SlevomatCodingStandard.Complexity.Cognitive: Support for arrow functions

Author: kukulich

SlevomatCodingStandard/Sniffs/Complexity/CognitiveSniff.php

@@ -22,6 +22,7 @@
 use const T_DO;
 use const T_ELSE;
 use const T_ELSEIF;
+use const T_FN;
 use const T_FOR;
 use const T_FOREACH;
 use const T_FUNCTION;
@@ -79,6 +80,7 @@ class CognitiveSniff implements Sniff
 	 * B3. Nesting increments
 	 */
 	private const NESTING_INCREMENTS = [
+		T_FN => T_FN,
 		T_CLOSURE => T_CLOSURE,
 		// increments, but does not receive
 		T_ELSEIF => T_ELSEIF,
@@ -127,10 +129,7 @@ class CognitiveSniff implements Sniff
 	 */
 	public function register(): array
 	{
-		return [
-			T_CLOSURE,
-			T_FUNCTION,
-		];
+		return TokenHelper::FUNCTION_TOKEN_CODES;
 	}
 
 	public function process(File $phpcsFile, int $stackPtr): void

tests/Sniffs/Complexity/CognitiveSniffTest.php

@@ -57,6 +57,12 @@ public static function dataProviderFiles(): array
 				'anonymous function',
 				19,
 			],
+			[
+				__DIR__ . '/data/cognitive/nesting4.php',
+				3,
+				'anonymous function',
+				19,
+			],
 			[
 				__DIR__ . '/data/cognitive/nestingContinueWithLabel.php',
 				3,

tests/Sniffs/Complexity/data/cognitive/nesting4.php

@@ -0,0 +1,34 @@
+<?php
+
+fn (ClassJavaType $classType) =>
+	if (true) { // +1
+		return $Symbols->unknownMethodSymbol();
+	}
+
+	$unknownFound = false;
+
+	$symbols = $classType->getSymbol()->members()->lookup(name);
+
+	foreach ($symbols as $symbol) { // +1
+		if ($overrideSymbol->isKind(MTH) // +2 (nesting = 1)
+			&& !$overrideSymbol->isStatic()) { // +1
+
+			if (canOverride($methodJavaSymbol)) { // +3 (nesting = 2)
+				$overriding = checkOverridingParameters($methodJavaSymbol, $classType);
+
+				if ($overriding === null) { // +4 (nesting = 3)
+					if (!$unknownFound) { // +5 (nesting = 4)
+						$unknownFound = true;
+					}
+				} elseif ($overriding) { // +1
+					return $methodJavaSymbol;
+				}
+			}
+		}
+	}
+
+	if ($unknownFound) { // +1
+		return $symbols->unknownMethodSymbol;
+	}
+
+	return null;