Add ::proxy() operation.

spec/drupol/collection/CollectionSpec.php

@@ -607,6 +607,28 @@ public function it_can_prepend(): void
             ->shouldReturn(['A', 'B', 'C', 'D', 'E', 'F']);
     }
 
+    public function it_can_proxy(): void
+    {
+        $input1 = new \ArrayObject(\range('A', 'E'));
+        $input2 = new \ArrayObject(\range(1, 5));
+
+        $this
+            ->beConstructedThrough('with', [[$input1, $input2]]);
+
+        $this
+            ->proxy('map', 'count')
+            ->all()
+            ->shouldReturn([5, 5]);
+
+        $this
+            ->shouldThrow(\Exception::class)
+            ->during('proxy', ['map', 'foo']);
+
+        $this
+            ->shouldThrow(\Exception::class)
+            ->during('proxy', ['foo', 'foo']);
+    }
+
     public function it_can_rebase(): void
     {
         $this

src/Collection.php

@@ -25,6 +25,7 @@
 use drupol\collection\Operation\Pad;
 use drupol\collection\Operation\Pluck;
 use drupol\collection\Operation\Prepend;
+use drupol\collection\Operation\Proxy;
 use drupol\collection\Operation\Range;
 use drupol\collection\Operation\Rebase;
 use drupol\collection\Operation\Skip;
@@ -304,6 +305,14 @@ public function prepend(...$items): CollectionInterface
         return $this->run(Prepend::with(...$items));
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function proxy(string $method, string $proxyMethod, ...$parameters): CollectionInterface
+    {
+        return $this->run(Proxy::with($method, $proxyMethod, $parameters));
+    }
+
     /**
      * Create a new with a range of number.
      *

src/Contract/Collection.php

@@ -4,6 +4,8 @@
 
 namespace drupol\collection\Contract;
 
+use drupol\collection\Contract\Collection as CollectionInterface;
+
 /**
  * Interface Collection.
  */
@@ -220,6 +222,15 @@ public function pluck($pluck, $default = null): self;
      */
     public function prepend(...$items): self;
 
+    /**
+     * @param string $method
+     * @param string $proxyMethod
+     * @param mixed ...$parameters
+     *
+     * @return \drupol\collection\Contract\Collection
+     */
+    public function proxy(string $method, string $proxyMethod, ...$parameters): CollectionInterface;
+
     /**
      * @return \drupol\collection\Contract\Collection
      */

src/Operation/Proxy.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace drupol\collection\Operation;
+
+use drupol\collection\Collection;
+use drupol\collection\Contract\Collection as CollectionInterface;
+
+/**
+ * Class Proxy.
+ */
+final class Proxy extends Operation
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function run(CollectionInterface $collection): CollectionInterface
+    {
+        [$method, $proxyMethod, $parameters] = $this->parameters;
+
+        $callback = static function ($value) use ($proxyMethod, $parameters) {
+            $reflection = new \ReflectionClass($value);
+
+            if (false === $reflection->hasMethod($proxyMethod)) {
+                throw new \InvalidArgumentException(\sprintf('Proxy method %s does not exist.', $proxyMethod));
+            }
+
+            return $reflection
+                ->getMethod($proxyMethod)
+                ->invoke($value, ...$parameters);
+        };
+
+        $reflection = new \ReflectionClass($collection);
+
+        if (false === $reflection->hasMethod($method)) {
+            throw new \InvalidArgumentException(\sprintf('Method %s does not exist.', $method));
+        }
+
+        return Collection::with($reflection
+            ->getMethod($method)
+            ->invoke($collection->rebase(), $callback));
+    }
+}