Issue #3190240: SliderProcessor adding results when nothing found

modules/facets_range_widget/src/Plugin/facets/processor/SliderProcessor.php

@@ -25,44 +25,63 @@ class SliderProcessor extends ProcessorPluginBase implements PostQueryProcessorI
    * {@inheritdoc}
    */
   public function postQuery(FacetInterface $facet) {
+    // Only consider facets with results.
+    $results = $facet->getResults();
+    if (empty($results)) {
+      return;
+    }
+
     $widget = $facet->getWidgetInstance();
     $config = $widget->getConfiguration();
-    $simple_results = [];
 
     // Generate all the "results" between min and max, with the configured step.
-    foreach ($facet->getResults() as $result) {
-      $simple_results['f_' . (float) $result->getRawValue()] = [
-        'value' => (float) $result->getRawValue(),
+    $simple_results = [];
+    foreach ($results as $result) {
+      $rawValue = (float) $result->getRawValue();
+      $simple_results['f_' . $rawValue] = [
+        'value' => $rawValue,
         'count' => (int) $result->getCount(),
       ];
     }
-    uasort($simple_results, function ($a, $b) {
+
+    uasort($simple_results, static function ($a, $b) {
       if ($a['value'] === $b['value']) {
         return 0;
       }
       return $a['value'] < $b['value'] ? -1 : 1;
     });
 
-    $step = $config['step'];
-    if ($config['min_type'] == 'fixed') {
+    // Compute min.
+    $min = reset($simple_results)['value'] ?? 0;
+    if (!empty($config['min_type']) && $config['min_type'] === 'fixed') {
       $min = $config['min_value'];
+    }
+
+    // Compute max.
+    $max = end($simple_results)['value'] ?? 0;
+    if (!empty($config['max_type']) && $config['max_type'] === 'fixed') {
       $max = $config['max_value'];
     }
-    else {
-      $min = reset($simple_results)['value'] ?? 0;
-      $max = end($simple_results)['value'] ?? 0;
-      // If max is not divisible by step, we should add the remainder to max to
-      // make sure that we don't lose any possible values.
-      if ($max % $step !== 0) {
-        $max = $max + ($step - $max % $step);
-      }
+
+    // Compute step.
+    if (!empty($config['step']) && $config['step'] > 0) {
+      $step = $config['step'];
+    } else {
+      $step = max(1, ceil($max / 100));
+    }
+
+    // If max is not divisible by step, we should add the remainder to max to
+    // make sure that we don't lose any possible values.
+    if ($max % $step !== 0) {
+      $max += ($step - $max % $step);
     }
 
     // Creates an array of all results between min and max by the step from the
     // configuration.
     $new_results = [];
     for ($i = $min; $i <= $max; $i += $step) {
-      $count = isset($simple_results['f_' . $i]) ? $simple_results['f_' . $i]['count'] : 0;
+      $new_result = $simple_results['f_' . $i] ?? NULL;
+      $count = $new_result !== NULL ? $new_result['count'] : 0;
       $new_results[] = new Result($facet, (float) $i, (float) $i, $count);
     }