The final goal is of this issue is to achieve ~80-100% coverage

here's a todo list of things that require tests (based on the __tests__ folder):

⚠️ List is in progress, I'll be adding new test tasks over time, here are some that you can submit already

• core
  • app
    • app - app.set, app.enable, app.disable (codecov)
    • onError - Test a case where an error doesn't have an HTTP status code, neither is a string (codecov)
  • request
  • response
• modules
  • accepts
  • cookie-signature
  • cookie
  • etag (Write tests for etag #133)
  • req (Write tests for @tinyhttp/req #140)
  • res
    • res.format - if default only is specified, call it as a function (codecov)
    • res.format - if nothing is specified, throw 406 (codecov)
  • router
  • send (Write tests for @tinyhttp/send #143)
• wares
  • cookie-parser
  • cors
    • Accept a function to set origin
  • dotenv
  • favicon
  • jwt
    • Should work with different algorithms (codecov) [pending]
  • logger
  • ping
  • bot-detector (Write tests for bot-detector #111)
  • ip-filter
  • jsonp (Write tests for @tinyhttp/jsonp #123)\

If you want to help with tests, write down to this thread with your questions