fix: added http error codes

[NeelMalwatkar]

Issue : #144

• Added MethodNotAllowed (405)
• Added Conflict (409)
• Added Gone (410)
• Added UnsupportedMediaType (415)
• Added UnprocessableEntity (422)
• Added TooManyRequests (429)
• Added InternalServerError (500)
• Added NotImplemented (501)
• Added BadGateway (502)
• Added GatewayTimeout (504)
• Added RequestTimeout (408)

[ayashjorden]

Hi @NeelMalwatkar ,
This is a prime candidate for Composition (part of how the Go programing language is designed)

// 1. Define the base structure
type BaseError struct {
    Message string
}

func (e *BaseError) Error() string {
    return e.Message
}

// 2. Compose specific errors using the base
type MethodNotAllowed struct{ BaseError }
type Conflict struct{ BaseError }
type Gone struct{ BaseError }
type UnsupportedMediaType struct{ BaseError }
// ... and so on

[NeelMalwatkar]

Makes sense, i will re-write all the errors using this technique.

[ayashjorden]

While I don't want to scope-creep this PR, error_handler.go may benefit from some generalization or refactoring to make it DRY.
If this becomes tangled, I'm ok with improving in a separate PR

[NeelMalwatkar]

While I don't want to scope-creep this PR, error_handler.go may benefit from some generalization or refactoring to make it DRY. If this becomes tangled, I'm ok with improving in a separate PR

I was thinking of doing it this way:

1. errors/errors.go- Add a StatusCoder interface and a StatusCode() method to each error type:

type StatusCoder interface {
    StatusCode() int
}

// Each type gets its own status code
func (e *BadRequest) StatusCode() int    { return 400 }
func (e *NotFound) StatusCode() int      { return 404 }
func (e *Forbidden) StatusCode() int     { return 403 }
// ... same for all 16 types

2. In error_handler.go - Replace all if blocks with a single interface check:

  var sc Errors.StatusCoder
  if errors.As(err, &sc) {
      renderError(w, r, sc.StatusCode(), err.Error())
      return
  }

I can make a separate PR for this if needed.