Errors returned in REST now include the attribute name
API
Effective June 05, 2018
We've changed the error messages returned in REST responses to include the attribute name, which matches what we currently return in GraphQL.
For example:
Before:
errors['title'] = ["can't be blank"]
After:
errors['title'] = ["Title can't be blank"]
If you have any apps that display the errors messages to merchants or customers, then you should make sure that the new text is rendered correctly and the attribute name doesn't appear twice.
Although we don't recommend parsing the error message itself for any code logic in your apps (use http status codes instead), if your app currently implements this behavior, then you need to make sure that it handles the new text appropriately.