CSS tests have some particular requirements for metadata.

Title element

<title>[Test Area]: [Title/Scope of Test]</title>
<title>[Test Area] Reference File</title>

The title appears in the generated index, so make sure it is concise and descriptive. The role of the title is to identify what specific detail of a feature or combination of features is being tested, so that someone looking through an index can see quickly what's tested in which file. In most cases, this description should not require more than 5 or 6 words. There is no need to provide the chapter or section in the title. For reference file, the titles should not be specific to a test case as these files may be used by multiple different tests.

Bad examples:

<title>CSS Test: Border Conflict Resolution</title>
<title>CSS Regions auto-height Reference</title>

Good examples:

<title>CSS Test: Border Conflict Resolution (width) - hidden/double
<title>CSS Reference File</title>

For CSS specifications other than CSS 2.1, you can include the module name somewhere before the colon, like “CSS Selectors Test:” or “CSS Test (Selectors):”. Do not include the module version number, since the test might get reused for the next version.


<link rel="author" title="NAME_OF_AUTHOR"
href="[mailto:some@address or http://some.url]" />

Credits provide a way to identify the person or organization that created the test and/or holds copyright in the test. This is useful for reviewing purposes and for asking questions about the individual test. A test can have multiple author credits if necessary.

Example 1:

<link rel="author" title="Boris Zbarsky"
href="mailto:bzbarsky@mit.edu" />

Example 2:

<link rel="author" title="Bert Bos"
href="http://www.w3.org/People/Bos/" />

Example 3:

<link rel="author" title="Microsoft" href="http://microsoft.com/" />


<link rel="reviewer" title="NAME_OF_REVIEWER" href="[mailto:some@address
or http://some.url]" /> <!-- YYYY-MM-DD -->

If a test has passed review, then the reviewer should note this by adding his or her name as a reviewer, along with the date of the review. A test can have multiple reviewers if necessary. A reviewer must be a person, not an organization.

Example 1:

<link rel="reviewer" title="Boris Zbarsky"
href="mailto:bzbarsky@mit.edu" /> <!-- 2008-02-19 -->

Example 2:

<link rel="reviewer" title="Bert Bos"
href="http://www.w3.org/People/Bos/" /> <!-- 2005-05-03 -->

If a test would pass review with some (non-metadata) changes and the reviewer chooses to make these changes, then the reviewer should add his or her name as a reviewer-author, along with the date of the review, when checking in those changes. This indicates that the reviewer-author approves of the original author's test when taken with these proposed changes, and that someone else (possibly the original author) must review the changes. The test is fully reviewed only when the latest reviewer did not also contribute changes to the test at the time of the review.

Example of a fully-reviewed test:

<link rel="author" title="Bert Bos"
href="http://www.w3.org/People/Bos/" />
<link rel="reviewer author" title="Boris Zbarsky"
href="mailto:bzbarsky@mit.edu" /> <!-- 2008-02-19 -->
<link rel="reviewer" title="Bert Bos"
href="http://www.w3.org/People/Bos/" /> <!-- 2008-04-22 -->

This test was written by Bert Bos, then reviewed by Boris Zbarsky, who made some corrections before deeming it acceptable. Those corrections were then reviewed and accepted by Bert Bos.

Specification Links

Specification Links

<link rel="help" href="RELEVANT_SPEC_SECTION" />

The specification link elements provide a way to align the test with information in the specification being tested.

  • Links should link to relevant sections within the specification
  • Use the anchors from the specification's Table of Contents
  • A test can have multiple specification links
    • Always list the primary section that is being tested as the first item in the list of specification links
    • Order the list from the most used/specific to least used/specific
    • There is no need to list common incidental features like the color green if it is being used to validate the test unless the case is specifically testing the color green
  • If the test is part of multiple test suites, link to the relevant sections of each spec.

Example 1:

<link rel="help"
href="http://www.w3.org/TR/CSS21/text.html#alignment-prop" />

Example 2:

<link rel="help"
href="http://www.w3.org/TR/CSS21/text.html#alignment-prop" />
<link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#q7" />
<link rel="help"
href="http://www.w3.org/TR/CSS21/visudet.html#line-height" />
<link rel="help"
href="http://www.w3.org/TR/CSS21/colors.html#background-properties" />

Reference Links

Reftests only

<link rel="match" href="RELATIVE_PATH_TO_REFERENCE_FILE" />
<link rel="mismatch" href="RELATIVE_PATH_TO_REFERENCE_FILE" />

The reference link elements are used in reftests and provide the list of reference file(s) that the test should be compared to.

  • match references must be files that render identically to the test, but use an alternate means to do so
  • Multiple match references are used when the test can match any of the reference files
    • If a test requires multiple match references that all need to match (for example, to catch when a reference fails in the same way the test does), then chain the references together, i.e.: place reference links to the additional match references in the reference files. It is recommended that the chained reference files form a loop (e.g.: a → b → c → a) so that a test linking to any reference in the chain will find all the references.
  • mismatch references are files that render differently than the test file. A test may have any number of mismatch references. The test is considered to fail if it renders the same as any of the mismatch references.
    • Note that reference files may themselves have mismatch references. In that case the reference file must not render the same as any of its mismatch references in order to be considered valid. If a reference is considered invalid (by the fact of not matching any of its match references, or matching any of its mismatch references), then a test that refers to the reference will be considered to have failed.
  • Reference files may be dedicated reference files, images, or other tests

Example 1:

<link rel="match" href="green-box-ref.xht" />

Example 2:

<link rel="match" href="green-box-ref.xht" />
<link rel="match" href="blue-box-ref.xht" />
<link rel="mismatch" href="red-box-notref.xht" />
<link rel="mismatch" href="red-box-notref.xht" />

Requirement Flags

Example 1 (one token applies):

<meta name="flags" content="invalid" />

Example 2 (multiple tokens apply):

<meta name="flags" content="ahem image scroll" />

Example 3 (no tokens apply):

<meta name="flags" content="" />

Test Assertions

<meta name="assert" content="TEST ASSERTION" />

This element should contain a complete detailed statement expressing what specifically the test is attempting to prove. If the assertion is only valid in certain cases, those conditions should be described in the statement.

The assertion should not be:

  • A copy of the title text
  • A copy of the test verification instructions
  • A duplicate of another assertion in the test suite
  • A line or reference from the CSS specification unless that line is a complete assertion when taken out of context.

The test assertion is optional. It helps the reviewer understand the goal of the test so that he or she can make sure it is being tested correctly. Also, in case a problem is found with the test later, the testing method (e.g. using color to determine pass/fail) can be changed (e.g. to using background-color) while preserving the intent of the test (e.g. testing support for ID selectors).

Examples of good test assertions:

  • “This test checks that a background image with no intrinsic size covers the entire padding box.”
  • “This test checks that ‘word-spacing’ affects each space (U+0020) and non-breaking space (U+00A0).”
  • “This test checks that if ‘top’ and ‘bottom’ offsets are specified on an absolutely-positioned replaced element, then any remaining space is split amongst the ‘auto’ vertical margins.”
  • “This test checks that ‘text-indent’ affects only the first line of a block container if that line is also the first formatted line of an element.”