public function testGenerateOnlyHeaderReportFile()
{
$exporter = new HtmlExporter();
$report = new Report('<section class="content">Content</section>', '<section class="header">Header</section>');
$file = $exporter->generate($report);
$this->assertFileExists($file);
$expectHtml = '<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>' . $exporter->getFileName() . '</title></head><body style="background-color: #ffffff;"><section class=\'header\'>Header</section><section class="content">Content</section></body></html>';
$this->assertStringEqualsFile($file, $expectHtml);
}
