Fixed bug #3316 : Arrow function not tokenized correctly when using null in union type

Author: gsherwood

package.xml

@@ -31,6 +31,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
     -- Thanks to Juliette Reinders Folmer for the tests
   - Fixed bug #3296 : PSR2.ControlStructures.SwitchDeclaration takes phpcs:ignore as content of case body
   - Fixed bug #3303 : findStartOfStatement() doesn't work with T_OPEN_TAG_WITH_ECHO
+  - Fixed bug #3316 : Arrow function not tokenized correctly when using null in union type
  </notes>
  <contents>
   <dir name="/">

src/Tokenizers/PHP.php

@@ -2276,16 +2276,17 @@ protected function processAdditional()
                 if (isset($this->tokens[$x]) === true && $this->tokens[$x]['code'] === T_OPEN_PARENTHESIS) {
                     $ignore  = Util\Tokens::$emptyTokens;
                     $ignore += [
-                        T_STRING       => T_STRING,
                         T_ARRAY        => T_ARRAY,
+                        T_CALLABLE     => T_CALLABLE,
                         T_COLON        => T_COLON,
                         T_NAMESPACE    => T_NAMESPACE,
                         T_NS_SEPARATOR => T_NS_SEPARATOR,
+                        T_NULL         => T_NULL,
                         T_NULLABLE     => T_NULLABLE,
-                        T_CALLABLE     => T_CALLABLE,
                         T_PARENT       => T_PARENT,
                         T_SELF         => T_SELF,
                         T_STATIC       => T_STATIC,
+                        T_STRING       => T_STRING,
                         T_TYPE_UNION   => T_TYPE_UNION,
                     ];
 

tests/Core/Tokenizer/BackfillFnTokenTest.inc

@@ -93,6 +93,9 @@ $arrowWithUnionReturn = fn($param) : int|float => $param | 10;
 /* testTernary */
 $fn = fn($a) => $a ? /* testTernaryThen */ fn() : string => 'a' : /* testTernaryElse */ fn() : string => 'b';
 
+/* testTernaryWithTypes */
+$fn = fn(int|null $a) : array|null => $a ? null : [];
+
 function matchInArrow($x) {
     /* testWithMatchValue */
     $fn = fn($x) => match(true) {

tests/Core/Tokenizer/BackfillFnTokenTest.php

@@ -445,6 +445,24 @@ public function testTernary()
     }//end testTernary()
 
 
+    /**
+     * Test typed arrow functions used in ternary operators.
+     *
+     * @covers PHP_CodeSniffer\Tokenizers\PHP::processAdditional
+     *
+     * @return void
+     */
+    public function testTernaryWithTypes()
+    {
+        $tokens = self::$phpcsFile->getTokens();
+
+        $token = $this->getTargetToken('/* testTernaryWithTypes */', T_FN);
+        $this->backfillHelper($token);
+        $this->scopePositionTestHelper($token, 15, 27);
+
+    }//end testTernaryWithTypes()
+
+
     /**
      * Test arrow function returning a match control structure.
      *