Code Generation

Code Generation

RTK Query's API and architecture is oriented around declaring API endpoints up front. This lends itself well to automatically generating API slice definitions from external API schema definitions, such as OpenAPI and GraphQL.

We have early previews of code generation capabilities available as separate tools.

OpenAPI

We have a first version of a code generator from OpenAPI schemas over at rtk-incubator/rtk-query-codegen.

You can create an api by running:

curl -o petstore.json https://petstore3.swagger.io/api/v3/openapi.json
npx @rtk-incubator/rtk-query-codegen-openapi --hooks petstore.json > petstore-api.generated.ts

We recommend placing these generated types in one file that you do not modify (so you can constantly re-generate it when your API definition changes) and creating a second file to enhance it with additional info:

// file: petstore-api.generated.ts noEmit
export * from 'petstore-api.generated'

// file: petstoreApi.ts
import { api as generatedApi } from './petstore-api.generated'

export const api = generatedApi.enhanceEndpoints({
  addTagTypes: ['Pet'],
  endpoints: {
    // basic notation: just specify properties to be overridden
    getPetById: {
      providesTags: (result, error, arg) => [{ type: 'Pet', id: arg.petId }],
    },
    findPetsByStatus: {
      providesTags: (result) =>
        // is result available?
        result
          ? // successful query
            [
              { type: 'Pet', id: 'LIST' },
              ...result.map((pet) => ({ type: 'Pet' as const, id: pet.id })),
            ]
          : // an error occurred, but we still want to refetch this query when `{ type: 'Pet', id: 'LIST' }` is invalidated
            [{ type: 'Pet', id: 'LIST' }],
    },
    // alternate notation: callback that gets passed in `endpoint` - you can freely modify the object here
    addPet: (endpoint) => {
      endpoint.invalidatesTags = (result) =>
        result ? [{ type: 'Pet', id: result.id }] : []
    },
    updatePet: {
      invalidatesTags: (result, error, arg) => [
        { type: 'Pet', id: arg.pet.id },
      ],
    },
    deletePet: {
      invalidatesTags: (result, error, arg) => [{ type: 'Pet', id: arg.petId }],
    },
  },
})

export const {
  useGetPetByIdQuery,
  useFindPetsByStatusQuery,
  useAddPetMutation,
  useUpdatePetMutation,
  useDeletePetMutation,
} = api

GraphQL

There is a very early WIP PR that implements code generation based on a GraphQL spec, and an open issue on the GraphQL Generator repo asking if an RTK Query generator would be potentially useful.