[TASK] Ensure Selector content is not whitespace-only

CHANGELOG.md

@@ -18,7 +18,7 @@ Please also have a look at our
 ### Changed
 
 - `Selector::setSelector()` and `Selector` constructor will now throw exception
-  upon provision of an invalid selectior (#1498)
+  upon provision of an invalid selectior (#1498, #1502)
 - Clean up extra whitespace in CSS selector (#1398)
 - The array keys passed to `DeclarationBlock::setSelectors()` are no longer
   preserved (#1407)

src/Property/Selector.php

@@ -31,6 +31,8 @@ class Selector implements Renderable
      */
     public const SELECTOR_VALIDATION_RX = '/
         ^(
+            # not whitespace only
+            (?!\\s*+$)
             (?:
                 # any sequence of valid unescaped characters, except quotes
                 [a-zA-Z0-9\\x{00A0}-\\x{FFFF}_^$|*=~\\[\\]()\\-\\s\\.:#+>,]++
@@ -57,7 +59,7 @@ class Selector implements Renderable
         /ux';
 
     /**
-     * @var string
+     * @var non-empty-string
      */
     private $selector;
 
@@ -73,6 +75,8 @@ public static function isValid(string $selector): bool
     }
 
     /**
+     * @param non-empty-string $selector
+     *
      * @throws \UnexpectedValueException if the selector is not valid
      */
     final public function __construct(string $selector)
@@ -83,7 +87,7 @@ final public function __construct(string $selector)
     /**
      * @param list<Comment> $comments
      *
-     * @return list<Component>
+     * @return non-empty-list<Component>
      *
      * @throws UnexpectedTokenException
      */
@@ -153,12 +157,17 @@ public static function parse(ParserState $parserState, array &$comments = []): s
         return new static($selectorString);
     }
 
+    /**
+     * @return non-empty-string
+     */
     public function getSelector(): string
     {
         return $this->selector;
     }
 
     /**
+     * @param non-empty-string $selector
+     *
      * @throws \UnexpectedValueException if the selector is not valid
      */
     public function setSelector(string $selector): void

tests/Unit/Property/SelectorTest.php

@@ -161,8 +161,11 @@ public function parseHandlesEvenNumberOfBackslashesBeforeQuote(): void
     public static function provideInvalidSelectors(): array
     {
         return [
-            // This is currently broken.
-            // 'empty string' => [''],
+            'empty string' => [''],
+            'space' => [' '],
+            'tab' => ["\t"],
+            'line feed' => ["\n"],
+            'carriage return' => ["\r"],
             'percent sign' => ['%'],
             // This is currently broken.
             // 'hash only' => ['#'],
@@ -176,16 +179,11 @@ public static function provideInvalidSelectors(): array
     }
 
     /**
-     * @return array<non-empty-string, array{0: string}>
+     * @return array<non-empty-string, array{0: non-empty-string}>
      */
     public static function provideInvalidSelectorsForParse(): array
     {
         return [
-            'empty string' => [''],
-            'space' => [' '],
-            'tab' => ["\t"],
-            'line feed' => ["\n"],
-            'carriage return' => ["\r"],
             'a `:not` missing the closing brace' => [':not(a'],
             'a `:not` missing the opening brace' => [':not a)'],
             'attribute value missing closing single quote' => ['a[href=\'#top]'],
@@ -315,16 +313,6 @@ public function parseExtractsTwoCommentsFromSelector(): void
         self::assertSame('comment2', $result[1]->getComment());
     }
 
-    /**
-     * @test
-     */
-    public function canConstructObjectWithEmptyState(): void
-    {
-        $subject = new Selector('');
-
-        self::assertSame('', $subject->getSelector());
-    }
-
     /**
      * @test
      *