aspida

Features

• Path, URL query, header, body, and response can all specify the type
• FormData / URLSearchParams content can also specify the type
• HTTP client supports axios / fetch / node-fetch

Procedure

1. Reproduce the endpoint directory structure in the "api" directory
2. Export a Type alias named "Methods"
3. Call "aspida" with npm scripts
4. API type definition file "api/$api.ts" will be generated, so import the application and make an HTTP request

Getting Started

Installation (axios ver.)

• Using npm:

  $ npm install aspida @aspida/axios axios

• Using Yarn:

  $ yarn add aspida @aspida/axios axios

Create "api" directory

$ mkdir api

Create an endpoint type definition file

• GET: /v1/users/?limit={number}

• POST: /v1/users

  api/v1/users/index.ts

  import type { DefineMethods } from "aspida";
  
  type User = {
    id: number;
    name: string;
  };
  
  export type Methods = DefineMethods<{
    get: {
      query?: {
        limit: number;
      };
  
      resBody: User[];
    };
  
    post: {
      reqBody: {
        name: string;
      };
  
      resBody: User;
      /**
       * reqHeaders(?): ...
       * reqFormat: ...
       * status: ...
       * resHeaders(?): ...
       * polymorph: [...]
       */
    };
  }>;

• GET: /v1/users/${userId}

• PUT: /v1/users/${userId}

  api/v1/users/_userId@number/index.ts

  Specify the type of path variable “userId” starting with underscore with “@number”
  If not specified with @, the default path variable type is "number | string"

  import type { DefineMethods } from "aspida";
  
  type User = {
    id: number;
    name: string;
  };
  
  export type Methods = DefineMethods<{
    get: {
      resBody: User;
    };
  
    put: {
      reqBody: {
        name: string;
      };
  
      resBody: User;
    };
  }>;

Build type definition file

package.json

{
  "scripts": {
    "api:build": "aspida"
  }
}

$ npm run api:build

> api/$api.ts was built successfully.

Make HTTP request from application

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const userId = 0;
  const limit = 10;
  const client = api(aspida());

  await client.v1.users.post({ body: { name: "taro" } });

  const res = await client.v1.users.get({ query: { limit } });
  console.log(res);
  // req -> GET: /v1/users/?limit=10
  // res -> { status: 200, body: [{ id: 0, name: "taro" }], headers: {...} }

  const user = await client.v1.users._userId(userId).$get();
  console.log(user);
  // req -> GET: /v1/users/0
  // res -> { id: 0, name: "taro" }
})();

aspida official HTTP clients

• @aspida/axios
• @aspida/fetch
• @aspida/node-fetch

Command Line Interface Options

Options of aspida.config.js

| Option | Type | Default | Description | | -------------------- | ------------------------------------ | ------- | ----------------------------------------------------- | | input | string | "api" | Specifies the endpoint type definition root directory | | baseURL | string | "" | Specify baseURL of the request | | trailingSlash | boolean | false | Append / to the request URL | | outputEachDir | boolean | false | Generate $api.ts in each endpoint directory | | outputMode (>=1.6.0) | "all" | "normalOnly" | "aliasOnly" | "all" | Output either get or $get for compression |

Node.js API

import { version, build, watch } from "aspida/dist/commands";

console.log(version()); // 0.x.y

build();
build("./app/aspida.config.js");
build({ input: "api1" });
build([
  { baseURL: "https://example.com/v1" },
  {
    input: "api2",
    baseURL: "https://example.com/v2",
    trailingSlash: true,
    outputEachDir: true,
    outputMode: "all",
  },
]);

watch();
watch("./app/aspida.config.js");
watch({ input: "api1" });
watch([
  { baseURL: "https://example.com/v1" },
  {
    input: "api2",
    baseURL: "https://example.com/v2",
    trailingSlash: true,
    outputEachDir: true,
    outputMode: "all",
  },
]);

