reproduce bug 1396

Author: clxmstaab

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1335,6 +1335,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-9293.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/nullsafe-vs-scalar.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8517.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-1396.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-1396.php

@@ -0,0 +1,30 @@
+<?php declare(strict_types = 1);
+
+namespace Bug1396;
+
+use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\ConstantScalarType;
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	public function doFoo(
+		ConstantScalarType $constantType
+	): SpecifiedTypes
+	{
+		assertType('bool|float|int|string|null', $constantType->getValue());
+
+		if ($constantType->getValue() === null) {
+			return new SpecifiedTypes();
+		}
+
+		assertType('bool|float|int|string', $constantType->getValue());
+
+		if (
+			$constantType instanceof ConstantStringType
+		) {
+			assertType('string', $constantType->getValue());
+		}
+		assertType('bool|float|int|string', $constantType->getValue());
+	}
+}