TypeSpecifier - understand preg_match() == 1 same way as === 1

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -1901,6 +1901,16 @@ public function resolveEqual(Expr\BinaryOp\Equal $expr, Scope $scope, TypeSpecif
 			) {
 				return $this->specifyTypesInCondition($scope, new Expr\BinaryOp\Identical($expr->left, $expr->right), $context, $rootExpr);
 			}
+
+			if (
+				$context->true()
+				&& $exprNode instanceof FuncCall
+				&& $exprNode->name instanceof Name
+				&& $exprNode->name->toLowerString() === 'preg_match'
+				&& (new ConstantIntegerType(1))->isSuperTypeOf($constantType)->yes()
+			) {
+				return $this->specifyTypesInCondition($scope, new Expr\BinaryOp\Identical($expr->left, $expr->right), $context, $rootExpr);
+			}
 		}
 
 		$leftType = $scope->getType($expr->left);

tests/PHPStan/Analyser/nsrt/preg_match_shapes_php74.php

@@ -195,3 +195,27 @@ function testPregMatchIdenticalToOneFalseyContextInverted(string $value): void {
 		assertType('array{string, string}', $matches);
 	}
 }
+
+function testPregMatchEqualToOne(string $value): void {
+	if (preg_match('/%env\((.*)\:.*\)%/U', $value, $matches) == 1) {
+		assertType('array{string, string}', $matches);
+	}
+}
+
+function testPregMatchEqualToOneFalseyContext(string $value): void {
+	if (!(preg_match('/%env\((.*)\:.*\)%/U', $value, $matches) != 1)) {
+		assertType('array{string, string}', $matches);
+	}
+}
+
+function testPregMatchEqualToOneInverted(string $value): void {
+	if (1 == preg_match('/%env\((.*)\:.*\)%/U', $value, $matches)) {
+		assertType('array{string, string}', $matches);
+	}
+}
+
+function testPregMatchEqualToOneFalseyContextInverted(string $value): void {
+	if (!(1 != preg_match('/%env\((.*)\:.*\)%/U', $value, $matches))) {
+		assertType('array{string, string}', $matches);
+	}
+}