Fixed bug #3324 : PHPCS hangs processing some nested arrow functions inside a function call

Author: gsherwood

package.xml

@@ -36,6 +36,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
   - Fixed bug #3316 : Arrow function not tokenized correctly when using null in union type
   - Fixed bug #3317 : Problem with how phpcs handles ignored files when running in parallel
     -- Thanks to Emil Andersson for the patch
+  - Fixed bug #3324 : PHPCS hangs processing some nested arrow functions inside a function call
  </notes>
  <contents>
   <dir name="/">

src/Tokenizers/PHP.php

@@ -2355,6 +2355,16 @@ protected function processAdditional()
                                 break;
                             }
 
+                            if ($inTernary === false
+                                && isset($this->tokens[$scopeCloser]['scope_closer'], $this->tokens[$scopeCloser]['scope_condition']) === true
+                                && $scopeCloser === $this->tokens[$scopeCloser]['scope_closer']
+                                && $this->tokens[$this->tokens[$scopeCloser]['scope_condition']]['code'] === T_FN
+                            ) {
+                                // Found a nested arrow function that already has the closer set and is in
+                                // the same scope as us, so we can use its closer.
+                                break;
+                            }
+
                             if (isset($this->tokens[$scopeCloser]['scope_closer']) === true
                                 && $this->tokens[$scopeCloser]['code'] !== T_INLINE_ELSE
                                 && $this->tokens[$scopeCloser]['code'] !== T_END_HEREDOC

tests/Core/Tokenizer/BackfillFnTokenTest.inc

@@ -23,6 +23,9 @@ function fn() {}
 /* testNestedOuter */
 $fn = fn($x) => /* testNestedInner */ fn($y) => $x * $y + $z;
 
+/* testNestedSharedCloserOuter */
+$foo = foo(fn() => /* testNestedSharedCloserInner */ fn() => bar() === true);
+
 /* testFunctionCall */
 $extended = fn($c) => $callable($factory($c), $c);
 

tests/Core/Tokenizer/BackfillFnTokenTest.php

@@ -128,6 +128,41 @@ public function testNestedInner()
     }//end testNestedInner()
 
 
+    /**
+     * Test nested arrow functions with a shared closer.
+     *
+     * @covers PHP_CodeSniffer\Tokenizers\PHP::processAdditional
+     *
+     * @return void
+     */
+    public function testNestedSharedCloser()
+    {
+        $tokens = self::$phpcsFile->getTokens();
+
+        $token = $this->getTargetToken('/* testNestedSharedCloserOuter */', T_FN);
+        $this->backfillHelper($token);
+        $this->scopePositionTestHelper($token, 4, 20);
+
+        $token = $this->getTargetToken('/* testNestedSharedCloserInner */', T_FN);
+        $this->backfillHelper($token, true);
+
+        $expectedScopeOpener = ($token + 4);
+        $expectedScopeCloser = ($token + 12);
+
+        $this->assertSame($expectedScopeOpener, $tokens[$token]['scope_opener'], 'Scope opener for "inner" arrow function is not the arrow token');
+        $this->assertSame($expectedScopeCloser, $tokens[$token]['scope_closer'], 'Scope closer for "inner" arrow function is not the TRUE token');
+
+        $opener = $tokens[$token]['scope_opener'];
+        $this->assertSame($expectedScopeOpener, $tokens[$opener]['scope_opener'], 'Opener scope opener for "inner" arrow function is not the arrow token');
+        $this->assertSame($expectedScopeCloser, $tokens[$opener]['scope_closer'], 'Opener scope closer for "inner" arrow function is not the semicolon token');
+
+        $closer = $tokens[$token]['scope_closer'];
+        $this->assertSame(($token - 4), $tokens[$closer]['scope_opener'], 'Closer scope opener for "inner" arrow function is not the arrow token of the "outer" arrow function (shared scope closer)');
+        $this->assertSame($expectedScopeCloser, $tokens[$closer]['scope_closer'], 'Closer scope closer for "inner" arrow function is not the TRUE token');
+
+    }//end testNestedSharedCloser()
+
+
     /**
      * Test arrow functions that call functions.
      *