Description

Following on from the ListView multi-select behaviour added in #38314, this PR adds test coverage for the TreeGrid component's callback functions, to ensure that the expected contract is maintained when we make changes to the component. This includes:

• Test coverage for onExpandRow callback, that returns the DOM element for the row to be expanded
• Test coverage for onCollapseRow callback, that returns the DOM element for the row to be collapsed
• Test coverage for the onFocusRow callback, that returns the event that was fired, the starting row DOM element, and the destination row DOM element

Testing Instructions

From the command line run the following:

npm run test-unit -- --testPathPattern packages/components/src/tree-grid/test/index.js

Screenshots

Types of changes

Code quality / test coverage.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).
• I've updated related schemas if appropriate.