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How to achieve cleaner code and compile-time type-safety for your tests, probably saving 60% of your time

If you use Test Driven Development in Wicket, the first approach is often to use component's path names (e.g., page:panel:form:component) to test them. This is good bearable at first, but as your pages get more and more complicated and have deeper hierarhices, you will find yourself spending a whole lot of time debugging typos and misconceptions (in my opinnion: you would waste 60% of your time doing this). The solution is: make your component hierarcy type-safe so that you can GET all of your components when testing:

Code Block

public class TestHomePage extends TestCase {
	private WicketTester tester;

	@Override
	public void setUp() {
		tester = new WicketTester(new WicketApplication());
	}

	/**
	 * 
	 */
	public void testBookList() {
		// start and render the test page
		tester.startPage(HomePage.class);
		// assert rendered page class
		tester.assertRenderedPage(HomePage.class);
		// assert rendered label component
		tester.assertLabel("message",
				"If you see this message wicket is properly configured and running");

		// assert rendered page class
		HomePage homePage = (HomePage) tester.getLastRenderedPage();
		BookForm bookForm = homePage.getForm();
		BookListView bookListView = bookForm.getBookListView();
		List<BookListItem> bookItems = toLinkedList(bookListView.iterator());
		{
			// Test values of 1st book
			BookListItem bookListItem = bookItems.get(0); // Note: no hassle with
																										// run-time component path
																										// id's
			assertEquals("first", bookListItem.getNameField().getValue());
			assertEquals("", bookListItem.getAuthorField().getValue());
			assertEquals("-1", bookListItem.getTypeChoice().getValue());
		}
		{
			// Test values of 2nd book
			BookListItem bookListItem = bookItems.get(1); // Note: no hassle with
																										// run-time component path
																										// id's
			assertEquals("second", bookListItem.getNameField().getValue());
			assertEquals("", bookListItem.getAuthorField().getValue());
			assertEquals("-1", bookListItem.getTypeChoice().getValue());
		}
		{
			// Test values of 3rd book
			BookListItem bookListItem = bookItems.get(2); // Note: no hassle with
																										// run-time component path
																										// id's
			assertEquals("third", bookListItem.getNameField().getValue());
			assertEquals("", bookListItem.getAuthorField().getValue());
			assertEquals("-1", bookListItem.getTypeChoice().getValue());
		}

		{
			// Set new values
			FormTester formTester = tester.newFormTester(bookForm
					.getPageRelativePath());

			// formTester.setValue(bookItems.get(1).getAuthorField(), "Hemingway"); //
			// TODO New feature request
			tester.getServletRequest().setParameter(
					bookItems.get(1).getAuthorField().getInputName(), "Hemingway");

			// Submit changes
			// formTester.submit(bookForm.getSubmitButton()); // TODO New feature
			// request
			formTester.submit();
		}

		tester.assertRenderedPage(HomePage.class);
		// Verify the submitted value
		{
			// Test values of 2nd book
			BookListItem bookListItem = bookItems.get(1); // Note: no hassle with
																										// run-time component path
																										// id's
			assertEquals("second", bookListItem.getNameField().getValue());
			assertEquals("Hemingway", bookListItem.getAuthorField().getValue());
			assertEquals("-1", bookListItem.getTypeChoice().getValue());
		}
	}

	/**
	 * @param <T>
	 * @param iterator
	 * @return List<T>
	 */
	public static <T> List<T> toLinkedList(Iterator<T> iterator) {
		List<T> linkedList = new LinkedList<T>();
		for (; iterator.hasNext();) {
			linkedList.add(iterator.next());
		}

		return linkedList;
	}
}

...

Code Block

<html xmlns="http://www.w3.org/1999/xhtml" 
  xmlns:wicket="http://wicket.sourceforge.net">
    <head>
        <title>Wicket Quickstart Archetype Homepage</title>
    </head>
    <body>
        <strong>Wicket Quickstart Archetype Homepage</strong>
        <br/><br/>
        <span wicket:id="message">message will be here</span>
        
        <form wicket:id="form">
          <table border="1">
            <tr wicket:id="book_list">
              <th>Name:</th><td><input type="text" wicket:id="name"/></td>
              <th>Author:</th><td><input type="text" wicket:id="author"/></td>
              <th>Type:</th><td><select wicket:id="type"></select></td>
            </tr>
          </table>
          <input type="submit" wicket:id="submit" value="Submit"/>
        </form>
        
    </body>
</html>

The benefits of the introduced approach are:

Compile-time type-safety
By not hardcoding the runtime component paths into the tests, you can make your tests truly modular!
You save 60% of your time (the time you would have wasted banging your head to the wall of wrong paths and components)
The code is cleaner and nicer, easier to maintain
The test-code is easier to read and makes much more sense as a spec

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