I also got hit by the gitlab API change where the IssueEventPayload doesn't contain a field 'assignee' but only 'assignees' - even though there's only one...
Coverage: 88.208%. Remained the same when pulling c56bb26bdd587465786dd4862d10a511c7adccae on kubaraczkowski:gitlab_issue_event_assignees into 4f72f9c366d8b19787398015a3389b826c36239f on go-playground:master.
I also got hit by the gitlab API change where the IssueEventPayload doesn't contain a field 'assignee' but only 'assignees' - even though there's only one...
https://github.com/go-playground/webhooks/issues/159
The 'assignee' field is deprecated but not removed (https://docs.gitlab.com/ee/user/project/integrations/webhook_events.html#issue-events) so it's kept in the struct.