ruby-grape / grape / 35456788678

100%

push

github

Send a content type for an api_format the API does not declare (#2959)

`api_format` picks the format a response is rendered in, and the media type
it is labelled with comes from the formats the API declares. A format the
API does not declare has none there, so on a `format :json` API

    get('/plain') { api_format :txt; 'plain' }

rendered `plain` under `content-type: nil`. Rack forbids a nil header value
and Rack::Lint raises on it; a server writes an empty header, or none. The
same goes for `:xml` and `:binary`. The only spec for `api_format :txt`
declares `content_type :txt, 'text/plain'` on its API, so the suite's
`Grape.config.lint` never met the nil.

An error raised after it went wrong the other way: the error middleware
falls back to text/html, and HTML-escapes a body it labels so, so
`error!('a < b', 400)` answered `a &lt; b` as text/html while rendering it
with the txt error formatter.

PrecomputedContentTypes, which both middlewares share, now answers
#media_type_for: the media type the API declares for a format, or else the
one Grape registers for it by default -- text/plain, application/xml,
application/octet-stream. The formatter labels a response with it and
leaves the header out for a format with no media type anywhere, a custom
formatter's; the error middleware labels an error with it before falling
back to text/html. #content_type_for is left as it is: negotiation, format
extensions and the 415 check ask it whether the API supports a format at
all, and a fallback there would accept formats the API never declared.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

1444 of 1501 branches covered (96.2%)

Branch coverage included in aggregate %.

6 of 6 new or added lines in 2 files covered. (100.0%)

4296 of 4296 relevant lines covered (100.0%)

28649.35 hits per line