Added regression test

Author: staabm

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -926,4 +926,12 @@ public function testBug3747(): void
 		$this->analyse([__DIR__ . '/data/bug-3747.php'], []);
 	}
 
+	public function testBug8372(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->checkImplicitMixed = true;
+
+		$this->analyse([__DIR__ . '/data/bug-8372.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-8372.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types=1);
+
+namespace Bug8372;
+
+class Test
+{
+	/**
+	 * @param array<mixed> $path
+	 */
+	function test(string $method, array $path): void
+	{
+		if (!key_exists($method, $path)) {
+			return;
+		}
+
+		if (!is_array($path[$method])) {
+			return;
+		}
+
+		if (!key_exists('parameters', $path[$method])) {
+			$path[$method]['parameters'] = [];
+
+			$path[$method]['parameters'][] = 'foo';
+			$path[$method]['parameters'][] = 'bar';
+			$path[$method]['parameters'][] = 'baz';
+		}
+	}
+}