added regression test

Author: staabm

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php

@@ -1121,4 +1121,15 @@ public function testBug7773(): void
 		$this->analyse([__DIR__ . '/data/bug-7773.php'], []);
 	}
 
+	public function testPr4375(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/pr-4375.php'], [
+			[
+				'Call to function array_key_exists() with string and array<string, *NEVER*> will always evaluate to false.',
+				14,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/pr-4375.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace PR2375;
+
+final class Foo
+{
+	public function processNode(): array
+	{
+		$methods = [];
+		foreach ($this->get() as $collected) {
+			foreach ($collected as [$className, $methodName, $classDisplayName]) {
+				$className = strtolower($className);
+
+				if (!array_key_exists($className, $methods)) {
+					$methods[$className] = [];
+				}
+				$methods[$className][strtolower($methodName)] = $classDisplayName . '::' . $methodName;
+			}
+		}
+
+		return [];
+	}
+
+	private function get(): array {
+		return [];
+	}
+}