While writing some tests for my library, I stumbled upon another minor inconsistency: trying to retrieve a non-existent post will always return a response in text/plain, whether authenticated or not.

Reproduction:

❯ curl -i http://localhost:8080/api/posts/0 -H "content-type: application/json"
HTTP/1.1 404 Not Found
Cache-Control: public, max-age=604800, immutable
Content-Type: text/plain; charset=utf-8
X-Content-Type-Options: nosniff
Date: Thu, 09 Nov 2023 18:19:02 GMT
Content-Length: 19

404 page not found

Same thing happens when I try to post an update, or delete a non-existing post: the response is in text/plain. Looks like the entire /api/posts/{id} endpoint returns text/plain when the id doesn't exist, rather than the usual json.