Test markup | Apache Wicket

You need this when a test has to check the markup a page or component renders, not only which components it contains: a CSS class, an attribute, the text inside a tag. TagTester finds tags in a piece of markup and gives you their name, attributes and content. Test pages and components covers rendering the page first.

Find a tag

The tester has shortcuts that search the last response:

tester.startPage(OrderPage.class);

TagTester total = tester.getTagByWicketId("total");
TagTester status = tester.getTagById("order-status");
List<TagTester> rows = tester.getTagsByWicketId("row");

getTagByWicketId looks for the wicket:id attribute in the output. Wicket keeps that attribute in development mode, which is the default in tests, and strips it in deployment mode.

TagTester itself searches any markup string:

Method	Returns
`TagTester.createTagByName(markup, "table")`	The first `<table>` tag
`TagTester.createTagByAttribute(markup, "class", "total")`	The first tag whose `class` is exactly `total`
`TagTester.createTagsByAttribute(markup, "class", "total", false)`	Every such tag; `true` stops after the first
`TagTester.createTags(markup, tag -> ..., false)`	Every tag the function accepts

The methods return null or an empty list when nothing matches.

Check a tag

OrderPageTest.java

@Test
void showsTotalAsWarningWhenOverLimit() {
    tester.startPage(new OrderPage(Model.of(largeOrder)));

    TagTester total = tester.getTagByWicketId("total");
    assertNotNull(total);
    assertEquals("span", total.getName());
    assertTrue(total.getAttributeContains("class", "warning"));
    assertEquals("€ 12.500,00", total.getValue());
}

Method	Returns
`getName()`	The tag name
`hasAttribute(name)`	Whether the attribute is present
`getAttribute(name)`	The attribute value, or `null`
`getAttributeIs(name, value)`	Whether the value equals `value`
`getAttributeContains(name, part)`	Whether the value contains `part`
`getAttributeEndsWith(name, end)`	Whether the value ends with `end`
`getValue()`	Everything between the open and close tag
`getMarkup()`	The tag itself with everything inside it
`hasChildTag(name)`	Whether a tag with that name is nested inside
`getChild(name)`, `getChild(attribute, value)`	The first nested tag that matches, as a `TagTester`

Since Wicket 11, text fields write required, placeholder (from setLabel) and pattern (from a PatternValidator) on their <input> tag. Assertions on the attributes of an input see them on Wicket 11 only.

Check the whole response

For a quick check without finding a tag, assertContains and assertContainsNot match a regular expression against the last response:

tester.assertContains("<h1>Order 42</h1>");
tester.assertContainsNot("class=\"error\"");

tester.getLastResponseAsString() returns the markup if you want to search it yourself.

Render a component to a string

ComponentRenderer renders a page or a component outside a request and returns the markup. Use it for components whose output you test or use elsewhere, such as the body of an email:

var renderer = new ComponentRenderer();
CharSequence html = renderer.renderComponent(() -> new InvoicePanel("invoice", Model.of(invoice)));

TagTester amount = TagTester.createTagByAttribute(html.toString(), "class", "amount");
assertEquals("€ 99,00", amount.getValue());

A ComponentRenderer created without arguments uses its own mock application; new ComponentRenderer(application) uses yours. Call destroy() on it when you are done. Inside a running request, or in a test that already has a WicketTester, the static ComponentRenderer.renderComponent(component) renders a new component with the current application.

Compare a page with an expected file

executeTest renders a page and compares the output with a file next to the test class:

tester.executeTest(OrderPageTest.class, OrderPage.class, "OrderPage_expected.html");

Run the tests once with -Dwicket.replace.expected.results=true to create or update the files, and review the changes before you commit them. executeTest also takes a page instance or a component, and executeListener and executeBehavior compare the response of a listener or an Ajax behavior. These comparisons are strict: any change in the markup, including attributes a new Wicket version adds, makes them fail.