diff --git a/.travis.yml b/.travis.yml
index c7e9603f..91d06a2f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ git:
 cache:
   directories:
   - vendor
+  - plugins
   - node_modules
 
 env:
@@ -19,6 +20,7 @@ before_script:
 - mysql -e 'CREATE DATABASE IF NOT EXISTS test;'
 - php artisan key:random
 - php artisan salt:random
+- php -f ./tests/scripts/download-plugins.php
 
 script: ./vendor/bin/phpunit
 
diff --git a/app/Http/Controllers/PluginController.php b/app/Http/Controllers/PluginController.php
index d54927f8..e3886e63 100644
--- a/app/Http/Controllers/PluginController.php
+++ b/app/Http/Controllers/PluginController.php
@@ -10,6 +10,9 @@ use App\Services\PluginManager;
 
 class PluginController extends Controller
 {
+    /**
+     * @codeCoverageIgnore
+     */
     public function showMarket()
     {
         return redirect('/')->setTargetUrl(
@@ -29,7 +32,7 @@ class PluginController extends Controller
         if ($plugin && $plugin->isEnabled() && $plugin->hasConfigView()) {
             return $plugin->getConfigView();
         } else {
-            abort(404, trans('admin.plugins.operations.no-config-notice'));
+            return abort(404, trans('admin.plugins.operations.no-config-notice'));
         }
     }
 
@@ -58,9 +61,10 @@ class PluginController extends Controller
                     return json(trans('admin.plugins.operations.deleted'), 0);
 
                 default:
-                    # code...
-                    break;
+                    return json(trans('admin.invalid-action'), 1);
             }
+        } else {
+            return json(trans('admin.plugins.operations.not-found'), 1);
         }
     }
 
diff --git a/app/Services/PluginManager.php b/app/Services/PluginManager.php
index 712e1835..97665264 100644
--- a/app/Services/PluginManager.php
+++ b/app/Services/PluginManager.php
@@ -175,7 +175,7 @@ class PluginManager
 
         $this->disable($name);
 
-        // fire event before deleeting plugin files
+        // fire event before deleting plugin files
         $this->dispatcher->fire(new Events\PluginWasDeleted($plugin));
 
         $this->filesystem->deleteDirectory($plugin->getPath());
diff --git a/app/helpers.php b/app/helpers.php
index a4895f0f..693ecb72 100644
--- a/app/helpers.php
+++ b/app/helpers.php
@@ -51,6 +51,10 @@ if (! function_exists('assets')) {
 
 if (! function_exists('plugin')) {
 
+    /**
+     * @param string $id
+     * @return \App\Services\Plugin
+     */
     function plugin($id)
     {
         return app('plugins')->getPlugin($id);
diff --git a/resources/lang/en/admin.yml b/resources/lang/en/admin.yml
index 27a81d73..276cb972 100644
--- a/resources/lang/en/admin.yml
+++ b/resources/lang/en/admin.yml
@@ -108,6 +108,7 @@ plugins:
     disabled: :plugin has been disabled.
     deleted: The plugin was deleted successfully.
     no-config-notice: The plugin is not installed or doesn't provide configuration page.
+    not-found: No such plugin.
 
   empty: No result
 
@@ -155,3 +156,5 @@ update:
     write-permission: Unable to make cache directory. Please sure permission.
     unzip: "Failed to unzip update file. Error code: "
     overwrite: Unable to overwrite files.
+
+invalid-action: Invalid action
diff --git a/resources/lang/zh_CN/admin.yml b/resources/lang/zh_CN/admin.yml
index 8b4318dd..b00f2851 100644
--- a/resources/lang/zh_CN/admin.yml
+++ b/resources/lang/zh_CN/admin.yml
@@ -108,6 +108,7 @@ plugins:
     disabled: :plugin 已禁用
     deleted: 插件已被成功删除
     no-config-notice: 插件未安装或未提供配置页面
+    not-found: 插件不存在
 
