From 18241104e44ed98506a5a9f0af7c20f050abc387 Mon Sep 17 00:00:00 2001
From: widmogrod <widmogrod@gmail.com>
Date: Tue, 12 Dec 2017 22:12:03 +0100
Subject: [PATCH] Make Maybe Monoid tests more sain

---
 example/MaybeMonoidTest.php | 81 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 69 insertions(+), 12 deletions(-)

diff --git a/example/MaybeMonoidTest.php b/example/MaybeMonoidTest.php
index 7ac72b2..6ff26f3 100644
--- a/example/MaybeMonoidTest.php
+++ b/example/MaybeMonoidTest.php
@@ -2,8 +2,12 @@
 
 use Widmogrod\Functional as f;
 use Widmogrod\Monad\Maybe\Just;
-use Widmogrod\Monad\Maybe\Nothing;
+use Widmogrod\Monad\Maybe\Maybe;
 use Widmogrod\Primitive\Listt;
+use Widmogrod\Primitive\Stringg;
+use const Widmogrod\Monad\Maybe\maybeNull;
+use function Widmogrod\Functional\map;
+use function Widmogrod\Monad\Maybe\just;
 use function Widmogrod\Monad\Maybe\maybeNull;
 
 class MaybeMonoidTest extends \PHPUnit_Framework_TestCase
@@ -11,34 +15,87 @@ class MaybeMonoidTest extends \PHPUnit_Framework_TestCase
     /**
      * @dataProvider provideData
      */
-    public function test_it_should_concat_only_just_values($data, $expected)
+    public function test_it_should_concat_only_strings_and_skip_nulls(array $data, array $expected, string $asString)
     {
-        $makeMaybeMonoid = function ($val) {
+        $fullName = Listt::of($data)
+            ->map(maybeNull)
+            ->map(map(Stringg::of))
+            ->reduce(f\concatM, just(Stringg::mempty()));
+
+        $this->assertInstanceOf(Just::class, $fullName);
+        $this->assertEquals($fullName, just(Stringg::of($asString)));
+    }
+
+    /**
+     * @dataProvider provideData
+     */
+    public function test_it_should_concat_only_just_values_naive_string_implementation(array $data, array $expected, string $asString)
+    {
+        // $makeMaybeMonoid :: string -> Maybe Stringg
+        $makeMaybeMonoid = function ($val): Maybe {
+            return maybeNull($val)->map(Stringg::of);
+        };
+
+        // $names :: array Maybe Stringg
+        $names = array_values(array_map($makeMaybeMonoid, $data));
+
+        // $firstName :: Maybe Stringg
+        // $middleName :: Maybe Stringg
+        // $lastName :: Maybe Stringg
+        list($firstName, $middleName, $lastName) = $names;
+
+        // $fullName :: Maybe Stringg
+        $fullName = $firstName->concat($middleName)->concat($lastName);
+
+        $this->assertInstanceOf(Just::class, $fullName);
+        $this->assertEquals($fullName, just(Stringg::of($asString)));
+    }
+
+    /**
+     * @dataProvider provideData
+     */
+    public function test_it_should_concat_only_just_values_list_naive_implementation2(array $data, array $expected)
+    {
+        // $makeMaybeMonoid :: string -> Maybe Listt string
+        $makeMaybeMonoid = function ($val): Maybe {
             return maybeNull($val)->map(Listt::of);
         };
 
+        // $names :: array Maybe Listt string
         $names = array_values(array_map($makeMaybeMonoid, $data));
 
+        // $firstName :: Maybe Listt string
+        // $middleName :: Maybe Listt string
+        // $lastName :: Maybe Listt string
         list($firstName, $middleName, $lastName) = $names;
 
+        // $fullName :: Maybe Listt string
         $fullName = $firstName->concat($middleName)->concat($lastName);
-        $fullNameFromReduce = array_reduce($names, f\concatM, Nothing::mempty());
 
         $this->assertInstanceOf(Just::class, $fullName);
-        $this->assertEquals($fullName->extract()->extract(), $expected);
-        $this->assertEquals($fullNameFromReduce->extract()->extract(), $expected);
+        $this->assertEquals($fullName, just(Listt::of($expected)));
     }
 
     public function provideData()
     {
         return [
-            [
-                '$data'     => ['firstName' => 'First', 'middleName' => null, 'lastName' => 'Last'],
-                '$expected' => ['First', 'Last']
+            'array with null values' => [
+                '$data' => [
+                    'firstName'  => 'First',
+                    'middleName' => null,
+                    'lastName'   => 'Last'
+                ],
+                '$expected' => ['First', 'Last'],
+                '$asString' => 'FirstLast',
             ],
-            [
-                '$data'     => ['firstName' => 'First', 'middleName' => 'Middle', 'lastName' => 'Last'],
-                '$expected' => ['First', 'Middle', 'Last']
+            'array with strings' => [
+                '$data' => [
+                    'firstName'  => 'First',
+                    'middleName' => 'Middle',
+                    'lastName'   => 'Last'
+                ],
+                '$expected' => ['First', 'Middle', 'Last'],
+                '$asString' => 'FirstMiddleLast',
             ]
         ];
     }
-- 
2.11.0