RegexArrayShapeMatcher - more precise subject types

Author: staabm

src/Type/Php/RegexArrayShapeMatcher.php

@@ -114,6 +114,15 @@ private function matchRegex(string $regex, ?int $flags, TrinaryLogic $wasMatched
 		}
 		[$groupList, $markVerbs] = $parseResult;
 
+		if ($groupList === [] && $markVerbs === []) {
+			$rawRegex = $this->regexExpressionHelper->removeDelimitersAndModifiers($regex);
+			$type = $this->matchRegex('{('.$rawRegex.')}', $flags, $wasMatched, $matchesAll);
+			if ($type === null) {
+				return null;
+			}
+			return $type->shiftArray();
+		}
+
 		$regexGroupList = new RegexGroupList($groupList);
 		$trailingOptionals = $regexGroupList->countTrailingOptionals();
 		$onlyOptionalTopLevelGroup = $regexGroupList->getOnlyOptionalTopLevelGroup();

test.php

@@ -0,0 +1,53 @@
+<?php
+
+use function PHPStan\Testing\assertType;
+
+/** @return non-empty-string|null */
+function bug12749(string $str): ?string
+{
+	if (preg_match('/[A-Z]/', $str, $match)) {
+		assertType('array{non-empty-string}', $match);
+		return $match[0];
+	}
+	return null;
+}
+
+/** @return non-falsy-string|null */
+function doFoo(string $str): ?string
+{
+	if (preg_match('/[A-Z]{2,}/', $str, $match)) {
+		assertType('array{non-falsy-string}', $match);
+		return $match[0];
+	}
+	return null;
+}
+
+/** @return non-falsy-string|null */
+function doBar(string $str): ?string
+{
+	if (preg_match('/[0-9][A-Z]/', $str, $match)) {
+		assertType('array{non-falsy-string}', $match);
+		return $match[0];
+	}
+	return null;
+}
+
+/** @return non-empty-string|null */
+function doFooBar(string $str): ?string
+{
+	if (preg_match('/[0-9][A-Z]?/', $str, $match)) {
+		assertType('array{non-empty-string}', $match);
+		return $match[0];
+	}
+	return null;
+}
+
+/** @return non-falsy-string|null */
+function doFooBar2(string $str): ?string
+{
+	if (preg_match('/[0-9]?[A-Z]/', $str, $match)) {
+		assertType('array{non-falsy-string}', $match);
+		return $match[0];
+	}
+	return null;
+}

tests/PHPStan/Analyser/nsrt/preg_match_shapes.php

@@ -960,3 +960,11 @@ function bug11744(string $string): void
 	}
 	assertType('array{0: string, 1: non-empty-string, 2?: non-falsy-string}', $matches);
 }
+
+/** @return non-empty-string|null */
+function bug12749(string $str): void
+{
+	if (preg_match('/[A-Z]/', $str, $match)) {
+		assertType('string', $match);
+	}
+}