[CLEANUP] Clean extra whitespace in css selector

CHANGELOG.md

@@ -14,6 +14,7 @@ Please also have a look at our
 
 ### Changed
 
+- Cleanup extra whitespace in css selector (#1398)
 - The array keys passed to `DeclarationBlock::setSelectors()` are no longer
   preserved (#1407)
 

src/Property/Selector.php

@@ -9,6 +9,7 @@
 use Sabberworm\CSS\Renderable;
 
 use function Safe\preg_match;
+use function Safe\preg_replace;
 
 /**
  * Class representing a single CSS selector. Selectors have to be split by the comma prior to being passed into this
@@ -74,7 +75,12 @@ public function getSelector(): string
 
     public function setSelector(string $selector): void
     {
-        $this->selector = \trim($selector);
+        $selector = \trim($selector);
+
+        $hasAttribute = \strpos($selector, '[') !== false;
+
+        // Whitespace can't be adjusted within an attribute selector, as it would change its meaning
+        $this->selector = !$hasAttribute ? preg_replace('/\\s++/', ' ', $selector) : $selector;
     }
 
     /**

tests/ParserTest.php

@@ -770,7 +770,7 @@ public function selectorIgnoresInFile(): void
         $document = self::parsedStructureForFile('selector-ignores', Settings::create()->withMultibyteSupport(true));
         $expected = '.some[selectors-may=\'contain-a-{\'] {}'
             . "\n"
-            . '.this-selector  .valid {width: 100px;}'
+            . '.this-selector .valid {width: 100px;}'
             . "\n"
             . '@media only screen and (min-width: 200px) {.test {prop: val;}}';
         self::assertSame($expected, $document->render());

tests/Unit/Property/SelectorTest.php

@@ -141,4 +141,51 @@ public function isValidForInvalidSelectorReturnsFalse(string $selector): void
     {
         self::assertFalse(Selector::isValid($selector));
     }
+
+    /**
+     * @test
+     */
+    public function cleansUpSpacesWithinSelector(): void
+    {
+        $selector = 'p   >    small';
+
+        $subject = new Selector($selector);
+
+        self::assertSame('p > small', $subject->getSelector());
+    }
+
+    /**
+     * @test
+     */
+    public function cleansUpTabsWithinSelector(): void
+    {
+        $selector = "p\t>\tsmall";
+
+        $subject = new Selector($selector);
+
+        self::assertSame('p > small', $subject->getSelector());
+    }
+
+    /**
+     * @test
+     */
+    public function cleansUpNewLineWithinSelector(): void
+    {
+        $selector = "p\n>\nsmall";
+
+        $subject = new Selector($selector);
+
+        self::assertSame('p > small', $subject->getSelector());
+    }
+
+
+    /**
+     * @test
+     */
+    public function doesNotCleanupSpacesWithinAttributeSelector(): void
+    {
+        $subject = new Selector('a[title="extra  space"]');
+
+        self::assertSame('a[title="extra  space"]', $subject->getSelector());
+    }
 }