Fix linter issues

Author: SerafimArts

src/Type/LowercaseString.php

@@ -35,11 +35,11 @@ private function isLowerString(string $value): bool
             return true;
         }
 
-        if (\function_exists('\\ctype_lower')) {
-            return \ctype_lower($value);
+        if (\function_exists('\\ctype_upper')) {
+            return !\ctype_upper($value);
         }
 
-        return !\preg_match('/[^a-z]/', $value);
+        return \preg_match('/[A-Z]/', $value) <= 0;
     }
 
     public function cast(mixed $value, Context $context): string

src/Type/NonZeroIntType.php

@@ -37,7 +37,7 @@ public function cast(mixed $value, Context $context): int
             $coerced = $this->coercer->coerce($value, $context);
         }
 
-        if (\is_int($value) && $value !== 0) {
+        if (\is_int($coerced) && $coerced !== 0) {
             return $coerced;
         }
 

src/Type/UppercaseString.php

@@ -35,11 +35,11 @@ private function isUpperString(string $value): bool
             return true;
         }
 
-        if (\function_exists('\\ctype_upper')) {
-            return \ctype_upper($value);
+        if (\function_exists('\\ctype_lower')) {
+            return !\ctype_lower($value);
         }
 
-        return !\preg_match('/[^A-Z]/', $value);
+        return \preg_match('/[a-z]/', $value) <= 0;
     }
 
     public function cast(mixed $value, Context $context): string