Add a unit test for StringType.

Cover the uncovered cases around string types.

tests/TestCase/Database/Type/StringTypeTest.php

@@ -0,0 +1,101 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         3.1.7
+ * @license       http://www.opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\Test\TestCase\Database\Type;
+
+use Cake\Database\Type;
+use Cake\Database\Type\IntegerType;
+use Cake\TestSuite\TestCase;
+use \PDO;
+
+/**
+ * Test for the String type.
+ */
+class StringTypeTest extends TestCase
+{
+
+    /**
+     * Setup
+     *
+     * @return void
+     */
+    public function setUp()
+    {
+        parent::setUp();
+        $this->type = Type::build('string');
+        $this->driver = $this->getMock('Cake\Database\Driver');
+    }
+
+    /**
+     * Test toPHP
+     *
+     * @return void
+     */
+    public function testToPHP()
+    {
+        $this->assertNull($this->type->toPHP(null, $this->driver));
+        $this->assertSame('word', $this->type->toPHP('word', $this->driver));
+        $this->assertSame('2.123', $this->type->toPHP(2.123, $this->driver));
+    }
+
+    /**
+     * Test converting to database format
+     *
+     * @return void
+     */
+    public function testToDatabase()
+    {
+        $obj = $this->getMock('StdClass', ['__toString']);
+        $obj->method('__toString')->will($this->returnValue('toString called'));
+
+        $this->assertNull($this->type->toDatabase(null, $this->driver));
+        $this->assertSame('word', $this->type->toDatabase('word', $this->driver));
+        $this->assertSame('2.123', $this->type->toDatabase(2.123, $this->driver));
+        $this->assertSame('toString called', $this->type->toDatabase($obj, $this->driver));
+    }
+
+    /**
+     * Tests that passing an invalid value will throw an exception
+     *
+     * @expectedException InvalidArgumentException
+     * @return void
+     */
+    public function testToDatabseInvalidArray()
+    {
+        $this->type->toDatabase([1, 2, 3], $this->driver);
+    }
+
+    /**
+     * Test marshalling
+     *
+     * @return void
+     */
+    public function testMarshal()
+    {
+        $this->assertNull($this->type->marshal(null));
+        $this->assertSame('word', $this->type->marshal('word'));
+        $this->assertSame('2.123', $this->type->marshal(2.123));
+        $this->assertSame('', $this->type->marshal([1, 2, 3]));
+    }
+
+    /**
+     * Test that the PDO binding type is correct.
+     *
+     * @return void
+     */
+    public function testToStatement()
+    {
+        $this->assertEquals(PDO::PARAM_STR, $this->type->toStatement('', $this->driver));
+    }
+}