I haven't had much luck slot of the time it just adds a comment saying "rest of tests here" which is annoying.
I have had good success with it generating things like JSDOC/doc strings and sending git diff and asking it to create a "developer friendly summary for use in a pull request description"
Did you mean ``` {"foo":{"bar":"baz"}} ```
?
By the way, have you had success at asking GPT to generate unit tests that include edge cases? I've been wondering about that.