More precise types for preg_match greater than 0

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -242,11 +242,11 @@ public function specifyTypesInCondition(
 				$expr->left instanceof FuncCall
 				&& count($expr->left->getArgs()) >= 1
 				&& $expr->left->name instanceof Name
-				&& in_array(strtolower((string) $expr->left->name), ['count', 'sizeof', 'strlen', 'mb_strlen'], true)
+				&& in_array(strtolower((string) $expr->left->name), ['count', 'sizeof', 'strlen', 'mb_strlen', 'preg_match'], true)
 				&& (
 					!$expr->right instanceof FuncCall
 					|| !$expr->right->name instanceof Name
-					|| !in_array(strtolower((string) $expr->right->name), ['count', 'sizeof', 'strlen', 'mb_strlen'], true)
+					|| !in_array(strtolower((string) $expr->right->name), ['count', 'sizeof', 'strlen', 'mb_strlen', 'preg_match'], true)
 				)
 			) {
 				$inverseOperator = $expr instanceof Node\Expr\BinaryOp\Smaller
@@ -336,6 +336,22 @@ public function specifyTypesInCondition(
 				}
 			}
 
+			if (
+				!$context->null()
+				&& $expr->right instanceof FuncCall
+				&& count($expr->right->getArgs()) === 3
+				&& $expr->right->name instanceof Name
+				&& in_array(strtolower((string) $expr->right->name), ['preg_match'], true)
+				&& IntegerRangeType::fromInterval(0, null)->isSuperTypeOf($leftType)->yes()
+			) {
+				return $this->specifyTypesInCondition(
+					$scope,
+					new Expr\BinaryOp\NotIdentical($expr->right, new ConstFetch(new Name('false'))),
+					$context,
+					$rootExpr,
+				);
+			}
+
 			if (
 				!$context->null()
 				&& $expr->right instanceof FuncCall

tests/PHPStan/Analyser/nsrt/bug-11293.php

@@ -0,0 +1,51 @@
+<?php // lint >= 7.4
+
+namespace Bug11293;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	public function sayHello(string $s): void
+	{
+		if (preg_match('/data-(\d{6})\.json$/', $s, $matches) > 0) {
+			assertType('array{string, non-falsy-string&numeric-string}', $matches);
+		}
+	}
+
+	public function sayHello2(string $s): void
+	{
+		if (preg_match('/data-(\d{6})\.json$/', $s, $matches) === 1) {
+			assertType('array{string, non-falsy-string&numeric-string}', $matches);
+		}
+	}
+
+	public function sayHello3(string $s): void
+	{
+		if (preg_match('/data-(\d{6})\.json$/', $s, $matches) >= 1) {
+			assertType('array{string, non-falsy-string&numeric-string}', $matches);
+		}
+	}
+
+	public function sayHello4(string $s): void
+	{
+		if (preg_match('/data-(\d{6})\.json$/', $s, $matches) <= 0) {
+			assertType('array{}', $matches);
+
+			return;
+		}
+
+		assertType('array{string, non-falsy-string&numeric-string}', $matches);
+	}
+
+	public function sayHello5(string $s): void
+	{
+		if (preg_match('/data-(\d{6})\.json$/', $s, $matches) < 1) {
+			assertType('array{}', $matches);
+
+			return;
+		}
+
+		assertType('array{string, non-falsy-string&numeric-string}', $matches);
+	}
+}