Ecosystem

• openapi2aspida - Convert OpenAPI 3.0 and Swagger 2.0 definitions
• aspida-mock - TypeScript friendly RESTful API mock
• frourio - Fast and type-safe full stack framework, for TypeScript TypeScript
• @aspida/react-query - React Query wrapper
• @aspida/swr - SWR (React Hooks) wrapper
• @aspida/swrv - SWRV (Vue Composition API) wrapper
• eslint-plugin-aspida - Support writing aspida api definition

Tips

1. Change the directory where type definition file is placed to other than "api"
2. Serialize GET parameters manually
3. POST with FormData
4. POST with URLSearchParams
5. Receive response with ArrayBuffer
6. Define polymorphic request
7. Define endpoints that contain special characters
8. Import only some endpoints
9. Retrieve endpoint URL string
10. Reflect TSDoc comments

Change the directory where type definition file is placed to other than "api"

Create a configuration file at the root of the project

aspida.config.js

module.exports = { input: "src" };

Specify baseURL in configuration file

module.exports = { baseURL: "https://example.com/api" };

If you want to define multiple API endpoints, specify them in an array

module.exports = [{ input: "api1" }, { input: "api2", baseURL: "https://example.com/api" }];

Serialize GET parameters manually

aspida leaves GET parameter serialization to standard HTTP client behavior
If you want to serialize manually, you can use config object of HTTP client

src/index.ts

import axios from "axios";
import qs from "qs";
import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(
    aspida(axios, { paramsSerializer: params => qs.stringify(params, { indices: false }) })
  );

  const users = await client.v1.users.$get({
    // config: { paramsSerializer: (params) => qs.stringify(params, { indices: false }) },
    query: { ids: [1, 2, 3] },
  });
  console.log(users);
  // req -> GET: /v1/users/?ids=1&ids=2&ids=3
  // res -> [{ id: 1, name: "taro1" }, { id: 2, name: "taro2" }, { id: 3, name: "taro3" }]
})();

POST with FormData

api/v1/users/index.ts

import type { DefineMethods } from "aspida";
import type { ReadStream } from "fs";

export type Methods = DefineMethods<{
  post: {
    reqFormat: FormData;

    reqBody: {
      name: string;
      icon: File | ReadStream;
    };

    resBody: {
      id: number;
      name: string;
    };
  };
}>;

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  const user = await client.v1.users.$post({
    body: {
      name: "taro",
      icon: imageFile,
    },
  });
  console.log(user);
  // req -> POST: h/v1/users
  // res -> { id: 0, name: "taro" }
})();

Post in Node.js (>=1.6.0)

src/index.ts

import fs from "fs";
import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());
  const fileName = "images/sample.jpg";
  const user = await client.v1.users.$post({
    body: {
      name: "taro",
      icon: fs.createReadStream(fileName),
    },
  });
  console.log(user);
  // req -> POST: h/v1/users
  // res -> { id: 0, name: "taro" }
})();

POST with URLSearchParams

api/v1/users/index.ts

import type { DefineMethods } from "aspida";

export type Methods = DefineMethods<{
  post: {
    reqFormat: URLSearchParams;

    reqBody: {
      name: string;
    };

    resBody: {
      id: number;
      name: string;
    };
  };
}>;

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  const user = await client.v1.users.$post({ body: { name: "taro" } });
  console.log(user);
  // req -> POST: /v1/users
  // res -> { id: 0, name: "taro" }
})();

Receive response with ArrayBuffer

api/v1/users/index.ts

import type { DefineMethods } from "aspida";

export type Methods = DefineMethods<{
  get: {
    query: {
      name: string;
    };

    resBody: ArrayBuffer;
  };
}>;

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  const user = await client.v1.users.$get({ query: { name: "taro" } });
  console.log(user);
  // req -> GET: /v1/users/?name=taro
  // res -> ArrayBuffer
})();

Define polymorphic request

api/users/index.ts

type User = {
  id: number;
  name: string;
};

export interface Methods {
  post: {
    // common properties
    reqFormat: FormData;
    /**
     * query(?): ...
     * reqHeaders(?): ...
     * reqBody(?): ...
     * status: ...
     * resHeaders(?): ...
     * resBody(?): ...
     */
    polymorph: [
      // polymorphic types
      {
        reqBody: Omit<User, "id">;
        resBody: User;
        /**
         * query(?): ...
         * reqHeaders(?): ...
         * status: ...
         * resHeaders(?): ...
         */
      },
      {
        reqBody: Omit<User, "id">[];
        resBody: User[];
      }
    ];
  };
}

