Expand character ranges when trimming a numeric-string (#7013)

Author: SanderMuller

src/Type/Php/LtrimFunctionReturnTypeExtension.php

@@ -18,12 +18,17 @@
 use PHPStan\Type\TypeCombinator;
 use function count;
 use function ltrim;
-use function preg_match;
 
 #[AutowiredService]
 final class LtrimFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
 
+	public function __construct(
+		private TrimCharactersHelper $trimCharactersHelper,
+	)
+	{
+	}
+
 	public function isFunctionSupported(FunctionReflection $functionReflection): bool
 	{
 		return $functionReflection->getName() === 'ltrim';
@@ -72,7 +77,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 					}
 				} elseif ($trimConstantString->getValue() === '\\' && $string->isClassString()->yes()) {
 					$result[] = new ClassStringType();
-				} elseif (preg_match('/\d/', $trimConstantString->getValue()) === 0 && $string->isNumericString()->yes()) {
+				} elseif (!$this->trimCharactersHelper->containsDigit($trimConstantString->getValue()) && $string->isNumericString()->yes()) {
 					$result[] = new IntersectionType([new StringType(), new AccessoryNumericStringType()]);
 				} else {
 					return $defaultType;

src/Type/Php/TrimCharactersHelper.php

@@ -0,0 +1,44 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PHPStan\DependencyInjection\AutowiredService;
+use function ord;
+use function strlen;
+
+#[AutowiredService]
+final class TrimCharactersHelper
+{
+
+	/**
+	 * Reads the character list like PHP's php_charmask(): "a..z" stands for
+	 * every byte from "a" to "z", so "/..:" contains the digits.
+	 */
+	public function containsDigit(string $characters): bool
+	{
+		$length = strlen($characters);
+		for ($i = 0; $i < $length; $i++) {
+			$byte = ord($characters[$i]);
+			if (
+				$i + 3 < $length
+				&& $characters[$i + 1] === '.'
+				&& $characters[$i + 2] === '.'
+				&& ord($characters[$i + 3]) >= $byte
+			) {
+				if ($byte <= ord('9') && ord($characters[$i + 3]) >= ord('0')) {
+					return true;
+				}
+
+				$i += 3;
+				continue;
+			}
+
+			if ($byte >= ord('0') && $byte <= ord('9')) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+}

src/Type/Php/TrimFunctionDynamicReturnTypeExtension.php

@@ -17,14 +17,19 @@
 use PHPStan\Type\TypeCombinator;
 use function count;
 use function in_array;
-use function preg_match;
 use function rtrim;
 use function trim;
 
 #[AutowiredService]
 final class TrimFunctionDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
 
+	public function __construct(
+		private TrimCharactersHelper $trimCharactersHelper,
+	)
+	{
+	}
+
 	public function isFunctionSupported(FunctionReflection $functionReflection): bool
 	{
 		return in_array($functionReflection->getName(), ['trim', 'rtrim', 'chop'], true);
@@ -77,7 +82,7 @@ public function getTypeFromFunctionCall(
 							true,
 						);
 					}
-				} elseif (preg_match('/\d/', $trimConstantString->getValue()) === 0 && $stringType->isNumericString()->yes()) {
+				} elseif (!$this->trimCharactersHelper->containsDigit($trimConstantString->getValue()) && $stringType->isNumericString()->yes()) {
 					$result[] = new IntersectionType([new StringType(), new AccessoryNumericStringType()]);
 				} else {
 					return $defaultType;

tests/PHPStan/Analyser/nsrt/numeric-string-trim.php

@@ -28,6 +28,16 @@ public function doTrim(string $numericString, string $string): void
 		assertType('string', trim($numericString, '-0'));
 		assertType('string', ltrim($numericString, '-0'));
 		assertType('string', rtrim($numericString, '-0'));
+
+		assertType('string', trim($numericString, '/..:'));
+		assertType('string', ltrim($numericString, '/..:'));
+		assertType('string', rtrim($numericString, '/..:'));
+		assertType('string', chop($numericString, '/..:'));
+		assertType('string', trim($numericString, '!..~'));
+
+		assertType('numeric-string', trim($numericString, 'a..z'));
+		assertType('numeric-string', trim($numericString, '..:'));
+		assertType('numeric-string', trim($numericString, ':../'));
 	}
 
 }

tests/PHPStan/Type/Php/TrimCharactersHelperTest.php

@@ -0,0 +1,43 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+class TrimCharactersHelperTest extends TestCase
+{
+
+	public static function dataContainsDigit(): iterable
+	{
+		yield ['', false];
+		yield ['abc', false];
+		yield ['0', true];
+		yield ['9', true];
+		yield ['a5', true];
+		yield ['0..9', true];
+		yield ['9..9', true];
+		yield ['/..:', true];
+		yield ['!..~', true];
+		yield ['/..0', true];
+		yield ["\x00..\xff", true];
+		yield ['a..z', false];
+		yield [':..~', false];
+		yield [' ../', false];
+		yield ['a..z5', true];
+		yield ['...0', true];
+
+		// invalid ranges add no range, only the characters themselves
+		yield ['..:', false];
+		yield [':../', false];
+		yield ['a..', false];
+		yield ['5..', true];
+	}
+
+	#[DataProvider('dataContainsDigit')]
+	public function testContainsDigit(string $characters, bool $expected): void
+	{
+		$this->assertSame($expected, (new TrimCharactersHelper())->containsDigit($characters));
+	}
+
+}