Error Summary component init function is monkeypatched in GOV.UK Design System

[lfdebrux]

Copied from Trello ticket https://trello.com/c/VIpSULRT/

Cause

Error summary component by default takes focus on page load; for examples in the Design System pages this is not desirable, so the behaviour is overridden:

govuk-design-system/src/javascripts/govuk-frontend.js

Line 30 in 61383c3

this.$module.addEventListener('click', ErrorSummary.prototype.handleClick.bind(this))

Consequences

• Risk of breaking the error summary examples in the Design System if we updated the init function or refactored the component such that the patched function no longer worked correctly.
• Risk of missing functionality in the Design System if we added new functionality and forgot to update the patched init function.

Impact of debt

Low, as it should only really affect us.

Effort to pay down

Low, though we do need to work out a way to deal with this holistically.

Overall rating

Medium

[vanitabarrett]

Once alphagov/govuk-frontend#2494 has been released, we should be able to remove this code and use the disableAutoFocus macro option in the error summary component itself instead.