CSS Metadata

CSS tests have some additional metadata.

Specification Links

Each test requires at least one link to specifications:

<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="https://www.w3.org/TR/CSS21/text.html#alignment-prop" />

Example 2:

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

Requirement Flags

If a test has any of the following requirements, a meta element can be added to include the corresponding flags (tokens):

Token	Description
asis	The test has particular markup formatting requirements and cannot be re-serialized.
HTMLonly	Test case is only valid for HTML
invalid	Tests handling of invalid CSS. Note: This case contains CSS properties and syntax that may not validate.
may	Behavior tested is preferred but OPTIONAL. [RFC2119]
nonHTML	Test case is only valid for formats besides HTML (e.g. XHTML or arbitrary XML)
paged	Only valid for paged media
scroll	Only valid for continuous (scrolling) media
should	Behavior tested is RECOMMENDED, but not REQUIRED. [RFC2119]

The following flags are deprecated and should not be declared by new tests. Tests which satisfy the described criteria should simply be designated as “manual” using the -manual file name flag.

Token	Description
animated	Test is animated in final state. (Cannot be verified using reftests/screenshots.)
font	Requires a specific font to be installed at the OS level. (A link to the font to be installed must be provided; this is not needed if only web fonts are used.)
history	User agent session history is required. Testing :visited is a good example where this may be used.
interact	Requires human interaction (such as for testing scrolling behavior)
speech	Device supports audio output. Text-to-speech (TTS) engine installed
userstyle	Requires a user style sheet to be set

Example 1 (one token applies):

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

Example 2 (multiple tokens apply):

<meta name="flags" content="asis HTMLonly may" />

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, but is highly recommended. 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.”