Initial SQLite development (#1)

Reviewed-on: #1

tests/unit/Mapper/StringMapperTest.php

@@ -0,0 +1,29 @@
+<?php declare(strict_types=1);
+
+namespace Test\Unit\Mapper;
+
+use BitBadger\PDODocument\Mapper\StringMapper;
+use PHPUnit\Framework\TestCase;
+
+class StringMapperTest extends TestCase
+{
+    public function testMapSucceedsWhenFieldIsPresentAndString()
+    {
+        $result = ['test_field' => 'test_value'];
+        $mapper = new StringMapper('test_field');
+        $this->assertEquals('test_value', $mapper->map($result), 'String value not returned correctly');
+    }
+
+    public function testMapSucceedsWhenFieldIsPresentAndNotString()
+    {
+        $result = ['a_number' => 6.7];
+        $mapper = new StringMapper('a_number');
+        $this->assertEquals('6.7', $mapper->map($result), 'Number value not returned correctly');
+    }
+
+    public function testMapSucceedsWhenFieldIsNotPresent()
+    {
+        $mapper = new StringMapper('something_else');
+        $this->assertNull($mapper->map([]), 'Missing value not returned correctly');
+    }
+}