- ✅ Whitespace and empty string handling

---

### 3. ArchiveExtractorErrorHandlingTest.java
**Purpose**: Test improved error handling in archive extractors.

**Key Test Areas**:
- Enhanced error messages
- Partial extraction (continues on failure)
- Invalid archive handling
- Empty archive handling
- Mixed valid/invalid entries

**Covered Extractors**:
- ZipExtractor
- TarExtractor

    @Resource
    protected ActivityHelper activityHelper;

    /** Manager for handling HTTP response operations. */
    @Resource
    protected ResponseManager responseManager;

    /** Time manager for handling date and time operations. */
    @Resource
    protected TimeManager timeManager;

    /** System helper for various system-level operations. */
    @Resource

- `CurlRequestTest`: Tests for request builder, headers, parameters, body content, SSL, proxies, timeouts
- `CurlResponseTest`: Tests for response handling, status codes, content retrieval, resource management
- `CurlExceptionTest`: Tests for exception handling and error scenarios

import org.lastaflute.web.response.StreamResponse;

import jakarta.annotation.Resource;

/**
 * Action class for handling document redirection requests.
 * This action processes "go" requests that redirect users to specific documents
 * while tracking click events and handling various URL types including file system paths.
 */
public class GoAction extends FessSearchAction {

    /**

 *   <li>Starting and cleaning up crawling</li>
 *   <li>Handling unsupported URLs</li>
 *   <li>Checking last modified dates</li>
 *   <li>Getting content</li>
 *   <li>Handling redirects</li>
 *   <li>Processing responses</li>
 *   <li>Handling exceptions during crawling and child URL processing</li>
 *   <li>Handling cases where no URL is in the queue</li>
 *   <li>Handling cases where no response processor or rule is found</li>

import org.codelibs.fess.util.ComponentUtil;

/**
 * Interface for transforming and processing crawled documents in Fess.
 * Provides utility methods for URL processing, site extraction, data mapping,
 * and field configuration handling during the document transformation process.
 */
public interface FessTransformer {

    /**
     * Synchronized LRU cache for storing parent URL encodings.

        assertEquals(0, controller.noUrlInQueueCount);
        assertEquals(0, controller.waitNewUrlCount);
        // Should not throw exception, just logged
    }

    /**
     * Test exception handling with ignoreException = true (default)
     */
    public void test_exceptionHandling_ignoreTrue() {
        final TestIntervalController controller = new TestIntervalController();

import org.codelibs.fess.crawler.interval.IntervalController;

/**
 * An abstract base class for implementing {@link IntervalController}.
 * Provides a common structure for handling delays at different stages of the crawling process.
 * It encapsulates the delay logic and exception handling, allowing subclasses to focus on
 * defining the specific delay behavior for each stage.
 *
 * <p>

            assertNotNull(childUrls);
            assertEquals(0, childUrls.size());
        }
    }

    public void test_processSitemapWithNullEntry() {
        // Setup - test handling of null sitemap in list
        ResponseData responseData = new ResponseData();
        byte[] content = "<sitemapindex></sitemapindex>".getBytes();
        responseData.setResponseBody(content);

     *   <li>Error handling and failure logging</li>
     *   <li>Cleanup of old documents after successful crawling</li>
     * </ul>
     */
    protected static class DataCrawlingThread extends Thread {

        /** Configuration for the data store being crawled */
        private final DataConfig dataConfig;

        /** Callback for handling document indexing operations */