[TASK] Have comsumeWhiteSpace() return the consumed

Instead have the comments array passed by reference to be appended to.
This avoids various methods having to do an `array_merge`, and knowing if any
whitespace was consumed will be needed for #1471.

Author: JakeQZ

src/CSSList/CSSList.php

@@ -68,7 +68,7 @@ public static function parseList(ParserState $parserState, CSSList $list): void
         $usesLenientParsing = $parserState->getSettings()->usesLenientParsing();
         $comments = [];
         while (!$parserState->isEnd()) {
-            $comments = \array_merge($comments, $parserState->consumeWhiteSpace());
+            $parserState->consumeWhiteSpace($comments);
             $listItem = null;
             if ($usesLenientParsing) {
                 try {
@@ -93,7 +93,8 @@ public static function parseList(ParserState $parserState, CSSList $list): void
                 $listItem->addComments($comments);
                 $list->append($listItem);
             }
-            $comments = $parserState->consumeWhiteSpace();
+            $comments = [];
+            $parserState->consumeWhiteSpace($comments);
         }
         $list->addComments($comments);
         if (!$isRoot && !$usesLenientParsing) {

src/Parsing/ParserState.php

@@ -188,7 +188,7 @@ public function parseCharacter(bool $isForIdentifier): ?string
     }
 
     /**
-     * @return list<Comment>
+     * @param list<Comment> $comments
      *
      * @throws UnexpectedEOFException
      * @throws UnexpectedTokenException
@@ -197,12 +197,12 @@ public function parseCharacter(bool $isForIdentifier): ?string
      * This method may change the state of the object by advancing the internal position;
      * it does not simply 'get' a value.
      */
-    public function consumeWhiteSpace(): array
+    public function consumeWhiteSpace(array &$comments = []): string
     {
-        $comments = [];
+        $consumed = '';
         do {
             while (preg_match('/\\s/isSu', $this->peek()) === 1) {
-                $this->consume(1);
+                $consumed .= $this->consume(1);
             }
             if ($this->parserSettings->usesLenientParsing()) {
                 try {
@@ -219,7 +219,7 @@ public function consumeWhiteSpace(): array
             }
         } while ($comment instanceof Comment);
 
-        return $comments;
+        return $consumed;
     }
 
     /**

src/Rule/Rule.php

@@ -65,14 +65,15 @@ public function __construct(string $rule, ?int $lineNumber = null, ?int $columnN
      */
     public static function parse(ParserState $parserState, array $commentsBeforeRule = []): Rule
     {
-        $comments = \array_merge($commentsBeforeRule, $parserState->consumeWhiteSpace());
+        $comments = $commentsBeforeRule;
+        $parserState->consumeWhiteSpace($comments);
         $rule = new Rule(
             $parserState->parseIdentifier(!$parserState->comes('--')),
             $parserState->currentLine(),
             $parserState->currentColumn()
         );
+        $parserState->consumeWhiteSpace($comments);
         $rule->setComments($comments);
-        $rule->addComments($parserState->consumeWhiteSpace());
         $parserState->consume(':');
         $value = Value::parseValue($parserState, self::listDelimiterForRule($rule->getRule()));
         $rule->setValue($value);

src/RuleSet/RuleSet.php

@@ -59,7 +59,8 @@ public static function parseRuleSet(ParserState $parserState, RuleSet $ruleSet):
             $parserState->consume(';');
         }
         while (true) {
-            $commentsBeforeRule = $parserState->consumeWhiteSpace();
+            $commentsBeforeRule = [];
+            $parserState->consumeWhiteSpace($commentsBeforeRule);
             if ($parserState->comes('}')) {
                 break;
             }