->create();
+    $cart = Cart::factory()->create(['user_id' => $user->id]);
+
+    expect($cart->user->id)->toBe($user->id);
+});
+
+test('a cart can exist without a user', function () {
+    $cart = Cart::factory()->create(['user_id' => null]);
+
+    expect($cart->user)->toBeNull();
+});
+
+test('a user has one cart', function () {
+    $user = User::factory()->create();
+    Cart::factory()->create(['user_id' => $user->id]);
+
+    expect($user->cart)->toBeInstanceOf(Cart::class);
+});
+
+test('a cart can have products with quantities', function () {
+    $cart = Cart::factory()->create(['user_id' => null]);
+    $product = Product::factory()->create();
+
+    $cart->products()->attach($product->id, ['quantity' => 3]);
+
+    expect($cart->products)->toHaveCount(1);
+    expect($cart->products->first()->pivot->quantity)->toBe(3);
+});