SilverStripe Testing - Director::test not working as expect

-- mysite/tests/HomePageTest.yaml:

HomePage:
    home:
        Title: Home Page 12
        Content: This is the content of home
        URLSegment: home

-- mysite/tests/HomePageTest.php
<?php
class HomePageTest extends SapphireTest {
    static $fixture_file = 'HomePageTest.yml';

    private $someVar = "nothing";
    public function setUp() {
        parent::setUp();
        $this->someVar = "this is set in setUp";

    }
    /**
     * sample unit test with 3 assertions
     */
    public function testUnitHome() {
        $fixture = "home";
        $obj = $this->objFromFixture("HomePage", $fixture);
        $this->assertEquals("Home Page 12", $obj->getTitle());
        $this->assertEquals("this is set in setUp", $this->someVar);
        $this->assertTrue(stripos($obj->getField('Content'), 'This is the content of home') !== false);
    }

    /**
     * sample functional test
     */
    public function testFunctionalHome() {
        $response = Director::test('');
        $body = $response->getBody();
        $this->assertTrue(stripos($body, '<head>') !== false);
    }

    /**
     * functional test: see if js are there
     */
    public function testJsThere() {
        $response = Director::test('home/');
        $body = $response->getBody();
        echo "\n\n". $body ."\n\n";
        $jss = array(
            '<script src="themes/bootstrap/js/bootstrap-modal.js"></script>',
        );
        foreach ($jss as $js) {
            $this->assertTrue(stripos($body, $js) !== false);
        }
    }
}
?>

OUTPUT:
...
Page not found
...

3 tests run: 3 passes, 0 failures, and 0 incomplete with 0 errors

EXPECTED:
This is the content of home
instead of
Page not found