Added support for omitting parentheses in Serializer

Author: JoshyPHP

src/Serializer.php

@@ -44,9 +44,10 @@ public function __construct(OutputInterface $output, MetaCharacters $meta, Escap
 	* Serialize given strings into a regular expression
 	*
 	* @param  array[] $strings
+	* @param  bool    $groupAlternations Whether alternations should be parenthesized into a group
 	* @return string
 	*/
-	public function serializeStrings(array $strings): string
+	public function serializeStrings(array $strings, bool $groupAlternations = true): string
 	{
 		$info         = $this->analyzeStrings($strings);
 		$alternations = array_map([$this, 'serializeString'], $info['strings']);
@@ -57,7 +58,7 @@ public function serializeStrings(array $strings): string
 		}
 
 		$expr = implode('|', $alternations);
-		if ($this->needsParentheses($info))
+		if ($this->needsParentheses($info, $groupAlternations))
 		{
 			$expr = '(?:' . $expr . ')';
 		}
@@ -189,11 +190,13 @@ protected function isSingleQuantifiableString(array $strings): bool
 	* Test whether an expression needs parentheses based on the strings info
 	*
 	* @param  array $info
+	* @param  bool  $groupAlternations Whether alternations should be parenthesized into a group
 	* @return bool
 	*/
-	protected function needsParentheses(array $info): bool
+	protected function needsParentheses(array $info, bool $groupAlternations): bool
 	{
-		return ($info['alternationsCount'] > 1 || ($info['quantifier'] && !$this->isQuantifiable($info)));
+		return (($groupAlternations  && $info['alternationsCount'] > 1)
+		     || ($info['quantifier'] && !$this->isQuantifiable($info)));
 	}
 
 	/**

tests/SerializerTest.php

@@ -17,10 +17,16 @@ class SerializerTest extends TestCase
 	/**
 	* @dataProvider getSerializerTests
 	*/
-	public function test($original, $expected)
+	public function test($original, $expected, bool $groupAlternations = null)
 	{
+		$args = [$original];
+		if (isset($groupAlternations))
+		{
+			$args[] = $groupAlternations;
+		}
+
 		$serializer = new Serializer(new Output, new MetaCharacters(new Input), new Escaper);
-		$this->assertSame($expected, $serializer->serializeStrings($original, false));
+		$this->assertSame($expected, $serializer->serializeStrings(...$args));
 	}
 
 	public function getSerializerTests()
@@ -130,6 +136,31 @@ public function getSerializerTests()
 				],
 				'[a-e]'
 			],
+			[
+				[
+					[97, 97],
+					[98, 98]
+				],
+				'(?:aa|bb)',
+				true
+			],
+			[
+				[
+					[97, 97],
+					[98, 98]
+				],
+				'aa|bb',
+				false
+			],
+			[
+				[
+					[],
+					[97, 97],
+					[98, 98]
+				],
+				'(?:aa|bb)?',
+				false
+			],
 		];
 	}
 }