Squiz/NonExecutableCode: flag redundant return statements in closures too

A return statement which doesn't return a value at the end of a function body would be flagged as "not required" for named functions, but not so for anonymous functions.

Fixed now. Includes tests.

Author: jrfnl

src/Standards/Squiz/Sniffs/PHP/NonExecutableCodeSniff.php

@@ -122,7 +122,9 @@ public function process(File $phpcsFile, $stackPtr)
                     // then this return statement doesn't return anything
                     // and is not required anyway.
                     $owner = $tokens[$next]['scope_condition'];
-                    if ($tokens[$owner]['code'] === T_FUNCTION) {
+                    if ($tokens[$owner]['code'] === T_FUNCTION
+                        || $tokens[$owner]['code'] === T_CLOSURE
+                    ) {
                         $warning = 'Empty return statement not required here';
                         $phpcsFile->addWarning($warning, $stackPtr, 'ReturnNotRequired');
                         return;

src/Standards/Squiz/Tests/PHP/NonExecutableCodeUnitTest.1.inc

@@ -413,5 +413,11 @@ function returnNotRequiredIgnoreCommentsB()
     /*comment*/
 }
 
+$closure = function ()
+{
+    echo 'foo';
+    return; // This return should be flagged as not required.
+};
+
 // Intentional syntax error.
 return array_map(

src/Standards/Squiz/Tests/PHP/NonExecutableCodeUnitTest.php

@@ -84,6 +84,7 @@ public function getWarningList($testFile='')
                 396 => 1,
                 406 => 1,
                 412 => 1,
+                419 => 1,
             ];
             break;
         case 'NonExecutableCodeUnitTest.2.inc':