From 83aa9a1431f7398306710f40f8252cbc5760fb04 Mon Sep 17 00:00:00 2001
From: Joel Male <joel@joelmale.com>
Date: Wed, 27 May 2026 20:59:45 +1000
Subject: [PATCH] feat: add MultiDriver

---
 src/Drivers/MultiDriver.php            | 84 ++++++++++++++++++++++++++
 tests/Unit/Drivers/MultiDriverTest.php | 80 ++++++++++++++++++++++++
 2 files changed, 164 insertions(+)
 create mode 100644 src/Drivers/MultiDriver.php
 create mode 100644 tests/Unit/Drivers/MultiDriverTest.php

diff --git a/src/Drivers/MultiDriver.php b/src/Drivers/MultiDriver.php
new file mode 100644
index 0000000..4278006
--- /dev/null
+++ b/src/Drivers/MultiDriver.php
@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Wearepixel\Cart\Drivers;
+
+use InvalidArgumentException;
+use Wearepixel\Cart\Drivers\Contracts\CartDriver;
+
+class MultiDriver implements CartDriver
+{
+    /** @param CartDriver[] $drivers */
+    public function __construct(private array $drivers)
+    {
+        if (empty($drivers)) {
+            throw new InvalidArgumentException('MultiDriver requires at least one driver.');
+        }
+    }
+
+    private function primary(): CartDriver
+    {
+        return $this->drivers[0];
+    }
+
+    public function getSessionKey(): string
+    {
+        return $this->primary()->getSessionKey();
+    }
+
+    public function setSessionKey(string $sessionKey): void
+    {
+        foreach ($this->drivers as $driver) {
+            $driver->setSessionKey($sessionKey);
+        }
+    }
+
+    public function getDriverName(): string
+    {
+        return 'multi';
+    }
+
+    public function getItems(): array
+    {
+        return $this->primary()->getItems();
+    }
+
+    public function putItems(array $items): void
+    {
+        foreach ($this->drivers as $driver) {
+            $driver->putItems($items);
+        }
+    }
+
+    public function getConditions(): array
+    {
+        return $this->primary()->getConditions();
+    }
+
+    public function putConditions(array $conditions): void
+    {
+        foreach ($this->drivers as $driver) {
+            $driver->putConditions($conditions);
+        }
+    }
+
+    public function clearItems(): void
+    {
+        foreach ($this->drivers as $driver) {
+            $driver->clearItems();
+        }
+    }
+
+    public function flush(): void
+    {
+        foreach ($this->drivers as $driver) {
+            $driver->flush();
+        }
+    }
+
+    public function getSessionModel(): mixed
+    {
+        return $this->primary()->getSessionModel();
+    }
+}
diff --git a/tests/Unit/Drivers/MultiDriverTest.php b/tests/Unit/Drivers/MultiDriverTest.php
new file mode 100644
index 0000000..0a16a9a
--- /dev/null
+++ b/tests/Unit/Drivers/MultiDriverTest.php
@@ -0,0 +1,80 @@
+<?php
+
+declare(strict_types=1);
+
+use Wearepixel\Cart\Drivers\MultiDriver;
+use Wearepixel\Cart\Drivers\NullDriver;
+
+describe('MultiDriver', function () {
+    beforeEach(function () {
+        $this->primary = new NullDriver('test-session');
+        $this->secondary = new NullDriver('test-session');
+        $this->driver = new MultiDriver([$this->primary, $this->secondary]);
+    });
+
+    test('returns session key from primary driver', function () {
+        expect($this->driver->getSessionKey())->toBe('test-session');
+    });
+
+    test('returns multi as driver name', function () {
+        expect($this->driver->getDriverName())->toBe('multi');
+    });
+
+    test('reads items from primary driver', function () {
+        $this->primary->putItems([['id' => 1]]);
+        $this->secondary->putItems([['id' => 2]]);
+
+        expect($this->driver->getItems())->toBe([['id' => 1]]);
+    });
+
+    test('writes items to all drivers', function () {
+        $this->driver->putItems([['id' => 1]]);
+
+        expect($this->primary->getItems())->toBe([['id' => 1]]);
+        expect($this->secondary->getItems())->toBe([['id' => 1]]);
+    });
+
+    test('reads conditions from primary driver', function () {
+        $this->primary->putConditions([['name' => 'GST']]);
+        $this->secondary->putConditions([['name' => 'Other']]);
+
+        expect($this->driver->getConditions())->toBe([['name' => 'GST']]);
+    });
+
+    test('writes conditions to all drivers', function () {
+        $this->driver->putConditions([['name' => 'GST']]);
+
+        expect($this->primary->getConditions())->toBe([['name' => 'GST']]);
+        expect($this->secondary->getConditions())->toBe([['name' => 'GST']]);
+    });
+
+    test('clearItems clears items on all drivers', function () {
+        $this->driver->putItems([['id' => 1]]);
+        $this->driver->clearItems();
+
+        expect($this->primary->getItems())->toBe([]);
+        expect($this->secondary->getItems())->toBe([]);
+    });
+
+    test('flush flushes all drivers', function () {
+        $this->driver->putItems([['id' => 1]]);
+        $this->driver->putConditions([['name' => 'GST']]);
+        $this->driver->flush();
+
+        expect($this->primary->getItems())->toBe([]);
+        expect($this->primary->getConditions())->toBe([]);
+        expect($this->secondary->getItems())->toBe([]);
+        expect($this->secondary->getConditions())->toBe([]);
+    });
+
+    test('setSessionKey updates all drivers', function () {
+        $this->driver->setSessionKey('new-key');
+
+        expect($this->primary->getSessionKey())->toBe('new-key');
+        expect($this->secondary->getSessionKey())->toBe('new-key');
+    });
+
+    test('throws when constructed with no drivers', function () {
+        expect(fn() => new MultiDriver([]))->toThrow(InvalidArgumentException::class);
+    });
+});