This page discusses how to use NekoHTML, HtmlUnit, Watij and WebTest to test web applications.
There are many ways to test Web Applications with Groovy:
- use Groovy (potentially in conjunction with a specialist HTML parser) to parse HTML pages as if they were XML
- use Groovy to simplify the code required to drive a Java API browser simulator, e.g. HtmlUnit or HttpUnit
- use Groovy to simplify the code required to drive a Java API for manually driving a real browser, e.g. IE or Firefox
- use Groovy to interact with a higher-level testing library which uses one of the above two approaches, e.g. Watij (for the equivalent of Watir in the Ruby world) or WebTest (to open up the possibility of testing more than just web applications)
We examine a few approaches below.
Groovy with CyberNeko HTML Parser
NekoHTML is a library which allows you to parse HTML documents (which may not be well-formed) and treat them as XML documents (i.e. XHTML). NekoHTML automatically inserts missing closing tags and does various other things to clean up the HTML if required - just as browsers do - and then makes the result available for use by normal XML parsing techniques.
Here is an example of using NekoHTML with XmlParser to find '.html' hyperlinks on the groovy homepage:
We turned off namespace processing which lets us select nodes using '.A' with no namespace.
Here is one way to do the same example with XmlSlurper:
We didn't turn off namespace processing but do the selection using just the local name, i.e. '.name()'.
Here is the output in both cases:
Now that we have the links we could do various kinds of assertions, e.g. check the number of links, check that a particular link was always on the page, or check that there are no broken links.
Groovy and HtmlUnit
The following example tests the Google search engine using HtmlUnit:
Note that to use HtmlUnit with Groovy you should not include the xml-apis-*.jar included with HtmlUnit in your CLASSPATH.
Groovy and Watij
The following example tests the Google search engine using Watij:
You can use Watij from within groovysh or groovyconsole if you want to have an interactive (irb-like in ruby terms) experience.
Groovy and WebTest
The following example tests the Google search engine using WebTest:
The above fragment can be inserted into any Ant build script where we have defined the WebTest tasks.
The above example didn't use any Groovy but we could have just as easily used some Groovy for the last line if we didn't like the XPath expression, for example:
Depending on your setup, you could produce the following report for this test:
Alternatively, we could have written the whole test in Groovy using AntBuilder as follows:
Grails can automatically create this style of test for your generated CRUD applications, see Grails Functional Testing for more details.