Add a test on the plugin client builder

Author: Taluu

tests/PluginClientBuilderTest.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace tests\Http\Client\Common;
+
+use Closure;
+use Http\Client\Common\Plugin;
+use Http\Client\Common\PluginClient;
+use Http\Client\Common\PluginClientBuilder;
+use Http\Client\HttpAsyncClient;
+use Http\Client\HttpClient;
+use PHPUnit\Framework\TestCase;
+
+class PluginClientBuilderTest extends TestCase
+{
+    /** @dataProvider clientProvider */
+    public function testPriority(string $client): void
+    {
+        $builder = new PluginClientBuilder();
+
+        $plugins = [
+            10 => $this->prophesize(Plugin::class)->reveal(),
+            -10 => $this->prophesize(Plugin::class)->reveal(),
+            0 => $this->prophesize(Plugin::class)->reveal(),
+        ];
+
+        foreach ($plugins as $priority => $plugin) {
+            $builder->addPlugin($plugin, $priority);
+        }
+
+        $client = $this->prophesize($client)->reveal();
+        $client = $builder->createClient($client);
+
+        $closure = Closure::bind(
+            function (): array {
+                return $this->plugins;
+            },
+            $client,
+            PluginClient::class
+        );
+
+        $plugged = $closure();
+
+        $expected = $plugins;
+        krsort($expected);
+        $expected = array_values($expected);
+
+        $this->assertSame($expected, $plugged);
+    }
+
+    public function clientProvider(): iterable
+    {
+        yield 'sync\'d http client' => [HttpClient::class];
+        yield 'async\'d http client' => [HttpAsyncClient::class];
+    }
+}