Define default variable values in cases when they can be undefined

lib/API/JSON/v1/Forms.php

@@ -172,6 +172,7 @@ class Forms extends APIEndpoint {
     // check if the user gets to pick his own lists
     // or if it's selected by the admin
     $has_segment_selection = false;
+    $list_selection = [];
     foreach($body as $i => $block) {
       if($block['type'] === 'segment') {
         $has_segment_selection = true;

lib/Cron/Workers/SendingQueue/Migration.php

@@ -24,6 +24,9 @@ class Migration extends SimpleWorker {
 
   function prepareTask(ScheduledTask $task) {
     $unmigrated_columns = self::checkUnmigratedColumnsExist();
+    $unmigrated_queues_count = 0;
+    $unmigrated_queue_subscribers = [];
+
     if($unmigrated_columns) {
       $unmigrated_queues_count = $this->getUnmigratedQueues()->count();
       $unmigrated_queue_subscribers = $this->getTaskIdsForUnmigratedSubscribers();

lib/Form/Block/Html.php

@@ -5,6 +5,7 @@ class Html {
 
   static function render($block) {
     $html = '';
+    $text = '';
 
     if(isset($block['params']['text']) && $block['params']['text']) {
       $text = html_entity_decode($block['params']['text'], ENT_QUOTES);

lib/Newsletter/Scheduler/Scheduler.php

@@ -147,7 +147,7 @@ class Scheduler {
   }
 
   static function createPostNotificationSendingTask($newsletter) {
-    $existing_notification_history = Newsletter::table_alias('newsletters')
+    $existing_notification_history = Newsletter::tableAlias('newsletters')
       ->where('newsletters.parent_id', $newsletter->id)
       ->where('newsletters.type', Newsletter::TYPE_NOTIFICATION_HISTORY)
       ->where('newsletters.status', Newsletter::STATUS_SENDING)
@@ -194,9 +194,6 @@ class Scheduler {
       $newsletter->nthWeekDay :
       '#' . $newsletter->nthWeekDay;
     switch($interval_type) {
-      case self::INTERVAL_IMMEDIATELY:
-        $schedule = '* * * * *';
-        break;
       case self::INTERVAL_IMMEDIATE:
       case self::INTERVAL_DAILY:
         $schedule = sprintf('0 %s * * *', $hour);
@@ -210,6 +207,10 @@ class Scheduler {
       case self::INTERVAL_MONTHLY:
         $schedule = sprintf('0 %s %s * *', $hour, $month_day);
         break;
+      case self::INTERVAL_IMMEDIATELY:
+      default:
+        $schedule = '* * * * *';
+        break;
     }
     $option_field = NewsletterOptionField::where('name', 'schedule')->findOne();
     $relation = NewsletterOption::where('newsletter_id', $newsletter->id)

lib/Subscribers/ImportExport/Import/Import.php

@@ -194,6 +194,7 @@ class Import {
   }
 
   function transformSubscribersData($subscribers, $columns) {
+    $transformed_subscribers = [];
     foreach($columns as $column => $data) {
       $transformed_subscribers[$column] = array_column($subscribers, $data['index']);
     }
@@ -227,6 +228,7 @@ class Import {
     $wp_users = array_filter(array_column($temp_existing_subscribers, 'wp_user_id'));
     // create a new two-dimensional associative array with existing subscribers ($existing_subscribers)
     // and reduce $subscribers_data to only new subscribers by removing existing subscribers
+    $existing_subscribers = [];
     $subscribers_emails = array_flip($subscribers_data['email']);
     foreach($temp_existing_subscribers as $temp_existing_subscriber) {
       $existing_subscriber_key = $subscribers_emails[$temp_existing_subscriber['email']];

lib/Subscribers/ImportExport/Import/MailChimp.php

@@ -45,6 +45,7 @@ class MailChimp {
       return $this->throwException('API');
     }
 
+    $lists = [];
     foreach($response->data as $list) {
       $lists[] = array(
         'id' => $list->id,
@@ -65,6 +66,8 @@ class MailChimp {
     }
 
     $bytes_fetched = 0;
+    $subscribers = [];
+    $header = [];
     foreach($lists as $list) {
       $url = sprintf($this->export_url, $this->data_center, $this->api_key, $list);
       $connection = @fopen($url, 'r');
@@ -72,7 +75,6 @@ class MailChimp {
         return $this->throwException('connection');
       }
       $i = 0;
-      $header = array();
       while(!feof($connection)) {
         $buffer = fgets($connection, 4096);
         if(trim($buffer) !== '') {
@@ -124,6 +126,7 @@ class MailChimp {
   }
 
   function throwException($error) {
+    $errorMessage = __('Unknown MailChimp error message.', 'mailpoet');
     switch($error) {
       case 'API':
         $errorMessage = __('Invalid API Key.', 'mailpoet');