   empty: 无结果
 
@@ -155,3 +156,5 @@ update:
     write-permission: 您的服务器不支持自动更新：创建下载缓存文件夹失败，请检查目录权限。
     unzip: 更新包解压缩失败。错误代码：
     overwrite: 您的服务器不支持自动更新：无法覆盖文件。
+
+invalid-action: 无效的操作名
diff --git a/tests/PluginControllerTest.php b/tests/PluginControllerTest.php
new file mode 100644
index 00000000..7e5307fd
--- /dev/null
+++ b/tests/PluginControllerTest.php
@@ -0,0 +1,114 @@
+<?php
+
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class PluginControllerTest extends TestCase
+{
+    use DatabaseTransactions;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        return $this->actAs('admin');
+    }
+
+    public function testShowManage()
+    {
+        $this->visit('/admin/plugins/manage')
+            ->see(trans('general.plugin-manage'));
+    }
+
+    public function testConfig()
+    {
+        // Plugin is disabled
+        $this->get('/admin/plugins/config/example-plugin')
+            ->see(trans('admin.plugins.operations.no-config-notice'))
+            ->assertResponseStatus(404);
+
+        // Plugin is enabled but it doesn't have config view
+        plugin('avatar-api')->setEnabled(true);
+        $this->get('/admin/plugins/config/avatar-api')
+            ->see(trans('admin.plugins.operations.no-config-notice'))
+            ->assertResponseStatus(404);
+
+        // Plugin has config view
+        plugin('example-plugin')->setEnabled(true);
+        $this->get('/admin/plugins/config/example-plugin')
+            ->assertResponseStatus(200);
+    }
+
+    public function testManage()
+    {
+        // An not-existed plugin
+        $this->post('/admin/plugins/manage', ['name' => 'nope'])
+            ->seeJson([
+                'errno' => 1,
+                'msg' => trans('admin.plugins.operations.not-found')
+            ]);
+
+        // Invalid action
+        $this->post('/admin/plugins/manage', ['name' => 'avatar-api'])
+            ->seeJson([
+                'errno' => 1,
+                'msg' => trans('admin.invalid-action')
+            ]);
+
+        // Enable a plugin
+        $this->expectsEvents(App\Events\PluginWasEnabled::class);
+        $this->post('/admin/plugins/manage', [
+            'name' => 'avatar-api',
+            'action' => 'enable'
+        ])->seeJson([
+            'errno' => 0,
+            'msg' => trans(
+                'admin.plugins.operations.enabled',
+                ['plugin' => plugin('avatar-api')->title]
+            )
+        ]);
+
+        // Disable a plugin
+        $this->post('/admin/plugins/manage', [
+            'name' => 'avatar-api',
+            'action' => 'disable'
+        ])->seeJson([
+            'errno' => 0,
+            'msg' => trans(
+                'admin.plugins.operations.disabled',
+                ['plugin' => plugin('avatar-api')->title]
+            )
+        ]);
+        $this->expectsEvents(App\Events\PluginWasDisabled::class);
+
+        // Delete a plugin
+        $this->post('/admin/plugins/manage', [
+            'name' => 'avatar-api',
+            'action' => 'delete'
+        ])->seeJson([
+            'errno' => 0,
+            'msg' => trans('admin.plugins.operations.deleted')
+        ]);
+        $this->expectsEvents(App\Events\PluginWasDeleted::class);
+        $this->assertFalse(file_exists(base_path('plugins/avatar-api/')));
+    }
+
+    public function testGetPluginData()
+    {
+        $this->get('/admin/plugins/data')
+            ->seeJsonStructure([
+                'data' => [[
+                    'name',
+                    'version',
+                    'path',
+                    'title',
+                    'description',
+                    'author' => ['author', 'url'],
+                    'url',
+                    'namespace',
+                    'status',
+                    'operations' => ['enabled', 'hasConfigView']
+                ]]
+            ]);
+    }
+}
diff --git a/tests/scripts/download-plugins.php b/tests/scripts/download-plugins.php
new file mode 100644
index 00000000..33ade77d
--- /dev/null
+++ b/tests/scripts/download-plugins.php
@@ -0,0 +1,57 @@
+<?php
+
+function success($message) {
+    return "\e[32m$message\e[0m\n";
+}
+
+function warning($message) {
+    return "\e[33m$message\e[0m\n";
+}
+
+function error($message) {
+    return "\e[31m$message\e[0m\n";
+}
+
+function getPlugin($plugin_name, $filename) {
+    if (!file_exists('./plugins/'.$plugin_name)) {
+        fwrite(STDOUT, warning("Cannot find plugin: $plugin_name"));
+
+        fwrite(STDOUT, "Downloading $plugin_name...\n");
+        $timer = microtime(true);
+        try {
+            file_put_contents(
+                './storage/'.$filename,
+                file_get_contents("https://github.com/printempw/blessing-skin-plugins/raw/master/dist/$filename")
+            );
+        } catch (Exception $e) {
+            fwrite(STDOUT, error("Failed to download plugin: $plugin_name."));
+            exit(1);
+        }
+        fwrite(STDOUT, success("Download plugin \"$plugin_name\" successfully."));
+
+        fwrite(STDOUT, "Unzipping...\n");
+        try {
+            $zip = new ZipArchive();
+            $zip->open('./storage/'.$filename);
+            $zip->extractTo('./plugins/');
+            $zip->close();
+            unlink('./storage/'.$filename);
+        } catch (Exception $e) {
+            fwrite(STDOUT, error("Failed to unzip!"));
+            exit(1);
+        }
+        $time_diff = round(microtime(true) - $timer, 3);
+        fwrite(STDOUT, success("Finished: \"$plugin_name\" in {$time_diff}s"));
+    } else {
+        fwrite(STDOUT, success("Plugin \"$plugin_name\" is existed. OK."));
+    }
+}
+
+$plugins = [
+    'example-plugin' => 'example-plugin_v1.0.zip',
+    'avatar-api'     => 'avatar-api_v1.1.zip'
+];
+
+foreach ($plugins as $plugin_name => $filename) {
+    getPlugin($plugin_name, $filename);
+}