Fix convert case transformer

Author: leomarquine

src/Transformers/ConvertCase.php

@@ -2,6 +2,7 @@
 
 namespace Marquine\Etl\Transformers;
 
+use Marquine\Etl\Row;
 use InvalidArgumentException;
 
 class ConvertCase extends Transformer
@@ -11,7 +12,7 @@ class ConvertCase extends Transformer
      *
      * @var array
      */
-    protected $columns;
+    protected $columns = [];
 
     /**
      * The mode of the conversion.
@@ -27,6 +28,13 @@ class ConvertCase extends Transformer
      */
     protected $encoding = 'utf-8';
 
+    /**
+     * The int representation of the mode.
+     *
+     * @var int
+     */
+    protected $conversionMode;
+
     /**
      * Properties that can be set via the options method.
      *
@@ -37,33 +45,34 @@ class ConvertCase extends Transformer
     ];
 
     /**
-     * Get the transformer handler.
+     * Initialize the step.
      *
-     * @return callable
+     * @return void
      */
-    public function transform()
+    public function initialize()
     {
-        $mode = $this->getConversionMode();
-
-        return function ($row) use ($mode) {
-            if ($this->columns) {
-                foreach ($this->columns as $column) {
-                    $row[$column] = mb_convert_case($row[$column], $mode, $this->encoding);
-                }
-            } else {
-                foreach ($row as $column => $value) {
-                    $row[$column] = mb_convert_case($value, $mode, $this->encoding);
-                }
-            }
+        $this->conversionMode = $this->getConversionMode();
+    }
 
-            return $row;
-        };
+    /**
+     * Transform the given row.
+     *
+     * @param  \Marquine\Etl\Row  $row
+     * @return void
+     */
+    public function transform(Row $row)
+    {
+        $row->transform($this->columns, function ($column) {
+            return mb_convert_case($column, $this->conversionMode, $this->encoding);
+        });
     }
 
     /**
      * Get the conversion mode.
      *
-     * @return string
+     * @return int
+     *
+     * @throws \InvalidArgumentException
      */
     protected function getConversionMode()
     {
@@ -80,6 +89,6 @@ protected function getConversionMode()
                 return MB_CASE_TITLE;
         }
 
-        throw new InvalidArgumentException('The provided conversion mode is not supported.');
+        throw new InvalidArgumentException("The conversion mode [{$this->mode}] is invalid.");
     }
 }

tests/Transformers/ConvertCaseTest.php

@@ -3,72 +3,94 @@
 namespace Tests\Transformers;
 
 use Tests\TestCase;
+use Marquine\Etl\Row;
 use Marquine\Etl\Transformers\ConvertCase;
 
 class ConvertCaseTest extends TestCase
 {
-    protected $data = [
-        ['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com'],
-        ['id' => '2', 'name' => 'JOHN DOE', 'email' => 'JOHNDOE@EMAIL.COM'],
-    ];
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->data = [
+            new Row(['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com']),
+            new Row(['id' => '2', 'name' => 'JOHN DOE', 'email' => 'JOHNDOE@EMAIL.COM']),
+        ];
+    }
 
     /** @test */
     public function lowercase()
     {
         $expected = [
-            ['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com'],
-            ['id' => '2', 'name' => 'john doe', 'email' => 'johndoe@email.com'],
+            new Row(['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com']),
+            new Row(['id' => '2', 'name' => 'john doe', 'email' => 'johndoe@email.com']),
         ];
 
         $transformer = new ConvertCase;
 
         $transformer->options(['mode' => 'lower']);
 
-        $this->assertEquals($expected, array_map($transformer->transform(), $this->data));
+        $transformer->initialize();
+
+        array_map([$transformer, 'transform'], $this->data);
+
+        $this->assertEquals($expected, $this->data);
     }
 
     /** @test */
     public function uppercase()
     {
         $expected = [
-            ['id' => '1', 'name' => 'JANE DOE', 'email' => 'JANEDOE@EMAIL.COM'],
-            ['id' => '2', 'name' => 'JOHN DOE', 'email' => 'JOHNDOE@EMAIL.COM'],
+            new Row(['id' => '1', 'name' => 'JANE DOE', 'email' => 'JANEDOE@EMAIL.COM']),
+            new Row(['id' => '2', 'name' => 'JOHN DOE', 'email' => 'JOHNDOE@EMAIL.COM']),
         ];
 
         $transformer = new ConvertCase;
 
         $transformer->options(['mode' => 'upper']);
 
-        $this->assertEquals($expected, array_map($transformer->transform(), $this->data));
+        $transformer->initialize();
+
+        array_map([$transformer, 'transform'], $this->data);
+
+        $this->assertEquals($expected, $this->data);
     }
 
     /** @test */
     public function titlecase()
     {
         $expected = [
-            ['id' => '1', 'name' => 'Jane Doe', 'email' => 'Janedoe@email.com'],
-            ['id' => '2', 'name' => 'John Doe', 'email' => 'Johndoe@email.com'],
+            new Row(['id' => '1', 'name' => 'Jane Doe', 'email' => 'Janedoe@email.com']),
+            new Row(['id' => '2', 'name' => 'John Doe', 'email' => 'Johndoe@email.com']),
         ];
 
         $transformer = new ConvertCase;
 
         $transformer->options(['mode' => 'title']);
 
-        $this->assertEquals($expected, array_map($transformer->transform(), $this->data));
+        $transformer->initialize();
+
+        array_map([$transformer, 'transform'], $this->data);
+
+        $this->assertEquals($expected, $this->data);
     }
 
     /** @test */
     public function custom_columns()
     {
         $expected = [
-            ['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com'],
-            ['id' => '2', 'name' => 'john doe', 'email' => 'JOHNDOE@EMAIL.COM'],
+            new Row(['id' => '1', 'name' => 'jane doe', 'email' => 'janedoe@email.com']),
+            new Row(['id' => '2', 'name' => 'john doe', 'email' => 'JOHNDOE@EMAIL.COM']),
         ];
 
         $transformer = new ConvertCase;
 
         $transformer->options(['columns' => ['name']]);
 
-        $this->assertEquals($expected, array_map($transformer->transform(), $this->data));
+        $transformer->initialize();
+
+        array_map([$transformer, 'transform'], $this->data);
+
+        $this->assertEquals($expected, $this->data);
     }
 }