Add Map transformer instead of Rename transformer

Author: camillebaronnet

src/Tests/Transformer/MapTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Camillebaronnet\ETL\Tests\Transformer;
+
+use Camillebaronnet\ETL\Transformer\Map;
+use PHPUnit\Framework\TestCase;
+
+final class MapTest extends TestCase
+{
+    /**
+     * @var Map
+     */
+    private $map;
+
+    /**
+     * @var array
+     */
+    private $data = [
+        'name' => 'Bar',
+        'address_street' => '1 road',
+        'address_zip' => 'xxx',
+    ];
+
+
+    protected function setUp()
+    {
+        $this->map = new Map();
+    }
+
+    public function testCanRenameSomeKeysAndRemoveUnrenamed()
+    {
+        $this->map->fields = [
+            'name' => 'TheName'
+        ];
+        $result = $this->map->__invoke($this->data);
+
+        $this->assertEquals($result, [
+            'TheName' => 'Bar'
+        ]);
+    }
+
+    public function testCanRenameSomeKeysAndKeepUnrenamed()
+    {
+        $this->map->fields = [
+            'name' => 'TheName'
+        ];
+        $this->map->keepUnmapped = true;
+        $result = $this->map->__invoke($this->data);
+
+        $this->assertEquals($result, [
+            'TheName' => 'Bar',
+            'address_street' => '1 road',
+            'address_zip' => 'xxx',
+        ]);
+    }
+
+    public function testCanMapSomeKeysWithoutRenamesItAndRemoveOther()
+    {
+        $this->map->fields = ['name', 'address_street'];
+        $result = $this->map->__invoke($this->data);
+
+        $this->assertEquals($result, [
+            'name' => 'Bar',
+            'address_street' => '1 road',
+        ]);
+    }
+}

src/Transformer/Map.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Camillebaronnet\ETL\Transformer;
+
+class Map implements TransformInterface
+{
+    public $fields = [];
+
+    public $keepUnmapped = false;
+
+    public function __invoke(array $data): array
+    {
+        foreach ($data as $key => $value) {
+            $newName = $this->fields[$key] ?? null;
+
+            if(!$newName && in_array($key, $this->fields, true)){
+                $newName = $key;
+            }
+
+            if ($newName) {
+                if ($newName !== $key) {
+                    $data[$newName] = $value;
+                    unset($data[$key]);
+                }
+            } elseif (!$this->keepUnmapped) {
+                unset($data[$key]);
+            }
+        }
+
+        return $data;
+    }
+}