goas

The project is based on

• yvasiyarov/swagger repository.
• uudashr/go-module repository.

Generate OpenAPI Specification json file with comments in Go.

Limit

• Only support go module.
• Anonymous struct field is not supported.

Install

go get -u github.com/mikunalpha/goas

Usage

Comments in main.go

// @Version 1.0.0
// @Title Backend API
// @Description API usually works as expected. But sometimes its not true.
// @ContactName Abcd
// @ContactEmail [email protected]
// @ContactURL http://someurl.oxox
// @TermsOfServiceUrl http://someurl.oxox
// @LicenseName MIT
// @LicenseURL https://en.wikipedia.org/wiki/MIT_License
// @Server http://www.fake.com Server-1
// @Server http://www.fake2.com Server-2

Comments for API handleFunc

type User struct {
  ID   uint64 `json:"id" example:"100" description:"User identity"`
  Name string `json:"name" example:"Mikun"` 
}

type UsersResponse struct {
  Data []Users `json:"users" example:"[{\"id\":100, \"name\":\"Mikun\"}]"`
}

type Error struct {
  Code string `json:"code"`
  Msg  string `json:"msg"`
}

type ErrorResponse struct {
  ErrorInfo Error `json:"error"`
}

// @Title Get user list of a group.
// @Description Get users related to a specific group.
// @Param  groupID  path  int  true  "Id of a specific group."
// @Success  200  object  UsersResponse  "UsersResponse JSON"
// @Failure  400  object  ErrorResponse  "ErrorResponse JSON"
// @Resource users
// @Route /api/group/{groupID}/users [get]
func GetGroupUsers() {
  // ...
}

// @Title Get user list of a group.
// @Description Create a new user.
// @Param  user  body  User  true  "Info of a user."
// @Success  200  object  User           "UsersResponse JSON"
// @Failure  400  object  ErrorResponse  "ErrorResponse JSON"
// @Resource users
// @Route /api/user [post]
func PostUser() {
  // ...
}

Go to the folder where is main.go in

// go.mod and main file are in the same directory
goas --module-path . --output oas.json

// go.mod and main file are in the different directory
goas --module-path . --main-file-path ./cmd/xxx/main.go --output oas.json

HandleFunc Comments

Title & Description

@Title {title}
@Title Get user list of a group.

@Description {description}.
@Description Get users related to a specific group.

• {title}: The title of the route.
• {description}: The description of the route.

Parameter

@Param  {name}  {in}  {goType}  {required}  {description}
@Param  user    body  User      true        "Info of a user."

• {name}: The parameter name.
• {in}: The parameter is in path, query, form, header, cookie, body or file.
• {goType}: The type in go code. This will be ignored when {in} is file.
• {required}: true, false, required or optional.
• {description}: The description of the parameter. Must be quoted.

Response

@Success  {stauts}  {jsonType}  {goType}       {description}
@Success  200       object      UsersResponse  "UsersResponse JSON"

@Failure  {stauts}  {jsonType}  {goType}       {description}
@Failure  400       object      ErrorResponse  "ErrorResponse JSON"

• {status}: The HTTP status code.
• {jsonType}: The value can be object or array.
• {goType}: The type in go code.
• {description}: The description of the response. Must be quoted.

Resource & Tag

@Resource {resource}
@Resource users

@Tag {tag}
@tag xxx

• {resource}, {tag}: Tag of the route.

Route

@Route {path}    {method}
@Route /api/user [post]

• {path}: The URL path.
• {method}: The HTTP Method. Must be put in brackets.