nock-swagger

nock-swagger

This projects autogenerates strongly typed methods to easily set up nock mocks for API calls based on Swagger API definitions. So, given that you have a petstore-like API definition, you could autogenerate a list of nock helper methods, to easily mock methods from the API.

This library requires, dotnet runtime (2.1) installed on your machine! If you have .NET Core 3+ or 5+ you'll need to add a switch (e.g. /runtime:Net50) to all commands.

How to use

Check out tests for few examples. Shortly, mocking GET requests will look like this:

Nock.getPetById({ id: 1 } /* GET parameters with type & intellisense */)
  .reply({ id:1, name: 'mypet' });

It's not that different from the Nock itself, just that:

• you don't have to remember/write the URL (it will be filled in automatically)
• you don't have to remember query parameters & their types (intellisense will help you)
• you will have intellisense for Reply as well (so you know the shape of the object to return)

Don't forget to set the base url by calling setBaseUrl('https://localhost'). Also go read the nock docs if you have any problem regarding how Nock works.

More details:

• You get an autogenerated list of functions (function per API endpoint). E.g. Nock.getPetById, Nock.findPetByStatus, Nock.addPet. The 'Nock' part actually depends on your Swagger definition (it's a Controller name, unless it's not empty).
• Each function has the same typings as nock.post/get/put, except that the first parameter is not uri: string, but a typed interface with path/query parameters. E.g.

  getPetById: (
    queryParams: GetPetByIdNockParameters, /* Strongly typed, not just `url: string`  */
    requestBody?: RequestBodyMatcher,
    interceptorOptions?: Options & { preservePreviousInterceptors?: boolean },
  )
  type GetPetByIdNockParameters = {
    petId: number;
  };
  

• Each function returns exactly the same Interceptor as nock.post(...), but typings are different. E.g. reply function has the following typing:

    reply(
      responseCode?: StatusCode,
      body?: IPet, /* strongly typed, not just `Body` */
      headers?: ReplyHeaders,
    ): Scope;

All other reply overloads are correctly typed as well. Another example (for POST /store/order):

    reply(
      replyFnWithCallback: (
        this: ReplyFnContext,
        uri: string,
        body: Order, /* body is correctly typed */
        callback: (
          err: NodeJS.ErrnoException | null,
          result: ReplyFnResultGeneric<IOrder>, /* result function is typed as well */
        ) => void,
      ) => void,
    ): Scope;

Notice, however, that uri is still not typed in all reply overloads. If you want the actual values of your query parameters, please use new URLSearchParams(url), or some other parsing library. nock-swagger might someday implement it as well, but it will require rewriting the reply function, while currently only typings are different (the Interceptor itself is exactly what is returned from nock).

Perks

Auto-removing old interceptors

Nock by default doesn't remove the 'old' interceptors when you define a new one for the same route/query params. It wasn't convenient for me, so nock-swagger removes old interceptors by default. If you want to preserve previously configured interceptors for the same root (God knows why are you adding a new Interceptor if you don't want it to work, but still), you need to pass preservePreviousInterceptors: true as part of interceptorOptions (usually 3rd argument of every nock setup call).

How to add

Install the package into your project using yarn/npm (as a dev-dependency). You'll also need to add react-query (which you probably already have if you are interested in this library).

yarn add -D nock-swagger

Then create/update your autogenerated hooks by calling (adjusting the URL and output path)

yarn nock-swagger /input:https://petstore.swagger.io/v2/swagger.json /output:__tests__/nock-helpers.ts

You would probably want to add this script to your package.json to call it every time your API changes.

Configuration

setBaseUrl(baseUrl: string)

Sets base URL for all methods

How does it work

Under the cover it's just 2 template files for NSwag and a small script to easily use them.

Contributions and support

Issues and Pull Requests are welcome.

For any kind of private consulting or support you could contact Artur Drobinskiy directly via email.