Add support for the mixed type

CHANGELOG.md

@@ -1,7 +1,9 @@
 Version 4.4.1-dev
 -----------------
 
-Nothing yet.
+### Added
+
+* Added support for the mixed type
 
 Version 4.4.0 (2020-04-10)
 --------------------------

lib/PhpParser/BuilderHelpers.php

@@ -183,7 +183,7 @@ final class BuilderHelpers
         }
 
         $builtinTypes = [
-            'array', 'callable', 'string', 'int', 'float', 'bool', 'iterable', 'void', 'object'
+            'array', 'callable', 'string', 'int', 'float', 'bool', 'iterable', 'void', 'object', 'mixed'
         ];
 
         $lowerType = strtolower($type);
@@ -197,6 +197,10 @@ final class BuilderHelpers
             throw new \LogicException('void type cannot be nullable');
         }
 
+        if ($nullable && (string) $type === 'mixed') {
+            throw new \LogicException('mixed type cannot be nullable');
+        }
+
         return $nullable ? new NullableType($type) : $type;
     }
 

lib/PhpParser/ParserAbstract.php

@@ -648,7 +648,7 @@ abstract class ParserAbstract implements Parser
     }
 
     protected function handleBuiltinTypes(Name $name) {
-        $scalarTypes = [
+        $builtinTypes = [
             'bool'     => true,
             'int'      => true,
             'float'    => true,
@@ -658,6 +658,7 @@ abstract class ParserAbstract implements Parser
             'object'   => true,
             'null'     => true,
             'false'    => true,
+            'mixed'    => true,
         ];
 
         if (!$name->isUnqualified()) {
@@ -665,7 +666,7 @@ abstract class ParserAbstract implements Parser
         }
 
         $lowerName = $name->toLowerString();
-        if (!isset($scalarTypes[$lowerName])) {
+        if (!isset($builtinTypes[$lowerName])) {
             return $name;
         }
 

test/PhpParser/Builder/ParamTest.php

@@ -113,6 +113,7 @@ class ParamTest extends \PHPUnit\Framework\TestCase
             ['object', new Node\Identifier('object')],
             ['Array', new Node\Identifier('array')],
             ['CALLABLE', new Node\Identifier('callable')],
+            ['mixed', new Node\Identifier('mixed')],
             ['Some\Class', new Node\Name('Some\Class')],
             ['\Foo', new Node\Name\FullyQualified('Foo')],
             ['self', new Node\Name('self')],

test/code/parser/stmt/function/builtinTypeDeclarations.test

@@ -1,7 +1,7 @@
 Scalar type declarations
 -----
 <?php
-function test(bool $a, Int $b, FLOAT $c, StRiNg $d, iterable $e, object $f) : void {}
+function test(bool $a, Int $b, FLOAT $c, StRiNg $d, iterable $e, object $f, mixed $g) : void {}
 -----
 !!php7
 array(
@@ -77,6 +77,17 @@ array(
                 )
                 default: null
             )
+            6: Param(
+                type: Identifier(
+                    name: mixed
+                )
+                byRef: false
+                variadic: false
+                var: Expr_Variable(
+                    name: g
+                )
+                default: null
+            )
         )
         returnType: Identifier(
             name: void