test(model): add tests for "User" model

app/Models/User.php

@@ -78,7 +78,7 @@ class User extends Model
     {
         // compare directly if any responses is returned by event dispatcher
         if ($result = static::getEncryptedPwdFromEvent($rawPasswd, $this)) {
-            return hash_equals($this->password, $result);
+            return hash_equals($this->password, $result);     // @codeCoverageIgnore
         }
 
         return app('cipher')->verify($rawPasswd, $this->password, config('secure.salt'));
@@ -136,7 +136,7 @@ class User extends Model
         $responses = event(new EncryptUserPassword($new_passwd, $this));
 
         if (isset($responses[0])) {
-            $this->password = $responses[0];
+            $this->password = $responses[0];     // @codeCoverageIgnore
         } else {
             $this->password = app('cipher')->hash($new_passwd, config('secure.salt'));
         }

tests/ModelsTest/UserTest.php

@@ -0,0 +1,30 @@
+<?php
+
+use App\Models\User;
+use App\Services\Utils;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class UserTest extends TestCase
+{
+    use DatabaseTransactions;
+
+    public function testSign()
+    {
+        $user = factory(User::class)->make([
+            'last_sign_at' => Utils::getTimeFormatted(time())
+        ]);
+        $user->sign();
+        $this->assertFalse($user->sign());
+    }
+
+    public function testGetNickName()
+    {
+        $user = new User();
+        $this->assertEquals(
+            trans('general.unexistent-user'),
+            $user->getNickName()
+        );
+    }
+}