Timebox to 5 SP.
integration test for page rest endpoint has been introduced since https://jira.magnolia-cms.com/browse/MGNLREST-700 and cover basic cases.
Due to some changes recently for this endpoint. We can add more test case to ensure below use cases:
nested areas: https://jira.magnolia-cms.com/browse/PAGES-1314
prototype aware: https://jira.magnolia-cms.com/browse/PAGES-1308
especially for https://jira.magnolia-cms.com/browse/PAGES-1325 running with anonymous case