Performance/CacheValueOverride: bug fix - false positive for PHP 8.1+ first class callable assignment

If a PHP 8.1+ first class callable is assigned to a variable, the assignment captures the callable, not the result of calling the callable.

This commit adds some dedicated code to handle this better and prevent the false positive.

Includes tests.

Author: jrfnl

WordPressVIPMinimum/Sniffs/Performance/CacheValueOverrideSniff.php

@@ -41,6 +41,27 @@ public function getGroups() {
 	 * @return void
 	 */
 	public function process_matched_token( $stackPtr, $group_name, $matched_content ) {
+		$openBracket = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $stackPtr + 1 ), null, true );
+		if ( $openBracket === false || isset( $this->tokens[ $openBracket ]['parenthesis_closer'] ) === false ) {
+			// Import use statement for function or parse error/live coding. Ignore.
+			return;
+		}
+
+		$closeBracket  = $this->tokens[ $openBracket ]['parenthesis_closer'];
+		$firstNonEmpty = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $openBracket + 1 ), null, true );
+		$nextNonEmpty  = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $firstNonEmpty + 1 ), null, true );
+		if ( $nextNonEmpty === false ) {
+			// Parse error/live coding. Ignore.
+			return;
+		}
+
+		if ( $this->tokens[ $firstNonEmpty ]['code'] === T_ELLIPSIS
+			&& $nextNonEmpty === $closeBracket
+		) {
+			// First class callable. Ignore.
+			return;
+		}
+
 		$variablePos = $this->isVariableAssignment( $stackPtr );
 		if ( $variablePos === false ) {
 			// Not a variable assignment.
@@ -50,12 +71,6 @@ public function process_matched_token( $stackPtr, $group_name, $matched_content
 		$variableToken = $this->tokens[ $variablePos ];
 		$variableName  = $variableToken['content'];
 
-		// Find the next non-empty token.
-		$openBracket = $this->phpcsFile->findNext( Tokens::$emptyTokens, $stackPtr + 1, null, true );
-
-		// Find the closing bracket.
-		$closeBracket = $this->tokens[ $openBracket ]['parenthesis_closer'];
-
 		$nextVariableOccurrence = $this->phpcsFile->findNext( T_VARIABLE, $closeBracket + 1, null, false, $variableName );
 
 		$rightAfterNextVariableOccurence = $this->phpcsFile->findNext( Tokens::$emptyTokens, $nextVariableOccurrence + 1, null, true, null, true );

WordPressVIPMinimum/Tests/Performance/CacheValueOverrideUnitTest.1.inc

@@ -82,3 +82,10 @@ function fqnFunctionCallBad() {
 	$shouldBeCaught = \wp_cache_get();
 	$shouldBeCaught = false; // Bad.
 }
+
+// Ignore PHP 8.1 first class callable.
+// Ignore as the assignment is not for the return value of the function, but for the callable.
+function firstClassCallable() {
+	$callable = wp_cache_get(...);
+	$callable = false; // OK.
+}

WordPressVIPMinimum/Tests/Performance/CacheValueOverrideUnitTest.2.inc

@@ -0,0 +1,5 @@
+<?php
+
+// Parse error/live coding test.
+// This should be the only test in the file.
+$liveCoding = wp_cache_get()