feat: Cart management (#19)

Closes #7

app/Http/Controllers/CartController.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Illuminate\Support\Facades\Auth;
+
+class CartController extends Controller {
+
+    /**
+     * Add a product in given amount to cart.
+     *
+     * @param Request $request
+     * @return Response
+     */
+    public function add(Request $request): Response {
+        $args = $request->validate([
+            "product" => ["required", "exists:products,id"],
+            "amount" => ["required", "numeric", "gt:0"]
+        ]);
+
+        Auth::user()->addCartItem($args["product"], $args["amount"]);
+
+        return response(status: 200);
+    }
+
+    /**
+     * Set product amount in cart.
+     *
+     * @param Request $request
+     * @return Response
+     */
+    public function set(Request $request): Response {
+        $args = $request->validate([
+            "product" => ["required", "exists:products,id"],
+            "amount" => ["required", "numeric", "gt:0"]
+        ]);
+
+        Auth::user()->setCartItem($args["product"], $args["amount"]);
+
+        return response(status: 200);
+    }
+
+    /**
+     * Remove product from cart.
+     *
+     * @param Request $request
+     * @return Response
+     */
+    public function remove(Request $request): Response {
+        $args = $request->validate([
+            "product" => ["required", "exists:products,id", ]
+        ]);
+
+        Auth::user()->removeCartItem($args["product"]);
+
+        return response(status: 200);
+    }
+}

app/Models/User.php

@@ -7,6 +7,7 @@
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;
+use Illuminate\Support\Facades\DB;
 use Laravel\Sanctum\HasApiTokens;
 
 class User extends Authenticatable
@@ -51,6 +52,71 @@ public function cart(): BelongsToMany {
             ->withPivot(["amount"]);
     }
 
+    /**
+     * Get items in this user's cart.
+     *
+     * @return array the products added to cart with their amount
+     */
+    public function getCartItems(): array {
+        return $this->cart()->getResults()->all();
+    }
+
+    /**
+     * Get quantity of given product in cart.
+     *
+     * @param Product|int $product the product type
+     * @return int the amount of `$product` in this user's cart
+     */
+    public function getAmount(Product|int $product): int {
+        $result = $this->cart()->find($product);
+        return $result ? $result->pivot->amount : 0;
+    }
+
+    /**
+     * Add a product in given quantity to cart.
+     *
+     * @param Product|int $product the product type to add
+     * @param int $amount the amount of the given product to add
+     * @return void
+     */
+    public function addCartItem(Product|int $product, int $amount): void {
+        $validAmount = max($amount, 0);
+        $existing = $this->cart()->find($product);
+        if($existing == null) $this->cart()->attach($product, ["amount" => $validAmount]);
+        else {
+            $existing->pivot->update(["amount" => DB::raw("amount+".$validAmount)]);
+        }
+    }
+
+    /**
+     * Set a product in given quantity in this user's cart.
+     *
+     * @param Product|int $product the product type to set
+     * @param int $amount the amount of the given product to set
+     * @return void
+     */
+    public function setCartItem(Product|int $product, int $amount): void {
+        $validAmount = max($amount, 0);
+        $existing = $this->cart()->find($product);
+        if($existing == null) $this->cart()->attach($product, ["amount" => $validAmount]);
+        else {
+            $existing->pivot->update(["amount" => $validAmount]);
+        }
+    }
+
+    /**
+     * Remove a product from this user's cart, no matter how much is present.
+     *
+     * @param Product|int $product the product type to remove
+     * @return void
+     */
+    public function removeCartItem(Product|int $product): void {
+        $this->cart()->detach($product);
+    }
+
+    /**
+     * The "login" column used for authentication.
+     */
     public function username() {
         return "name";
     }

routes/web.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Http\Controllers\AuthController;
+use App\Http\Controllers\CartController;
 use Illuminate\Support\Facades\Route;
 use Illuminate\Support\Facades\Auth;
 
@@ -22,3 +23,7 @@
 Route::post("/auth/login", [AuthController::class, "login"]);
 Route::post("/auth/logout", [AuthController::class, "logout"]);
 Route::post("/auth/register", [AuthController::class, "register"]);
+
+Route::post("/cart/add", [CartController::class, "add"]);
+Route::post("/cart/set", [CartController::class, "set"]);
+Route::post("/cart/remove", [CartController::class, "remove"]);