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  const user = await client.users.$post({ body: { name: "taro" } });
  console.log(user); // { id: 0, name: "taro" }

  const users = await client.users.$post({
    body: [{ name: "hanako" }, { name: "mario" }],
  });
  console.log(users); // [{ id: 1, name: "hanako" }, { id: 2, name: "mario" }]
})();

Define endpoints that contain special characters

Special characters are encoded as percent-encoding in the file name
Example ":" -> "%3A"

api/foo%3Abar/index.ts

import type { DefineMethods } from "aspida";

export type Methods = DefineMethods<{
  get: {
    resBody: string;
  };
}>;

api/users/_userId@number%3Aread/index.ts

import type { DefineMethods } from "aspida";

export type Methods = DefineMethods<{
  get: {
    resBody: User;
  };
}>;

With clients, "%3A" -> ":"

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  const message = await client.foo_bar.$get();
  console.log(message);
  // req -> GET: /foo:bar

  const user = await client.users._userId_read(1).$get();
  console.log(user);
  // req -> GET: /users/1:read
})();

Import only some endpoints

If you don't need to use all of api/$api.ts , you can split them up and import only part of them
outputEachDir option generates $api.ts in each endpoint directory
$api.ts will not be generated under the directory containing the path variable

aspida.config.js

module.exports = { outputEachDir: true };

Import only $api.ts of the endpoint you want to use and put it into Object

src/index.ts

import aspida from "@aspida/axios";
import api0 from "../api/v1/foo/$api";
import api1 from "../api/v2/bar/$api";
(async () => {
  const aspidaClient = aspida();
  const client = {
    foo: api0(aspidaClient),
    bar: api1(aspidaClient),
  };

  const message = await client.bar._id(1).$get();
  // req -> GET: /v2/bar/1
})();

Retrieve endpoint URL string

src/index.ts

import aspida from "@aspida/axios";
import api from "../api/$api";
(async () => {
  const client = api(aspida());

  console.log(client.v1.users.$path());
  // /v1/users

  console.log(client.vi.users.$path({ query: { limit: 10 } }));
  // /v1/users?limit=10

  console.log(
    client.vi.users.$path({
      method: "post",
      query: { id: 1 },
    })
  );
  // /v1/users?id=1
})();

Reflect TSDoc comments

api/index.ts

import type { DefineMethods } from "aspida";

/**
 * root comment
 *
 * @remarks
 * root remarks comment
 */
export type Methods = DefineMethods<{
  /**
   * post method comment
   *
   * @remarks
   * post method remarks comment
   */
  post: {
    /** post query comment */
    query: { limit: number };

    /** post reqHeaders comment */
    reqHeaders: { token: string };

    reqFormat: FormData;
    /** post reqBody comment */
    reqBody: UserCreation;

    /**
     * post resBody comment1
     * post resBody comment2
     */
    resBody: User;
  };
}>;

$ npm run api:build

api/$api.ts

/**
 * root comment
 *
 * @remarks
 * root remarks comment
 */
const api = <T>({ baseURL, fetch }: AspidaClient<T>) => {
  return {
    /**
     * post method comment
     *
     * @remarks
     * post method remarks comment
     *
     * @param option.query - post query comment
     * @param option.headers - post reqHeaders comment
     * @param option.body - post reqBody comment
     * @returns post resBody comment1
     * post resBody comment2
     */
    $post: (option: {
      body: Methods0["post"]["reqBody"];
      query: Methods0["post"]["query"];
      headers: Methods0["post"]["reqHeaders"];
      config?: T;
    }) =>
      fetch<Methods0["post"]["resBody"]>(prefix, PATH0, POST, option)
        .json()
        .then(r => r.body),
  };
};

License

aspida is licensed under a MIT License.