NEW Add a couple of basic test classes

tests/DocumentConverterDecoratorTest.php

@@ -0,0 +1,19 @@
+<?php
+
+class DocumentConverterDecoratorTest extends SapphireTest
+{
+    protected $requiredExtensions = array(
+        'SiteTree' => array(
+            'DocumentConverterDecorator',
+        ),
+    );
+
+    public function testFieldListHasDocumentImportField()
+    {
+        $fields = (new SiteTree)->getCMSFields();
+        $this->assertInstanceOf(
+            'DocumentImportField',
+            $fields->fieldByName('Root.Import')->Fields()->First()
+        );
+    }
+}

tests/DocumentImportFieldTest.php

@@ -0,0 +1,51 @@
+<?php
+
+class DocumentImportFieldTest extends SapphireTest
+{
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testConstructorThrowsExceptionWhenGivenString()
+    {
+        new DocumentImportField('exception time!');
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testConstructorThrowsExceptionWhenGivenChildren()
+    {
+        new DocumentImportField(['i', 'don\'t', 'like', 'kids']);
+    }
+
+    public function testFieldAddsJavascriptRequirements()
+    {
+        // Start with a clean slate (no global state interference)
+        Requirements::backend()->clear();
+
+        new DocumentImportField();
+        $javascript = Requirements::backend()->get_javascript();
+        $this->assertNotEmpty($javascript);
+    }
+
+    public function testFieldListGeneration()
+    {
+        $importField = new DocumentImportField();
+
+        $fields = $importField->getChildren();
+        $this->assertInstanceOf('FieldList', $fields);
+
+        // We don't need to check that all of the fields are there, but just check a couple
+        $this->assertInstanceOf('HeaderField', $fields->fieldByName('FileWarningHeader'));
+        $innerField = $fields->fieldByName('ImportedFromFile');
+        $this->assertInstanceOf('DocumentImportInnerField', $innerField);
+
+        // Check the getter works
+        $this->assertSame($innerField, $importField->getInnerField());
+
+        // Check the fields have been given has the change tracker disabled
+        $splitHeader = $fields->fieldByName('DocumentImportField-SplitHeader');
+        $this->assertInstanceOf('DropdownField', $splitHeader);
+        $this->assertContains('no-change-track', $splitHeader->extraClass());
+    }
+}