fix ref function to work properly with array syntax

src/Exception/NoAccessException.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * Copyright 2018 Kacper Donat
+ *
+ * @author Kacper "Kadet" Donat <kacper@kadet.net>
+ *
+ * Full license available in separate LICENSE file
+ */
+
+namespace Kadet\Functional\Exception;
+
+class NoAccessException extends FunctionalException
+{
+}

src/Transforms/index.php

@@ -7,4 +7,4 @@
  * Full license available in separate LICENSE file
  */
 
-
+require_once 'objects.php';

src/functions.php

@@ -2,6 +2,7 @@
 
 namespace Kadet\Functional;
 
+use Kadet\Functional\Exception\NoAccessException;
 use Kadet\Functional\Predicate\AllOfPredicate;
 use Kadet\Functional\Predicate\AnyOfPredicate;
 use Kadet\Functional\Predicate\ClosurePredicate;
@@ -32,8 +33,24 @@ function predicate($predicate): Predicate
     }
 }
 
-function ref(callable $callable)
+function ref($callable)
 {
+    if (is_array($callable)) {
+        list($object, $method) = $callable;
+        $reflection = new \ReflectionObject($object);
+        $method     = $reflection->getMethod($method);
+
+        if (!$method->isPublic()) {
+            $class = debug_backtrace()[1]['class'] ?? null;
+
+            if ($reflection->name !== $class) {
+                throw new NoAccessException(sprintf('Method "%s" can only be accessed from inside of object.', $method->name));
+            }
+        }
+
+        return $method->getClosure($object);
+    }
+
     return \Closure::fromCallable($callable);
 }
 
@@ -100,7 +117,7 @@ function reflect(callable $callable): \ReflectionFunction
         case $callable instanceof Decorator:
             return new ReflectionDecoratedFunction($callable->getDecorated());
         default:
-            return new \ReflectionFunction($callable);
+            return new \ReflectionFunction(ref($callable));
     }
 }
 

tests/RandomTest.php

@@ -0,0 +1,57 @@
+<?php
+
+use function Kadet\Functional\apply;
+use function Kadet\Functional\ref;
+
+/**
+ * Copyright 2018 Kacper Donat
+ *
+ * @author Kacper "Kadet" Donat <kacper@kadet.net>
+ *
+ * Full license available in separate LICENSE file
+ */
+
+class TestObject
+{
+    public function identity($x)
+    {
+        return $x;
+    }
+
+    private function priv()
+    {
+        return 'foo';
+    }
+
+    public function test()
+    {
+        return ref([$this, 'priv']);
+    }
+}
+
+class RandomTest extends \PHPUnit\Framework\TestCase
+{
+    public function testApplicationOfArrayNotation()
+    {
+        $object = new TestObject();
+        $this->assertSame(10, apply([$object, 'identity'], 10));
+    }
+
+    public function testReferencingPrivateFunctionsFromInsideOfObject()
+    {
+        $object = new TestObject();
+        $reference = $object->test();
+
+        $this->assertSame('foo', $reference());
+    }
+
+    /**
+     * @expectedException \Kadet\Functional\Exception\NoAccessException
+     */
+    public function testReferencingPrivateFunctionsFromOutsideOfObject()
+    {
+        $object = new TestObject();
+
+        ref([$object, 'priv']);
+    }
+}