Go Swagger Annotation Considered deadcode

[shanedetsch]

The golangci-lint deadcode lint incorrectly considers swagger annotation as dead code.

The golangci-lint version

# golangci-lint --version
golangci-lint has version 1.30.0 built from 45b90f6 on 2020-08-03T03:10:34Z

The golangcli-lint validation failure

  {
    "description": "deadcode: `appSwaggerParameterDefinition` is unused",
    "fingerprint": "A4AB72*********E99AEAA3D",
    "location": {
      "path": "app/server.go",
      "lines": {
        "begin": 110
      }
    }
  },

However this is not dead code as it is a type of swagger annotation.

// DEFINED HERE
// Swagger parameters for the post endpoint
// swagger:parameters SwaggerParameterDefinition
type appSwaggerParameterDefinition struct {
	// The POST body for creating an Item
	// in: body
	// required: true
	Body service.RequestItemForPost
	// The integration type
	// in: path
	// required: true
	// example: {genericType}
	itemType string `json: "itemType"`
}

// USED HERE
// Swagger Docs for the post sql server endpoint where SwaggerParameterDefinition is a link to the Swagger parameters for this endpoint
// swagger:route POST /{itemType}/endpoint SwaggerParameterDefinition
// Returns created Item
// Schemes: http
// Responses:
//  200: okResponse
//  500: errorResponse
// handlePostItem creates an Item
func (s *IntegrationService) handlePostItem(c echo.Context) error {

[boring-cyborg]

Hey, thank you for opening your first Issue ! 🙂 If you would like to contribute we have a guide for contributors.

[shanedetsch]

Work around

// nolint:deadcode
 type appSwaggerParameterDefinition struct {
        // The POST body for creating an Item

[SVilgelm]

It's not mentioned anywhere, you need to use it somewhere in the code. Now the deadcode linter show the correct message, the appSwaggerParameterDefinition is unused in provided sample

I would suggest you to use it in the handler:

func (s *IntegrationService) handlePostItem(c echo.Context) error {
var doc appSwaggerParameterDefinition
c.Bind(&doc)
...
}

[shanedetsch]

@SVilgelm Your solution is clever, however I think Go Swagger ties the annotation in the handler and struct definition so instantiating the struct from the context in the handler isn't necessary.

[SVilgelm]

nope, it's not doing any magic, appSwaggerParameterDefinition should be used in generated code then.

If you have a generated code and that code uses the appSwaggerParameterDefinition and the dead code ignores that usage, only then it's a bug

otherwise you have a definition, but go does not use it and it probably uses map[string]interface{} instead of the appSwaggerParameterDefinition struct

[shanedetsch]

Well the code is not used in production however the Swagger annotation is used by the ( swagger ) cli which will use a code ( model scan ) to generate apidocs. Thus maybe the best solution is to just use ( nolint:deadcode ).

[SVilgelm]

actually you just store the definitions and uses them in another project. In this case yes you are right, using the nolint:deadcode is a solution, but it's definitely not a bug of the deadcode linter

[shanedetsch]

Yeah right probably not a ( deadcode ) bug I see now.

[SVilgelm]

so. I'm closing the issue

[shanedetsch]

Yeah close, hopefully other people who are confused by swaggers interaction with deadcode can find this thread useful and use ( nolint:deadcode )