Only use T_FN if it exists

Author: sirbrillig

VariableAnalysis/Lib/Helpers.php

@@ -149,8 +149,10 @@ public static function getFunctionIndexForFunctionArgument(File $phpcsFile, $sta
     $functionTokenTypes = [
       T_FUNCTION,
       T_CLOSURE,
-      T_FN, // TODO: cannot use this before PHP 7.4
     ];
+    if (defined('T_FN')) {
+      $functionTokenTypes[] = T_FN;
+    }
     if (!in_array($tokens[$functionPtr]['code'], $functionTokenTypes, true)) {
       return null;
     }
@@ -436,8 +438,10 @@ private static function getStartOfTokenScope(File $phpcsFile, $stackPtr) {
     $functionTokenTypes = [
       T_FUNCTION,
       T_CLOSURE,
-      T_FN, // TODO: cannot use this before PHP 7.4
     ];
+    if (defined('T_FN')) {
+      $functionTokenTypes[] = T_FN;
+    }
     foreach (array_reverse($conditions, true) as $scopePtr => $scopeCode) {
       if (in_array($scopeCode, $functionTokenTypes, true)) {
         return $scopePtr;
@@ -494,9 +498,12 @@ public static function isTokenInsideArrowFunctionBody(File $phpcsFile, $stackPtr
    * @return ?int
    */
   public static function getContainingArrowFunctionIndex(File $phpcsFile, $stackPtr) {
+    if (! defined('T_FN')) {
+      return null;
+    }
     $tokens = $phpcsFile->getTokens();
     $enclosingScopeIndex = self::findVariableScopeExceptArrowFunctions($phpcsFile, $stackPtr);
-    $arrowFunctionIndex = $phpcsFile->findPrevious([T_FN], $stackPtr - 1, $enclosingScopeIndex); // TODO: cannot use T_FN before PHP 7.4
+    $arrowFunctionIndex = $phpcsFile->findPrevious([T_FN], $stackPtr - 1, $enclosingScopeIndex);
     if (! is_int($arrowFunctionIndex)) {
       return null;
     }

VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php

@@ -118,7 +118,7 @@ class VariableAnalysisSniff implements Sniff {
    * @return (int|string)[]
    */
   public function register() {
-    return [
+    $types = [
       T_VARIABLE,
       T_DOUBLE_QUOTED_STRING,
       T_HEREDOC,
@@ -129,8 +129,11 @@ public function register() {
       T_COMMA,
       T_SEMICOLON,
       T_CLOSE_PARENTHESIS,
-      T_FN, // TODO: we can't use this before php 7.4 so we need to replace it somehow
     ];
+    if (defined('T_FN')) {
+      $types[] = T_FN;
+    }
+    return $types;
   }
 
   /**
@@ -165,8 +168,10 @@ public function process(File $phpcsFile, $stackPtr) {
     $scopeStartTokenTypes = [
       T_FUNCTION,
       T_CLOSURE,
-      T_FN, // TODO: we cannot use this before PHP 7.4
     ];
+    if (defined('T_FN')) {
+      $scopeStartTokenTypes[] = T_FN;
+    }
 
     $scopeIndexThisCloses = array_reduce($this->scopeStartIndices, function ($found, $index) use ($stackPtr, $tokens) {
       if ($stackPtr === $tokens[$index]['scope_closer']) {
@@ -279,7 +284,6 @@ protected function getVariableInfo($varName, $currScope) {
    * @return VariableInfo
    */
   protected function getOrCreateVariableInfo($varName, $currScope) {
-    // TODO: this needs to find the scope of an arrow function if we are inside one, which must also include the scope of its parent!
     $scopeInfo = $this->getOrCreateScopeInfo($currScope);
     if (!isset($scopeInfo->variables[$varName])) {
       Helpers::debug("creating a new variable for '{$varName}' in scope", $scopeInfo);
@@ -460,7 +464,6 @@ protected function isVariableUndefined($varName, $stackPtr, $currScope) {
     if (isset($varInfo->firstInitialized) && $varInfo->firstInitialized <= $stackPtr) {
       return false;
     }
-    // TODO: if the variable is in an arrow function body, also check the enclosing scope
     return true;
   }