Adds unit test

lib/Cron/Workers/SendingQueue/Migration.php

@@ -8,6 +8,7 @@ use MailPoet\Mailer\MailerLog;
 use MailPoet\Models\ScheduledTask;
 use MailPoet\Models\ScheduledTaskSubscriber;
 use MailPoet\Models\SendingQueue;
+use MailPoet\WP\Functions as WPFunctions;
 
 if(!defined('ABSPATH')) exit;
 
@@ -242,6 +243,6 @@ class Migration extends SimpleWorker {
 
   static function getNextRunDate() {
     // run migration immediately
-    return Carbon::createFromTimestamp(current_time('timestamp'));
+    return Carbon::createFromTimestamp(WPFunctions::currentTime('timestamp'));
   }
 }

lib/WP/Functions.php

@@ -22,6 +22,10 @@ class Functions {
     return self::callWithFallback('wp_remote_retrieve_response_message', func_get_args());
   }
 
+  static function currentTime() {
+    return self::callWithFallback('current_time', func_get_args());
+  }
+
   private static function callWithFallback($func, $args) {
     $local_func = __NAMESPACE__ . '\\' . $func;
     if(function_exists($local_func)) {

tests/_support/Helper/WordPress.php

@@ -71,3 +71,7 @@ function wp_remote_post() {
 function wp_remote_get() {
   return override(__FUNCTION__, func_get_args());
 }
+
+function current_time() {
+  return override(__FUNCTION__, func_get_args());
+}

tests/unit/Cron/Workers/SendingQueue/MigrationTest.php

@@ -2,6 +2,7 @@
 namespace MailPoet\Test\Cron\Workers;
 
 use Carbon\Carbon;
+use Helper\WordPress as WordPressHelper;
 use MailPoet\Cron\Workers\SendingQueue\Migration;
 use MailPoet\Mailer\MailerLog;
 use MailPoet\Models\ScheduledTask;
@@ -107,6 +108,20 @@ class MigrationTest extends \MailPoetTest {
     expect(MailerLog::isSendingPaused())->false();
   }
 
+  function testItUsesWPTimeToReturnNextRunDate() {
+    $timestamp = 1514801410; // 01/01/2018 @ 10:10am (UTC)
+
+    WordPressHelper::interceptFunction('current_time', function($time) use($timestamp) {
+      // "timestamp" string is passed as an argument
+      expect($time)->equals('timestamp');
+
+      return $timestamp;
+    });
+
+    $next_run_date = Migration::getNextRunDate();
+    expect($next_run_date->timestamp)->equals($timestamp);
+  }
+
   private function createScheduledTask() {
     $task = ScheduledTask::create();
     $task->type = Migration::TASK_TYPE;
@@ -185,5 +200,7 @@ class MigrationTest extends \MailPoetTest {
       $this->restoreTable();
       $this->altered = false;
     }
+
+    WordPressHelper::releaseAllFunctions();
   }
 }