Add unit tests

Author: coisa

tests/ContainerFunctionTest.php

@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of php-fast-forward/container.
+ *
+ * This source file is subject to the license bundled
+ * with this source code in the file LICENSE.
+ *
+ * @link      https://github.com/php-fast-forward/container
+ * @copyright Copyright (c) 2025 Felipe Sayão Lobato Abreu <github@mentordosnerds.com>
+ * @license   https://opensource.org/licenses/MIT MIT License
+ */
+
+namespace FastForward\Container\Tests;
+
+use FastForward\Config\ConfigInterface;
+use FastForward\Container\AggregateContainer;
+use FastForward\Container\Exception\NotFoundException;
+use FastForward\Container\Factory\ContainerFactory;
+use PHPUnit\Framework\Attributes\CoversFunction;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\Attributes\UsesClass;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+use Psr\Container\ContainerInterface;
+
+use function FastForward\Container\container;
+
+/**
+ * @internal
+ */
+#[CoversFunction('FastForward\Container\container')]
+#[UsesClass(AggregateContainer::class)]
+#[UsesClass(NotFoundException::class)]
+#[UsesClass(ContainerFactory::class)]
+final class ContainerFunctionTest extends TestCase
+{
+    use ProphecyTrait;
+
+    #[Test]
+    public function testContainerReturnsAggregateContainerWithDependencies(): void
+    {
+        $key   = uniqid('svc_', true);
+        $value = uniqid('val_', true);
+
+        $config = $this->prophesize(ConfigInterface::class);
+        $config->get('dependencies', [])->willReturn([
+            $key => static fn () => $value,
+        ]);
+        $config->has($key)->willReturn(false);
+
+        $result = container($config->reveal());
+
+        self::assertInstanceOf(AggregateContainer::class, $result);
+        self::assertTrue($result->has($key));
+        self::assertSame($value, $result->get($key));
+    }
+
+    #[Test]
+    public function testContainerCanMergeExternalContainers(): void
+    {
+        $key = uniqid('ext_', true);
+        $val = uniqid('external_', true);
+
+        $config = $this->prophesize(ConfigInterface::class);
+        $config->get('dependencies', [])->willReturn([]);
+        $config->has($key)->willReturn(false);
+
+        $external = $this->prophesize(ContainerInterface::class);
+        $external->has($key)->willReturn(true);
+        $external->get($key)->willReturn($val);
+
+        $result = container($config->reveal(), $external->reveal());
+
+        self::assertInstanceOf(AggregateContainer::class, $result);
+        self::assertTrue($result->has($key));
+        self::assertSame($val, $result->get($key));
+    }
+}