Support natural

Author: herndlm

README.md

@@ -34,6 +34,7 @@ This extension specifies types of values passed to:
 * `Assert::stringNotEmpty`
 * `Assert::float`
 * `Assert::numeric`
+* `Assert::natural`
 * `Assert::integerish`
 * `Assert::boolean`
 * `Assert::scalar`

src/Type/WebMozartAssert/AssertTypeSpecifyingExtension.php

@@ -225,6 +225,18 @@ private static function getExpressionResolvers(): array
 						[$value]
 					);
 				},
+				'natural' => function (Scope $scope, Arg $value): \PhpParser\Node\Expr {
+					return new \PhpParser\Node\Expr\BinaryOp\BooleanAnd(
+						new \PhpParser\Node\Expr\FuncCall(
+							new \PhpParser\Node\Name('is_int'),
+							[$value]
+						),
+						new \PhpParser\Node\Expr\BinaryOp\GreaterOrEqual(
+							$value->value,
+							new \PhpParser\Node\Scalar\LNumber(0)
+						)
+					);
+				},
 				'boolean' => function (Scope $scope, Arg $value): \PhpParser\Node\Expr {
 					return new \PhpParser\Node\Expr\FuncCall(
 						new \PhpParser\Node\Name('is_bool'),

tests/Type/WebMozartAssert/data/type.php

@@ -18,4 +18,14 @@ public function positiveInteger($a): void
 		Assert::positiveInteger($b);
 		\PHPStan\Testing\assertType('*NEVER*', $b);
 	}
+
+	public function natural($a): void
+	{
+		Assert::natural($a);
+		\PHPStan\Testing\assertType('int<0, max>', $a);
+
+		$b = -1;
+		Assert::natural($b);
+		\PHPStan\Testing\assertType('*NEVER*', $b);
+	}
 }