From 231c9242a4d0fd131d9ee7def68b01e349cee2b3 Mon Sep 17 00:00:00 2001
From: widmogrod <widmogrod@gmail.com>
Date: Wed, 20 Dec 2017 18:42:55 +0100
Subject: [PATCH] Functiona\reverse tests

---
 src/Functional/functions.php    |  6 ++--
 test/Functional/ReverseTest.php | 73 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 2 deletions(-)
 create mode 100644 test/Functional/ReverseTest.php

diff --git a/src/Functional/functions.php b/src/Functional/functions.php
index f8aa857..2d3b403 100644
--- a/src/Functional/functions.php
+++ b/src/Functional/functions.php
@@ -138,6 +138,8 @@ function tee(callable $function = null, $value = null)
 const reverse = 'Widmogrod\Functional\reverse';
 
 /**
+ * reverse :: (a -> b -> c -> d) -> (c -> b -> a -> d)
+ *
  * Call $function with arguments in reversed order
  *
  * @return \Closure
@@ -146,8 +148,8 @@ const reverse = 'Widmogrod\Functional\reverse';
  */
 function reverse(callable $function)
 {
-    return function () use ($function) {
-        return call_user_func_array($function, array_reverse(func_get_args()));
+    return function (...$args) use ($function) {
+        return $function(...array_reverse($args));
     };
 }
 
diff --git a/test/Functional/ReverseTest.php b/test/Functional/ReverseTest.php
new file mode 100644
index 0000000..3a0bd28
--- /dev/null
+++ b/test/Functional/ReverseTest.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace test\Functional;
+
+use function Widmogrod\Functional\reverse;
+
+class ReverseTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider provideData
+     */
+    public function test_it_should_create_function_that_accept_args_in_reverse_order(
+        callable $function,
+        array $args
+    ) {
+        $reversed = reverse($function);
+        $original = reverse($reversed);
+
+        $this->assertSame(
+            $original(...$args),
+            $function(...$args),
+            'Reverse of revert function should be the same function'
+        );
+        $this->assertSame(
+            $reversed(...array_reverse($args)),
+            $function(...$args),
+            'Reversing arguments to reverse function should result in the same value as the function'
+        );
+    }
+
+    public function provideData()
+    {
+        return [
+            'non argument function' => [
+                '$function' => function () {
+                    return 1;
+                },
+                '$value' => [],
+            ],
+            'non argument function but with args' => [
+                '$function' => function () {
+                    return 1;
+                },
+                '$value' => [1, 2, 3],
+            ],
+            'many args' => [
+                '$function' => function ($a, $b, $c, $d) {
+                    return ($a - $c) * pow($b, $d);
+                },
+                '$value' => [
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                ],
+            ],
+            'variadic args' => [
+                '$function' => function (...$args) {
+                    return array_product($args);
+                },
+                '$value' => [
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                    random_int(-10, 10),
+                ],
+            ],
+        ];
+    }
+}
-- 
2.11.0