Fix issue evaluating negated assertion

src/Psalm/Checker/Statements/Block/IfChecker.php

@@ -1531,10 +1531,6 @@ class IfChecker
             return $stmt;
         }
 
-        if ($stmt instanceof PhpParser\Node\Expr\BooleanNot) {
-            return self::getDefinitelyEvaluatedExpression($stmt->expr);
-        }
-
         return $stmt;
     }
 }

tests/ArgTest.php

@@ -47,6 +47,18 @@ class ArgTest extends TestCase
                     shuffle($a);
                     $a = [0, 1];',
             ],
+            'correctOrderValidation' => [
+                '<?php
+                    function getString(int $i) : string {
+                        return rand(0, 1) ? "hello" : "";
+                    }
+
+                    function takesInt(int $i) : void {}
+
+                    $i = rand(0, 10);
+
+                    if (!($i = getString($i))) {}',
+            ],
         ];
     }