diff --git a/tests/Unit/Services/MetadataResolverServiceTest.php b/tests/Unit/Services/MetadataResolverServiceTest.php
new file mode 100644
index 0000000..d8c7528
--- /dev/null
+++ b/tests/Unit/Services/MetadataResolverServiceTest.php
@@ -0,0 +1,182 @@
+<?php
+
+namespace Tests\Unit\Services;
+
+use App\MetadataResolver\MetadataResolver;
+use App\MetadataResolver\ResolverCircuitBreakException;
+use App\MetadataResolver\UncaughtResolverException;
+use App\Services\MetadataResolveService;
+use Carbon\Carbon;
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Exception\ServerException;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Psr7\Response;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Mockery\MockInterface;
+use Tests\TestCase;
+
+class MetadataResolverServiceTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->seed();
+        Carbon::setTestNow('2020-07-21 19:19:19');
+    }
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+        Carbon::setTestNow();
+    }
+
+    public function testOnRuntimeException()
+    {
+        $this->mock(MetadataResolver::class, function (MockInterface $mock) {
+            $mock->shouldReceive('resolve')->andReturnUsing(function ($url) {
+                throw new \RuntimeException('Something happened!');
+            });
+        });
+
+        try {
+            $service = app()->make(MetadataResolveService::class);
+            $service->execute('http://example.com');
+        } catch (UncaughtResolverException $e) {
+            $this->assertDatabaseHas('metadata', [
+                'url' => 'http://example.com',
+                'error_at' => new Carbon('2020-07-21 19:19:19'),
+                'error_count' => 1,
+                'error_exception_class' => \RuntimeException::class,
+                'error_http_code' => null,
+                'error_body' => 'Something happened!',
+            ]);
+
+            return;
+        }
+        $this->fail();
+    }
+
+    public function testOnHttpClientError()
+    {
+        $handler = HandlerStack::create(new MockHandler([new Response(404)]));
+        $client = new Client(['handler' => $handler]);
+        $this->instance(Client::class, $client);
+
+        try {
+            $service = app()->make(MetadataResolveService::class);
+            $service->execute('http://example.com');
+        } catch (UncaughtResolverException $e) {
+            $this->assertDatabaseHas('metadata', [
+                'url' => 'http://example.com',
+                'error_at' => new Carbon('2020-07-21 19:19:19'),
+                'error_count' => 1,
+                'error_exception_class' => ClientException::class,
+                'error_http_code' => 404,
+            ]);
+
+            return;
+        }
+        $this->fail();
+    }
+
+    public function testOnHttpServerError()
+    {
+        $handler = HandlerStack::create(new MockHandler([new Response(503), new Response(503)]));
+        $client = new Client(['handler' => $handler]);
+        $this->instance(Client::class, $client);
+
+        try {
+            $service = app()->make(MetadataResolveService::class);
+            $service->execute('http://example.com');
+        } catch (UncaughtResolverException $e) {
+            $this->assertDatabaseHas('metadata', [
+                'url' => 'http://example.com',
+                'error_at' => new Carbon('2020-07-21 19:19:19'),
+                'error_count' => 1,
+                'error_exception_class' => ServerException::class,
+                'error_http_code' => 503,
+            ]);
+
+            return;
+        }
+        $this->fail();
+    }
+
+    public function testCircuitBreak()
+    {
+        $this->mock(MetadataResolver::class, function (MockInterface $mock) {
+            $mock->shouldReceive('resolve')->andReturnUsing(function ($url) {
+                throw new \RuntimeException('Something happened!');
+            });
+        });
+
+        try {
+            for ($i = 0; $i < 6; $i++) {
+                try {
+                    $service = app()->make(MetadataResolveService::class);
+                    $service->execute('http://example.com');
+                } catch (UncaughtResolverException $e) {
+                }
+            }
+        } catch (ResolverCircuitBreakException $e) {
+            $this->assertDatabaseHas('metadata', [
+                'url' => 'http://example.com',
+                'error_at' => new Carbon('2020-07-21 19:19:19'),
+                'error_count' => 5,
+                'error_exception_class' => \RuntimeException::class,
+                'error_http_code' => null,
+                'error_body' => 'Something happened!',
+            ]);
+
+            return;
+        }
+        $this->fail();
+    }
+
+    public function testOnResurrect()
+    {
+        $successBody = <<<HTML
+<!doctype html>
+<html lang="ja">
+<head>
+<meta charset="UTF-8">
+    <meta name="og:title" content="OGP Title">
+    <meta name="og:description" content="OGP Description">
+    <title>Test Document</title>
+</head>
+<body>
+</body>
+</html>
+HTML;
+        $handler = HandlerStack::create(new MockHandler([
+            new Response(404),
+            new Response(200, ['Content-Type' => 'text/html'], $successBody),
+        ]));
+        $client = new Client(['handler' => $handler]);
+        $this->instance(Client::class, $client);
+
+        for ($i = 0; $i < 2; $i++) {
+            try {
+                $service = app()->make(MetadataResolveService::class);
+                $service->execute('http://example.com');
+            } catch (UncaughtResolverException $e) {
+            }
+        }
+
+        $this->assertDatabaseHas('metadata', [
+            'url' => 'http://example.com',
+            'title' => 'OGP Title',
+            'description' => 'OGP Description',
+            'image' => '',
+            'error_at' => null,
+            'error_count' => 0,
+            'error_exception_class' => null,
+            'error_http_code' => null,
+            'error_body' => null,
+        ]);
+    }
+}