diff --git a/app/Handlers/UlbXmlImportHandler.php b/app/Handlers/UlbXmlImportHandler.php
index 575f63e..7b1657b 100644
--- a/app/Handlers/UlbXmlImportHandler.php
+++ b/app/Handlers/UlbXmlImportHandler.php
@@ -75,7 +75,7 @@ class UlbXmlImportHandler
      */
     protected $availableFiles = [];
 
-    public function __construct(OutputStyle $output)
+    public function __construct(OutputStyle $output = null)
     {
         $this->output = $output;
     }
@@ -100,7 +100,7 @@ class UlbXmlImportHandler
         foreach ($this->availableFiles as $name => $filepath) {
             $this->importBook($name, $filepath);
         }
-        $this->output->writeln("<info>DONE.</info>", OutputInterface::VERBOSITY_NORMAL);
+        $this->writeln("DONE");
     }
 
     /**
@@ -112,7 +112,7 @@ class UlbXmlImportHandler
     {
         $this->currentBookNumber = $this->parseBookNumberFromFilepath($filepath);
 
-        $this->output->write("<info>Importing $bookTitle from $filepath</info> Chapters: ", false, OutputInterface::VERBOSITY_NORMAL);
+        $this->write("Importing $bookTitle from $filepath Chapters: ", false);
 
         $this->document = $this->openBook($filepath);
 
@@ -128,7 +128,7 @@ class UlbXmlImportHandler
             $book->chapters()->save($chapter);
         }
 
-        $this->output->write("<info>Done.</info>", true, OutputInterface::VERBOSITY_NORMAL);
+        $this->write("Done.", true);
 
         return $book;
     }
@@ -142,7 +142,7 @@ class UlbXmlImportHandler
         $chapterName = $this->parseChapterName($chapterElem);
         $this->currentChapterNumber = $chapterName;
 
-        $this->output->write($chapterName . ".", false, OutputInterface::VERBOSITY_NORMAL);
+        $this->write($chapterName . ".", false);
 
         $chapter = Chapter::create([
             'id' => implode('-', [$book_id, $chapterName]),
@@ -498,10 +498,24 @@ class UlbXmlImportHandler
      */
     protected function parseBookTitle(string $bookTitle) : array
     {
-        if (is_int((int) substr($bookTitle, 0, 1))) {
+        if (is_numeric(substr($bookTitle, 0, 1))) {
             return [ substr($bookTitle, 0, 1),  substr($bookTitle, 1) ];
         } else {
             return [ $bookTitle ];
         }
     }
+
+    protected function write($message, $newline)
+    {
+        if ($this->output !== null && $this->output instanceof OutputStyle) {
+            $this->output->write("<info>$message</info>", $newline, OutputInterface::VERBOSITY_NORMAL);
+        }
+    }
+
+    protected function writeln($message)
+    {
+        if ($this->output !== null && $this->output instanceof OutputStyle) {
+            $this->output->writeln("<info>$message</info>", OutputInterface::VERBOSITY_NORMAL);
+        }
+    }
 }
diff --git a/tests/Unit/UlbXmlImportHandlerTest.php b/tests/Unit/UlbXmlImportHandlerTest.php
new file mode 100644
index 0000000..2d28379
--- /dev/null
+++ b/tests/Unit/UlbXmlImportHandlerTest.php
@@ -0,0 +1,38 @@
+<?php
+namespace Tests\Unit;
+
+use App\Handlers\UlbXmlImportHandler;
+use Tests\TestCase;
+
+class UlbXmlImportHandlerTest extends TestCase
+{
+    public function testThatParseBookTitleHandlesNumberedBooksCorrectly()
+    {
+        $handler = new UlbXmlImportHandler();
+
+        $reflection_class = new \ReflectionClass(UlbXmlImportHandler::class);
+        $method = $reflection_class->getMethod('parseBookTitle');
+        $method->setAccessible(true);
+
+        $result = $method->invoke($handler, '1corinthians');
+        $this->assertEquals(['1', 'corinthians'], $result);
+
+        $result = $method->invoke($handler, 'john');
+        $this->assertEquals(['john'], $result);
+    }
+
+    public function testThatPrepareBookNameReturnsProperlyFormattedName()
+    {
+        $handler = new UlbXmlImportHandler();
+
+        $reflection_class = new \ReflectionClass(UlbXmlImportHandler::class);
+        $method = $reflection_class->getMethod('prepareBookName');
+        $method->setAccessible(true);
+
+        $result = $method->invoke($handler, '1corinthians');
+        $this->assertEquals('1 Corinthians', $result);
+
+        $result = $method->invoke($handler, 'john');
+        $this->assertEquals('John', $result);
+    }
+}