diff --git a/src/Traits/TestCaseTrait.php b/src/Traits/TestCaseTrait.php
new file mode 100644
index 00000000..b806eb91
--- /dev/null
+++ b/src/Traits/TestCaseTrait.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace Apiato\Core\Traits;
+
+use Laravel\Passport\ClientRepository;
+use Laravel\Passport\PersonalAccessClient;
+
+trait TestCaseTrait
+{
+    /**
+     * Override default URL subDomain in case you want to change it for some tests.
+     *
+     * @param null $url
+     *
+     * @return string|void
+     */
+    public function overrideSubDomain($url = null)
+    {
+        // `subDomain` is a property defined in your class.
+        if (!property_exists($this, 'subDomain')) {
+            return;
+        }
+
+        $url = ($url) ?: $this->baseUrl;
+
+        $info = parse_url($url);
+
+        $array = explode('.', $info['host']);
+
+        $withoutDomain = (array_key_exists(
+            count($array) - 2,
+            $array,
+        ) ? $array[count($array) - 2] : '') . '.' . $array[count($array) - 1];
+
+        $newSubDomain = $info['scheme'] . '://' . $this->subDomain . '.' . $withoutDomain;
+
+        return $this->baseUrl = $newSubDomain;
+    }
+
+    /**
+     * Equivalent to passport:install but enough to run the tests.
+     */
+    public function setupPassportOAuth2(): void
+    {
+        $client = (new ClientRepository())->createPersonalAccessClient(
+            null,
+            'Testing Personal Access Client',
+            'http://localhost',
+        );
+
+        $accessClient = new PersonalAccessClient();
+        $accessClient->client_id = $client->id;
+        $accessClient->save();
+    }
+}