Chained private methods should not be reported as unused

Author: kukulich

SlevomatCodingStandard/Sniffs/Classes/UnusedPrivateElementsSniff.php

@@ -177,6 +177,26 @@ public function process(\PHP_CodeSniffer\Files\File $phpcsFile, $classPointer)
 				if ($tokens[$variableTokenPointer]['code'] === T_VARIABLE && $tokens[$variableTokenPointer]['content'] === '$this') {
 					$findUsagesStartTokenPointer = $checkObjectOperatorUsage($tokenPointer);
 				} else {
+					$possibleThisTokenPointer = $tokenPointer - 1;
+					do {
+						$possibleThisTokenPointer = TokenHelper::findPreviousLocal($phpcsFile, T_VARIABLE, $possibleThisTokenPointer - 1);
+					} while ($possibleThisTokenPointer !== null && $tokens[$possibleThisTokenPointer]['content'] !== '$this');
+
+					if ($possibleThisTokenPointer !== null) {
+						$possibleMethodNamePointer = TokenHelper::findNextEffective($phpcsFile, $tokenPointer + 1);
+						if ($tokens[$possibleMethodNamePointer]['code'] === T_STRING) {
+							$possibleMethodCallPointer = TokenHelper::findNextEffective($phpcsFile, $possibleMethodNamePointer + 1);
+							if ($tokens[$possibleMethodCallPointer]['code'] === T_OPEN_PARENTHESIS) {
+								$methodName = $tokens[$possibleMethodNamePointer]['content'];
+								if (isset($reportedMethods[$methodName])) {
+									unset($reportedMethods[$methodName]);
+									$findUsagesStartTokenPointer = $possibleMethodCallPointer + 1;
+									continue;
+								}
+							}
+						}
+					}
+
 					$findUsagesStartTokenPointer = $tokenPointer + 1;
 				}
 			} elseif ($token['code'] === T_DOUBLE_COLON) {

tests/Sniffs/Classes/UnusedPrivateElementsSniffTest.php

@@ -113,6 +113,12 @@ public function testClassWithPrivateElementsUsedOnStaticInstance()
 		$this->assertNoSniffErrorInFile($report);
 	}
 
+	public function testClassWithChainedPrivateMethods()
+	{
+		$report = $this->checkFile(__DIR__ . '/data/classWithChainedPrivateMethods.php');
+		$this->assertNoSniffErrorInFile($report);
+	}
+
 	public function testClassWithConstants()
 	{
 		$resultFile = $this->checkFile(__DIR__ . '/data/classWithConstants.php');

tests/Sniffs/Classes/data/classWithChainedPrivateMethods.php

@@ -0,0 +1,30 @@
+<?php
+
+class Test
+{
+
+	public function __construct()
+	{
+		$this
+			->testMethod1()
+			->testMethod2()
+			->testMethod3()
+		;
+	}
+
+	private function testMethod1()
+	{
+		return $this;
+	}
+
+	private function testMethod2()
+	{
+		return $this;
+	}
+
+	private function testMethod3()
+	{
+		return $this;
+	}
+
+}