<html> <strong> <div style=“color: red; font-size: 20px; border: 2px solid red; padding: 10px; line-height: 1.5; text-align: center;”> This page has been deprecated and is no longer being maintained. <br>For up to date information on contributing and authoring CSS Test suites, see: <br><a href=“http://testthewebforward.org/docs/test-style-guidelines.html#self-describing-tests”>http://testthewebforward.org/docs/test-style-guidelines.html#self-describing-tests</a> </strong> </div> </html>

Self-Describing Tests

A self-describing test is a test page that describes what the page should look like when the test has passed. A human examining the test page can then determine from the description whether the test has passed or failed.

The following are some examples of self-describing tests, using common techniques to identify passes:

Self-describing tests have some advantages:

They can be run easily on any layout engine.
They can test areas of the spec that are not precise enough to be comparable to a reference rendering. (For example, underlining cannot be compared to a reference because the position and thickness of the underline is UA-dependent.)
Failures can (should) be easily determined by a human viewing the test without needing special tools.

They also have some disadvantages:

They cannot be automated: a human must determine whether the test has passed or failed.
In some cases it is difficult or impossible to design the test for a glaringly obvious pass or fail. (In these cases, if it's possible to create a reference, the reftest format may be more appropriate.)

Self-describing tests must follow the CSS test format guidelines.

Additional information on writing self-describing tests is available on the W3C site.