Accessibility Use Case Definition Language (UCDL) and Runner

This appendix is informative.

id: login-success
title: 'Log In To The System'
type: positive
description: 'Verify that a user with valid credentials can log in.'

preconditions:
  - 'User has a valid username and password'
  - 'User is not already logged in'

start_location: 'https://www.example.com'
expected_result: 'The user is logged in and redirected to the dashboard'

data:
  username: '[email protected]'
  password: 'xyzpdq123!)'
  dashboard_url: 'https://www.example.com/dashboard'

steps:
  - locate: link "Client Sign In"
  - focus: link "Client Sign In"
  - activate: link "Client Sign In"
  - verify: url "https://www.example.com/login.php"
  - locate: field "username"
  - focus: field "username"
  - enter: field "username" value "{{ username }}"
  - locate: field "password"
  - focus: field "password"
  - enter: field "password" value "{{ password }}"
  - locate: button "Login"
  - focus: button "Login"
  - activate: button "Login"
  - verify: url "{{ dashboard_url }}"

id: login-error-short-password
title: 'Log In — Alt 1 (Error State)'
type: negative
extends: login-success
description: 'Trigger error handling by providing a too-short password'

data:
  password: 'abc'

steps_override:
  from_step: 11
  steps:
    - 'activate: button "Login"'
    - 'verify: alert "Errors are preventing successful submission of this form."'
    - 'verify: field_error "password"'

After resolution, this case re-uses the parent's first 10 steps with password: 'abc' re-interpolated, then runs the three override steps.

- audit: page level "AA"
- activate: button "Search"
- audit: region "Search Results"

The first audit checks the whole page; the third checks only the search results region after the search completes.

id: smoke
title: 'Site renders'
type: positive
start_location: 'https://www.example.com'
expected_result: 'A landing page is shown'
steps:
  - locate: heading "Welcome"

id: every-image-has-alt
title: 'Every image on the page exposes an accessible name'
type: positive
start_location: 'https://www.example.com'
expected_result: 'Every img has alt text other than the empty string'

scope:
  for_each: 'role "img"'

steps:
  - locate: self
  - verify: self attribute "alt" present

This produces an iterations array in the report — one entry per img on the page — plus an iteration_summary with total, passed, failed, and inapplicable counts. If the page has zero images the case is reported as inapplicable, not as a failure.

id: headings-are-not-skipped
title: 'No heading skips levels relative to its predecessor'
type: positive
start_location: 'https://www.example.com'
expected_result: 'Each heading is at most one level deeper than its predecessor'

scope:
  for_each: 'criteria sequential_headings'

steps:
  - locate: self
  - verify: self attribute "data-level-jump" is "ok"

The host process supplies a resolver for the sequential_headings criteria via RunOptions.criteriaResolver; the resolver returns either a CSS selector string or an array of locators. When no resolver is configured the runner fails the case with a clear error.