[BUGFIX] Allow commas in attributes in setSelectors

CHANGELOG.md

@@ -24,6 +24,8 @@ Please also have a look at our
 
 ### Fixed
 
+- Support attribute selectors with values containing commas in
+  `DeclarationBlock::setSelectors()` (#1419)
 - Allow `removeDeclarationBlockBySelector()` to be order-insensitve (#1406)
 - Fix parsing of `calc` expressions when a newline immediately precedes or
   follows a `+` or `-` operator (#1399)

src/RuleSet/DeclarationBlock.php

@@ -20,6 +20,7 @@
 use Sabberworm\CSS\Property\KeyframeSelector;
 use Sabberworm\CSS\Property\Selector;
 use Sabberworm\CSS\Rule\Rule;
+use Sabberworm\CSS\Settings;
 
 /**
  * This class represents a `RuleSet` constrained by a `Selector`.
@@ -98,7 +99,25 @@ public function setSelectors($selectors, ?CSSList $list = null): void
         if (\is_array($selectors)) {
             $selectorsToSet = $selectors;
         } else {
-            $selectorsToSet = \explode(',', $selectors);
+            // A string of comma-separated selectors requires parsing.
+            // Parse as if it's the opening part of a rule.
+            try {
+                $parserState = new ParserState($selectors . '{', Settings::create());
+                $selectorsToSet = self::parseSelectors($parserState);
+                $parserState->consume('{'); // throw exception if this is not next
+                if (!$parserState->isEnd()) {
+                    throw new UnexpectedTokenException('EOF', 'more');
+                }
+            } catch (UnexpectedTokenException $exception) {
+                // The exception message from parsing may refer to the faux `{` block start token,
+                // which would be confusing.
+                // Rethrow with a more useful message, that also includes the selector(s) string that was passed.
+                throw new UnexpectedTokenException(
+                    'Selector(s) string is not valid.',
+                    $selectors,
+                    'custom'
+                );
+            }
         }
 
         // Convert all items to a `Selector` if not already
@@ -261,7 +280,7 @@ public function render(OutputFormat $outputFormat): string
      *
      * @throws UnexpectedTokenException
      */
-    private static function parseSelectors(ParserState $parserState, array &$comments): array
+    private static function parseSelectors(ParserState $parserState, array &$comments = []): array
     {
         $selectors = [];
         $selectorParts = [];

tests/Unit/RuleSet/DeclarationBlockTest.php

@@ -8,6 +8,7 @@
 use Sabberworm\CSS\CSSElement;
 use Sabberworm\CSS\CSSList\CSSListItem;
 use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Property\Selector;
 use Sabberworm\CSS\Rule\Rule;
@@ -293,4 +294,73 @@ public function setSelectorsIgnoresKeys(): void
 
         self::assertSame([0, 1], \array_keys($result));
     }
+
+    /**
+     * @test
+     *
+     * @param non-empty-string $selector
+     *
+     * @dataProvider provideSelector
+     */
+    public function setSelectorsSetsSingleSelectorProvidedAsString(string $selector): void
+    {
+        $subject = new DeclarationBlock();
+
+        $subject->setSelectors($selector);
+
+        $result = $subject->getSelectors();
+        self::assertSame([$selector], self::getSelectorsAsStrings($subject));
+    }
+
+    /**
+     * @test
+     *
+     * @param non-empty-string $firstSelector
+     * @param non-empty-string $secondSelector
+     *
+     * @dataProvider provideTwoSelectors
+     */
+    public function setSelectorsSetsTwoCommaSeparatedSelectorsProvidedAsString(
+        string $firstSelector,
+        string $secondSelector
+    ): void {
+        $joinedSelectors = $firstSelector . ', ' . $secondSelector;
+        $subject = new DeclarationBlock();
+
+        $subject->setSelectors($joinedSelectors);
+
+        $result = $subject->getSelectors();
+        self::assertSame([$firstSelector, $secondSelector], self::getSelectorsAsStrings($subject));
+    }
+
+    /**
+     * Provides selectors that would be parsed without error in the context of full CSS, but are nonetheless invalid.
+     *
+     * @return array<non-empty-string, array{0: non-empty-string}>
+     */
+    public static function provideInvalidStandaloneSelector(): array
+    {
+        return [
+            'rogue `{`' => ['a { b'],
+            'rogue `}`' => ['a } b'],
+        ];
+    }
+
+    /**
+     * @test
+     *
+     * @param non-empty-string $selector
+     *
+     * @dataProvider provideInvalidSelector
+     * @dataProvider provideInvalidStandaloneSelector
+     */
+    public function setSelectorsThrowsExceptionWithInvalidSelector(string $selector): void
+    {
+        $this->expectException(UnexpectedTokenException::class);
+        $this->expectExceptionMessageMatches('/^Selector\\(s\\) string is not valid. /');
+
+        $subject = new DeclarationBlock();
+
+        $subject->setSelectors($selector);
+    }
 }