Implemented mixed primitive (#19)

Author: emnlmn

.gitignore

@@ -8,3 +8,5 @@ composer.phar
 .*.cache
 composer.lock
 build/
+
+.php_cs.dist

docker-compose.override.yml.dist

@@ -0,0 +1,14 @@
+version: "3.8"
+
+services:
+  php:
+    volumes:
+    - local:/home/dev/lib
+
+volumes:
+  local:
+    driver: local
+    driver_opts:
+      type: nfs
+      o: addr=host.docker.internal,rw,nolock,hard,nointr,nfsvers=3,rsize=32768,wsize=32768
+      device: ":$PWD"

src/Codecs.php

@@ -14,6 +14,7 @@
 use Facile\PhpCodec\Internal\Primitives\BoolType;
 use Facile\PhpCodec\Internal\Primitives\FloatType;
 use Facile\PhpCodec\Internal\Primitives\IntType;
+use Facile\PhpCodec\Internal\Primitives\MixedDecoder;
 use Facile\PhpCodec\Internal\Primitives\NullType;
 use Facile\PhpCodec\Internal\Primitives\StringType;
 use Facile\PhpCodec\Internal\Primitives\UndefinedDecoder;
@@ -216,4 +217,14 @@ public static function undefined($default = null): Codec
     {
         return self::fromDecoder(new UndefinedDecoder($default));
     }
+
+    /**
+     * @template U of mixed
+     *
+     * @return Codec<U, U, U>
+     */
+    public static function mixed(): Codec
+    {
+        return self::fromDecoder(new MixedDecoder());
+    }
 }

src/Internal/Primitives/MixedDecoder.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Facile\PhpCodec\Internal\Primitives;
+
+use Facile\PhpCodec\Decoder;
+use function Facile\PhpCodec\Internal\standardDecode;
+use Facile\PhpCodec\Validation\Context;
+use Facile\PhpCodec\Validation\Validation;
+
+/**
+ * @template U of mixed
+ * @implements Decoder<U, U>
+ */
+class MixedDecoder implements Decoder
+{
+    public function validate($i, Context $context): Validation
+    {
+        return Validation::success($i);
+    }
+
+    public function decode($i): Validation
+    {
+        return standardDecode($this, $i);
+    }
+
+    public function getName(): string
+    {
+        return 'mixed';
+    }
+}

tests/unit/Internal/Primitives/MixedTypeTest.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Facile\PhpCodec\Internal\Primitives;
+
+use Eris\TestTrait;
+use Facile\PhpCodec\Codecs;
+use Tests\Facile\PhpCodec\BaseTestCase;
+use Tests\Facile\PhpCodec\GeneratorUtils;
+
+class MixedTypeTest extends BaseTestCase
+{
+    use TestTrait;
+
+    public function testLaws(): void
+    {
+        $this
+            ->forAll(
+                GeneratorUtils::scalar(),
+                GeneratorUtils::scalar()
+            )
+            ->then(self::codecLaws(Codecs::mixed()));
+    }
+}