19.2 Overview of all accessibility tests
The following briefly introduces all accessibility checks possible with QF-Test. A detailed overview of the individual checks, as well as their configurable parameters, can be found in Configuring the "Accessibility Checks" node.
19.2.1 Axe checks with QF-Test
Errors when checking a website with axe are listed in the run log under the following error code:
QF-Test error code:
ERR_AXE-CORE_CHECKS
The axe-core library provides methods to test web pages for conformance with
accessibility standards, such as the WCAG guidelines mentioned above.
With QF-Test, you can utilize the full functionality of axe-core with no additional
programming effort.
NoteQF-Test extends axe with the capability to check elements inside closed shadow roots for accessibility. However, this is only possible when using CDP-Driver connection mode.
When using the axe library, the accessibility tests (axe rules) provided by axe are executed.
A list of all possible accessibility tests, as well as references to the guidelines they check, can
be
found here:
dequeuniversity.com/rules/axe/html/.
When running the quickstart Wizard, the rules or rule groups to execute can be defined. A more detailed description can be found in Rules to Check – axe.
The quickstart wizard offers several examples. The default value is "WCAG 2.x Level A and AA" - a check of all WCAG guidelines from version 2.0 at Level A or AA.
19.2.2 Color contrast check for simple graphics
Errors when checking graphic elements of a website are listed in the run log under the following
error code:
QF-Test error code:
ERR_COLOR_CONTRAST_SIMPLE_GRAPHICS
WCAG requires a minimum color contrast of 3:1 for images of large-scale text, user interface components, and graphics that convey information (WCAG 2.2 §§ 1.4.3, 1.4.11).
The color contrast check verifies the color contrast of simple graphic elements (such as icons) against the automatically determined background color, attempting to exclude any borders of the element.
The color contrast check examines all elements of the types specified in the quickstart wizard (or directly in the "Generic Classes" parameter of the YAML notation of Accessibility Checks), namely the Generic classes.
You can easily determine an element’s generic class by inspecting the element with the "UI Inspector". You can adapt component recognition for web tests or define your own generic classes via The Install CustomWebResolver node.
19.2.3 Focus visible check
Errors when checking graphic elements of a website are listed in the run log under the following
error code:
QF-Test error code:
ERR_FOCUS_VISIBLE
WCAG requires that elements of a keyboard-operable graphical user interface must have a
visible focus (WCAG 2.2 § 2.4.7).
The "Focus Visible" check iterates through all focusable elements of a webpage using the Tab key,
verifying the visibility of the focus each time.
19.2.4 Checking the "lang" attribute
Errors when checking a website’s lang attribute are listed in the run log under the
following
error code:
QF-Test error code:
ERR_LANGUAGE_LANG_VALUE
For users of assistive technologies, it is important to receive information on web pages in the
correct
language.
To detect the language, the lang attribute must be set correctly in the HTML
(WCAG 2.2 §§ 3.1.1, 3.1.2).
The "Checking the lang Attribute" check compares all <HTML> tags and elements with a
lang
attribute set against a user-defined language value (such as "de" or "en") for equality.
It also ensures that the attribute is set on <HTML> tags.
Here, QF-Test also checks elements from embedded HTML documents (<iframe> and inline frames).
19.2.5 The "impact" rating of accessibility tests
The developers of axe-core assigned an "impact" to each rule. This value is listed by QF-Test in the error messages for the rules and quantifies the impact of a problem on a user with a disability. An impact rating has also been assigned for the accessibility tests in QF-Test. Listed in ascending order (by severity of impact), the categories are:
- Minor: low priority
- An annoying or irritating issue.
- Moderate: medium priority
- Causes difficulties for users with impairments but generally does not prevent access to core functionality.
- Serious: high priority
- Creates significant barriers for people with disabilities and prevents them, wholly or in part, from accessing core functions or content.
- Critical: highest priority
- The issue completely blocks people with disabilities from using the site’s core functionality and accessing the content.
Note The "impact" rating enables prioritization when fixing issues. However, to comply with WCAG guidelines, all issues must be resolved - even low-priority ones.