tests/Feature/CartTest.php

@@ -0,0 +1,152 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Product;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Foundation\Testing\WithFaker;
+use Illuminate\Support\Facades\Auth;
+use Tests\TestCase;
+
+class CartTest extends TestCase {
+    use RefreshDatabase;
+
+    /**
+     * Return errors when sent data are either missing or invalid.
+     */
+    public function test_add_invalid_data(): void {
+        $user = User::factory()->create();
+
+        Auth::login($user);
+
+        $missingData = $this->postJson("/cart/add");
+        $missingData->assertInvalid(["product", "amount"]);
+
+        $invalidData = $this->postJson(
+            "/cart/add",
+            [
+                "product" => 1,
+                "amount" => -5
+            ]
+        );
+
+        $invalidData->assertInvalid(["product", "amount"]);
+    }
+
+    /**
+     * Successfully add item when valid arguments are given.
+     */
+    public function test_add_successful() {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        Auth::login($user);
+
+        $response = $this->postJson(
+            "/cart/add",
+            [
+                "product" => $product->id,
+                "amount" => 5
+            ]
+        );
+
+        $response->assertSuccessful();
+        $this->assertEquals(5, $user->cart()->find($product)->pivot->amount);
+
+        $response = $this->postJson(
+            "/cart/add",
+            [
+                "product" => $product->id,
+                "amount" => 5
+            ]
+        );
+
+        $response->assertSuccessful();
+        $this->assertEquals(10, $user->cart()->find($product)->pivot->amount);
+    }
+
+    /**
+     * Return errors when sent data are either missing or invalid.
+     */
+    public function test_set_invalid_data(): void {
+        $user = User::factory()->create();
+
+        Auth::login($user);
+
+        $missingData = $this->postJson("/cart/set");
+        $missingData->assertInvalid(["product", "amount"]);
+
+        $invalidData = $this->postJson(
+            "/cart/set",
+            [
+                "product" => 1,
+                "amount" => -5
+            ]
+        );
+
+        $invalidData->assertInvalid(["product", "amount"]);
+    }
+
+    /**
+     * Successfully set item when valid arguments are given.
+     */
+    public function test_set_successful() {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        Auth::login($user);
+
+        $response = $this->postJson(
+            "/cart/set",
+            [
+                "product" => $product->id,
+                "amount" => 5
+            ]
+        );
+
+        $response->assertSuccessful();
+        $this->assertEquals(5, $user->cart()->find($product)->pivot->amount);
+    }
+
+    /**
+     * Return errors when sent data are either missing or invalid.
+     */
+    public function test_remove_invalid_data(): void {
+        $user = User::factory()->create();
+
+        Auth::login($user);
+
+        $missingData = $this->postJson("/cart/remove");
+        $missingData->assertInvalid(["product"]);
+
+        $invalidData = $this->postJson(
+            "/cart/set",
+            [
+                "product" => 1
+            ]
+        );
+
+        $invalidData->assertInvalid(["product"]);
+    }
+
+    /**
+     * Successfully remove item from cart when valid arguments are given.
+     */
+    public function test_remove_successful() {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        Auth::login($user);
+
+        $response = $this->postJson(
+            "/cart/remove",
+            [
+                "product" => $product->id,
+            ]
+        );
+
+        $response->assertSuccessful();
+        $this->assertEquals(null, $user->cart()->find($product));
+    }
+}

tests/Unit/CartTest.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Models\Product;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+use function PHPUnit\Framework\assertEquals;
+use function PHPUnit\Framework\assertTrue;
+
+class CartTest extends TestCase {
+    use RefreshDatabase;
+
+    /**
+     * Get user's cart items.
+     */
+    public function test_get_items() {
+        $products = Product::factory()->count(5)->create();
+        $user = User::factory()->create();
+
+        foreach ($products as $product) {
+            $user->cart()->attach($product, ["amount" => 1]);
+        }
+
+        foreach ($user->getCartItems() as $item) {
+            $exists = false;
+
+            foreach ($products as $product) {
+                if($product->id == $item->id) {
+                    $exists = true;
+                    break;
+                }
+            }
+
+            assertTrue($exists);
+        }
+    }
+
+    /**
+     * Add product to cart with given amount and increase it if it exists.
+     */
+    public function test_add_item(): void {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        $user->addCartItem($product, 5);
+        $this->assertEquals(5, $user->getAmount($product));
+
+        $user->addCartItem($product, 5);
+        $this->assertEquals(10, $user->getAmount($product));
+    }
+
+    /**
+     * Set product with given amount in cart.
+     */
+    public function test_set_item(): void {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        $user->setCartItem($product, 5);
+        $this->assertEquals(5, $user->getAmount($product));
+    }
+
+    /**
+     * Remove product from cart.
+     */
+    public function test_remove_item(): void {
+        $user = User::factory()->create();
+        $product = Product::factory()->create();
+
+        $user->cart()->attach($product, ["amount" => 1]);
+
+        $user->removeCartItem($product);
+        assertEquals(0, $user->cart()->count());
+    }
+}