Try to process scope close for arrow functions

Author: sirbrillig

VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php

@@ -11,6 +11,7 @@
 use PHP_CodeSniffer\Files\File;
 use PHP_CodeSniffer\Util\Tokens;
 use PHPCSUtils\Utils\Lists;
+use PHPCSUtils\Utils\FunctionDeclarations;
 
 class VariableAnalysisSniff implements Sniff {
   /**
@@ -117,6 +118,7 @@ public function register() {
       T_HEREDOC,
       T_CLOSE_CURLY_BRACKET,
       T_STRING,
+      T_FN, // TODO: we can't use this before php 7.4 so we need to replace it somehow
     ];
   }
 
@@ -175,7 +177,11 @@ public function process(File $phpcsFile, $stackPtr) {
       $this->processScopeClose($phpcsFile, $token['scope_condition']);
       return;
     }
-    // TODO: process scope close for arrow functions (how do we know where the scope ends?)
+    if (($token['type'] === 'T_FN') && isset($token['scope_closer'])) {
+      Helpers::debug('found arrow function', $token);
+      $this->processScopeClose($phpcsFile, $token['scope_closer'] - 1);
+      return;
+    }
   }
 
   /**
@@ -248,9 +254,10 @@ 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 new variable for', $varName, 'in scope', $scopeInfo);
+      Helpers::debug("creating a new variable for '{$varName}' in scope", $scopeInfo);
       $scopeInfo->variables[$varName] = new VariableInfo($varName);
       $validUnusedVariableNames = (empty($this->validUnusedVariableNames))
         ? []
@@ -268,7 +275,7 @@ protected function getOrCreateVariableInfo($varName, $currScope) {
         $scopeInfo->variables[$varName]->ignoreUndefined = true;
       }
     }
-    Helpers::debug('scope for', $varName, 'in scope', $currScope, 'is', $scopeInfo);
+    Helpers::debug("scope for '{$varName}' is now", $scopeInfo);
     return $scopeInfo->variables[$varName];
   }
 
@@ -334,7 +341,7 @@ protected function markVariableDeclaration(
     $currScope,
     $permitMatchingRedeclaration = false
   ) {
-    Helpers::debug('marking variable declared', $varName, $currScope);
+    Helpers::debug("marking variable '{$varName}' declared in scope starting at token", $currScope);
     $varInfo = $this->getOrCreateVariableInfo($varName, $currScope);
     if (isset($varInfo->scopeType)) {
       if (($permitMatchingRedeclaration === false) || ($varInfo->scopeType !== $scopeType)) {
@@ -359,11 +366,11 @@ protected function markVariableDeclaration(
       $varInfo->typeHint = $typeHint;
     }
     if (isset($varInfo->firstDeclared) && ($varInfo->firstDeclared <= $stackPtr)) {
-    Helpers::debug('variable was already marked declared', $varName, $varInfo);
+      Helpers::debug("variable '{$varName}' was already marked declared", $varInfo);
       return;
     }
     $varInfo->firstDeclared = $stackPtr;
-    Helpers::debug('variable marked declared', $varName, $varInfo);
+    Helpers::debug("variable '{$varName}' marked declared", $varInfo);
   }
 
   /**
@@ -433,7 +440,6 @@ protected function isVariableUndefined($varName, $stackPtr, $currScope) {
    */
   protected function markVariableReadAndWarnIfUndefined($phpcsFile, $varName, $stackPtr, $currScope) {
     $this->markVariableRead($varName, $stackPtr, $currScope);
-    // TODO: this is not finding variables defined in an arrow function scope
     if ($this->isVariableUndefined($varName, $stackPtr, $currScope) === true) {
       Helpers::debug("variable $varName looks undefined");
       $phpcsFile->addWarning(
@@ -472,7 +478,7 @@ protected function markAllVariablesRead(File $phpcsFile, $stackPtr) {
    *
    * @return bool
    */
-  protected function checkForFunctionPrototype(File $phpcsFile, $stackPtr, $varName, $currScope) {
+  protected function checkForFunctionDefinition(File $phpcsFile, $stackPtr, $varName, $currScope) {
     $tokens = $phpcsFile->getTokens();
 
     // Are we a function or closure parameter?
@@ -489,7 +495,7 @@ protected function checkForFunctionPrototype(File $phpcsFile, $stackPtr, $varNam
       (is_int($functionPtr))
       && (
         ($tokens[$functionPtr]['code'] === T_FUNCTION)
-        || ($tokens[$functionPtr]['code'] === T_FN) // TODO: we can't use this because it's only in php7.4, use \PHPCSUtils\Utils\isArrowFunction instead
+        || (FunctionDeclarations::isArrowFunction($phpcsFile, $functionPtr))
         || ($tokens[$functionPtr]['code'] === T_CLOSURE)
       )
     ) {
@@ -512,7 +518,7 @@ protected function checkForFunctionPrototype(File $phpcsFile, $stackPtr, $varNam
       $this->markVariableRead($varName, $stackPtr, $currScope);
       if ($this->isVariableUndefined($varName, $stackPtr, $currScope) === true) {
         // We haven't been defined by this point.
-        Helpers::debug("variable $varName in function prototype looks undefined");
+        Helpers::debug("variable '{$varName}' in function definition looks undefined");
         $phpcsFile->addWarning("Variable %s is undefined.", $stackPtr, 'UndefinedVariable', ["\${$varName}"]);
         return true;
       }
@@ -1146,7 +1152,7 @@ protected function processVariable(File $phpcsFile, $stackPtr) {
     $token  = $tokens[$stackPtr];
 
     $varName = Helpers::normalizeVarName($token['content']);
-    Helpers::debug('examining token ' . $varName);
+    Helpers::debug("examining token for variable '{$varName}'", $token);
     $currScope = Helpers::findVariableScope($phpcsFile, $stackPtr);
     if ($currScope === null) {
       Helpers::debug('no scope found');
@@ -1180,8 +1186,8 @@ protected function processVariable(File $phpcsFile, $stackPtr) {
     }
 
     // Are we a function or closure parameter?
-    if ($this->checkForFunctionPrototype($phpcsFile, $stackPtr, $varName, $currScope)) {
-      Helpers::debug('found function prototype');
+    if ($this->checkForFunctionDefinition($phpcsFile, $stackPtr, $varName, $currScope)) {
+      Helpers::debug('found function definition');
       return;
     }