Fine tuning Rector configuration

Author: roberto-butti

rector.php

@@ -9,17 +9,17 @@
 
 return static function (RectorConfig $rectorConfig): void {
     $rectorConfig->paths([
-        __DIR__ . '/examples',
-        __DIR__ . '/src',
-        // __DIR__ . '/tests',
+        __DIR__ . "/examples",
+        __DIR__ . "/src",
+        __DIR__ . "/tests",
     ]);
 
     // register a single rule
     $rectorConfig->rule(InlineConstructorDefaultToPropertyRector::class);
 
     // define sets of rules
     $rectorConfig->sets([
-        LevelSetList::UP_TO_PHP_81,
+        LevelSetList::UP_TO_PHP_82,
         SetList::DEAD_CODE,
         SetList::CODE_QUALITY,
         SetList::EARLY_RETURN,

src/Stat.php

@@ -41,7 +41,7 @@ public static function mean(array $data): int|float|null
         if (self::count($data) === 0) {
             throw new InvalidDataInputException("The data must not be empty.");
         }
-        if (array_filter($data, "is_string") !== []) {
+        if (array_filter($data, is_string(...)) !== []) {
             throw new InvalidDataInputException(
                 "The data array contains a string.",
             );
@@ -77,7 +77,7 @@ public static function fmean(
 
         // Unweighted mean
         if ($weights === null) {
-            $sum = array_sum(array_map("floatval", $data));
+            $sum = array_sum(array_map(floatval(...), $data));
             $count = count($data);
             if ($precision) {
                 return round($sum / $count, $precision);
@@ -336,7 +336,7 @@ public static function pstdev(array $data, ?int $round = null): float
     public static function pvariance(array $data, ?int $round = null): float
     {
         $num_of_elements = self::count($data);
-        if ($num_of_elements == 0) {
+        if ($num_of_elements === 0) {
             throw new InvalidDataInputException("The data must not be empty.");
         }
         $sumSquareDifferences = 0.0;