Content-Type mismatch:
    type: text/html
    input: '{"version": "https://jsonfeed.org/version/1"}'
    exception: notJSONType

Not valid JSON 1:
    input: '{'
    exception: notJSON

Not valid JSON 2:
    input: '<rss><channel/></rss>'
    exception: notJSON

Not a JSON feed 1:
    input: '{}'
    exception: notJSONFeed

Not a JSON feed 2:
    input: '{"version": "https://example.com/"}'
    exception: notJSONFeed

Not a JSON feed 3:
    input: '{"version": "https://jsonfeed.org/version/"}'
    exception: notJSONFeed