[TASK] Use strict equality

One instance is left out, but is covered by #1330.

Author: JakeQZ

src/CSSList/CSSList.php

@@ -208,7 +208,7 @@ private static function parseAtRule(ParserState $parserState): ?CSSListItem
         } else {
             // Unknown other at rule (font-face or such)
             $arguments = \trim($parserState->consumeUntil('{', false, true));
-            if (\substr_count($arguments, '(') != \substr_count($arguments, ')')) {
+            if (\substr_count($arguments, '(') !== \substr_count($arguments, ')')) {
                 if ($parserState->getSettings()->usesLenientParsing()) {
                     return null;
                 } else {

src/Value/CalcFunction.php

@@ -30,7 +30,7 @@ public static function parse(ParserState $parserState, bool $ignoreCase = false)
     {
         $operators = ['+', '-', '*', '/'];
         $function = $parserState->parseIdentifier();
-        if ($parserState->peek() != '(') {
+        if ($parserState->peek() !== '(') {
             // Found ; or end of line before an opening bracket
             throw new UnexpectedTokenException('(', $parserState->peek(), 'literal', $parserState->currentLine());
         } elseif ($function !== 'calc') {
@@ -59,15 +59,15 @@ public static function parse(ParserState $parserState, bool $ignoreCase = false)
                 $parserState->consumeWhiteSpace();
                 continue;
             }
-            if ($lastComponentType != CalcFunction::T_OPERAND) {
+            if ($lastComponentType !== CalcFunction::T_OPERAND) {
                 $value = Value::parsePrimitiveValue($parserState);
                 $calcRuleValueList->addListComponent($value);
                 $lastComponentType = CalcFunction::T_OPERAND;
             } else {
                 if (\in_array($parserState->peek(), $operators, true)) {
                     if (($parserState->comes('-') || $parserState->comes('+'))) {
                         if (
-                            $parserState->peek(1, -1) != ' '
+                            $parserState->peek(1, -1) !== ' '
                             || !($parserState->comes('- ')
                                 || $parserState->comes('+ '))
                         ) {

src/Value/Color.php

@@ -289,7 +289,7 @@ private function renderAsHex(): string
             $this->components['g']->getSize(),
             $this->components['b']->getSize()
         );
-        $canUseShortVariant = ($result[0] == $result[1]) && ($result[2] == $result[3]) && ($result[4] == $result[5]);
+        $canUseShortVariant = ($result[0] === $result[1]) && ($result[2] === $result[3]) && ($result[4] === $result[5]);
 
         return '#' . ($canUseShortVariant ? $result[0] . $result[2] . $result[4] : $result);
     }

src/Value/Size.php

@@ -189,7 +189,7 @@ public function isRelative(): bool
         if (\in_array($this->unit, self::RELATIVE_SIZE_UNITS, true)) {
             return true;
         }
-        if ($this->unit === null && $this->size != 0) {
+        if ($this->unit === null && $this->size !== 0.0) {
             return true;
         }
         return false;