Generating Nancy API from swagger specification using BeezUp dotnet-codegen and Handlebars.Net.
This an experimental code generator tool which allow the generation of the backbone of a service based on a swagger specification.
The idea is to generate:
- The Nancy module (i.e controller) of the service, as an abstract class allowing customization of the route behavior (specifically security issues). It should handle exception mapping with HTTP status code, given the swagger response spec for that route as well as, of course, the response status code.
- The request DTO with its validator (using FluentValidation), and default validation pattern given the swagger specs, both for the request and for the nested objects, recursively. Each validator being an extendable abstract class.
- The response DTO (the first 2XX response found on the specification), which usually is a swagger definition, rendered as an extendable partial class.
- The swagger definition objects, also with their validators, with a special attention given to the inlined object definition (rendered as ValueTuple) and enum.
complexObjectE:
type: object
properties:
pack_type:
type: string
enum:
- nice
- naughty
- huge_bonus
- immortal
- stocking_killer
team:
type: string
enum: [aog, au, afs, cgs, cpp, egc, fea, hl, sbr, uosp, vt]
something:
type: object
additionalProperties:
type: object
additionalProperties:
type: object
properties:
propA:
type: integer
format: int64
propB:
type: object
properties:
propC:
type: integer
format: int64
propD:
type: object
additionalProperties:
type: object
additionalProperties:
type: string
format: date-time
public partial class ComplexObjectE
{
public Pack_type Pack_type {get; set; }
public Team Team {get; set; }
public IEnumerable<(string, IEnumerable<(string, ( long propA , ( long propC , IEnumerable<(string, IEnumerable<(string, DateTime )> )> propD ) propB ))> )> Something {get; set; }
}- The service interface, which, implemented, will send back to the controller the required response.
swagger: "2.0"
info:
description: "This is a sample server Petstore server. You can find out more about Swagger at <a href=\"http://swagger.io\">http://swagger.io</a> or on irc.freenode.net, #swagger. For this sample, you can use the api key \"special-key\" to test the authorization filters"
version: 1.0.0
title: Swagger Petstore YAML
termsOfService: "http://swagger.io/terms/"
contact:
email: "apiteam@swagger.io"
license:
name: Apache 2.0
url: "http://www.apache.org/licenses/LICENSE-2.0.html"
basePath: /v2
x-product:
appName: petStoreApp
appService: petStore
[...]
paths:
/pet:
post:
tags:
- pet
summary: Add a new pet to the store
description: ""
operationId: addPet
consumes:
- application/json
- application/xml
produces:
- application/xml
- application/json
parameters:
- in: body
name: body
description: Pet object that needs to be added to the store
required: true
schema:
$ref: "#/definitions/Pet"
responses:
"201":
schema:
$ref: "#/definitions/Pet"
description: successful operation
"400":
description: Invalid ID supplied
"405":
description: Invalid input
[...]
public interface IPetStoreService
{
Task< Pet > AddPet(AddPetRequest request);
[...]
} public abstract class PetStoreModuleBase : NancyModule
{
public PetStoreModuleBase(IPetStoreService petStoreService) : base("/v2")
{
Post("/pet", async (parameters, token) =>
{
ConfigureAddPetRequestRoute();
return await this.EvaluateAndBind<AddPetRequest>(async (request) => await petStoreService.AddPet(request), HttpStatusCode.Created );
});
}
[...]
protected virtual void ConfigureAddPetRequestRoute()
{
}
[...]
} public partial class AddPetRequest
{
public Pet Body { get; set; }
public override bool Equals(object obj)
{
return obj is AddPetRequest && obj.GetHashCode() == GetHashCode();
}
public override int GetHashCode()
{
unchecked
{
var hashCode = nameof(AddPetRequest).GetHashCode();
if (default != Body) hashCode = (hashCode * 397) ^ Body.GetHashCode();
return hashCode;
}
}
}
public class HttpResponseAddPet400Exception : Exception, IHasHttpServiceError
{
[...]
}
public class HttpResponseAddPet405Exception : Exception, IHasHttpServiceError
{
[...]
}
public class AddPetRequestValidator : AbstractValidator<AddPetRequest>
{
public AddPetRequestValidator()
{
RuleFor(request => request.Body).NotNull().WithMessage("Body is required");
}
}
}definitions:
Pet:
required:
- name
- photoUrls
properties:
id:
type: integer
format: int64
category:
$ref: "#/definitions/Category"
name:
type: string
example: doggie
photoUrls:
type: array
xml:
name: photoUrl
wrapped: true
items:
type: string
tags:
type: array
xml:
name: tag
wrapped: true
items:
$ref: "#/definitions/Tag"
petStatus:
type: string
description: pet status in the store
enum:
- available
- pending
- sold
xml:
name: Pet
public partial class Pet
{
public long Id {get; set; }
public Category Category {get; set; }
public string Name {get; set; }
public IEnumerable< string > PhotoUrls {get; set; }
public IEnumerable<Tag> Tags {get; set; }
public PetStatus PetStatus {get; set; }
}
public abstract class PetValidatorBase : AbstractValidator<Pet>
{
public PetValidatorBase()
{
RuleFor(dto => dto.Name).NotNull().NotEmpty().WithMessage("Name is required");
RuleFor(dto => dto.PhotoUrls).NotNull().WithMessage("PhotoUrls is required");
}
}