Use ctype_digit instead of is_numeric

Author: AydinHassan

src/MenuStyle.php

@@ -202,13 +202,13 @@ public function getDisabledItemText(string $text) : string
      */
     private function generateColoursSetCode() : void
     {
-        if (!is_numeric($this->fg)) {
+        if (!ctype_digit($this->fg)) {
             $fgCode = self::$availableForegroundColors[$this->fg];
         } else {
             $fgCode = sprintf("38;5;%s", $this->fg);
         }
 
-        if (!is_numeric($this->bg)) {
+        if (!ctype_digit($this->bg)) {
             $bgCode = self::$availableBackgroundColors[$this->bg];
         } else {
             $bgCode = sprintf("48;5;%s", $this->bg);

src/Util/ColourUtil.php

@@ -308,7 +308,7 @@ public static function map256To8(int $colourCode) : string
      */
     public static function validateColour(Terminal $terminal, string $colour, string $fallback = null) : string
     {
-        if (!is_numeric($colour)) {
+        if (!ctype_digit($colour)) {
             return static::validateColourName($colour);
         }
 

test/CliMenuBuilderTest.php

@@ -145,7 +145,7 @@ public function testSetBgThrowsExceptionWhenColourCodeIsNotInRange() : void
 
         $builder = new CliMenuBuilder;
         $builder->setTerminal($terminal);
-        $builder->setBackgroundColour(-5, 'white');
+        $builder->setBackgroundColour(257, 'white');
     }
 
     public function testDisableDefaultItems() : void

test/MenuStyleTest.php

@@ -164,7 +164,7 @@ public function testSetBgThrowsExceptionWhenColourCodeIsNotInRange() : void
         $this->expectExceptionMessage('Invalid colour code');
 
         $style = $this->getMenuStyle(256);
-        $style->setBg(-5, 'white');
+        $style->setBg(257, 'white');
     }
 
     public function testGetMarkerReturnsTheCorrectMarkers() : void