Programmatic API

It is possible to use the Massimo client without the generator.

OpenAPI Client

Basic Usage

ESM (ECMAScript Module)

import { buildOpenAPIClient } from "massimo";

const client = await buildOpenAPIClient({
  url: `https://yourapi.com/documentation/json`,
  // path: 'path/to/openapi.json',
  headers: {
    foo: "bar",
  },
});

const res = await client.yourOperationName({ foo: "bar" });

console.log(res);

CommonJS

const { buildOpenAPIClient } = require("massimo");

(async () => {
  const client = await buildOpenAPIClient({
    url: `https://yourapi.com/documentation/json`,
    // path: 'path/to/openapi.json',
    headers: {
      foo: "bar",
    },
  });

  const res = await client.yourOperationName({ foo: "bar" });

  console.log(res);
})();

Accessing Operation Mapping

Once you have a client generated from buildOpenAPIClient, you can access a mapping between operation IDs and method/path by leveraging the Symbol.for('plt.operationIdMap') property

const client = await buildOpenAPIClient({
  // ... your client settings
});

const mapping = client[Symbol.for("plt.operationIdMap")];

console.log(mapping);

Example Output

{
  "getOperationFoo": { "path": "/operation-foo/", "method": "get" },
  "postOperationBar": { "path": "/operation-bar/", "method": "post" }
}

Dynamic Headers

You can pass an asynchronous function to modify the headers for each request with the getHeaders option. This function will be executed before each request. Note that headers and getHeaders can work together:

ESM Example

import { buildOpenAPIClient } from "massimo";

const client = await buildOpenAPIClient({
  url: `https://yourapi.com/documentation/json`,
  headers: {
    foo: "bar",
  },
  getHeaders(options) {
    const { url, method, body, headers, telemetryHeaders } = options;

    // generate your dynamic headers

    return {
      myDynamicHeader: "my-value",
    };
  },
});

const res = await client.yourOperationName({ foo: "bar" });

console.log(res);

CommonJS Example

const { buildOpenAPIClient } = require("massimo");

(async () => {
  const client = await buildOpenAPIClient({
    url: `https://yourapi.com/documentation/json`,
    headers: {
      foo: "bar",
    },
    getHeaders(options) {
      const { url, method, body, headers, telemetryHeaders } = options;

      // generate your dynamic headers

      return {
        myDynamicHeader: "my-value",
      };
    },
  });

  const res = await client.yourOperationName({ foo: "bar" });

  console.log(res);
})();

Optional properties

You can also pass the following properties to buildOpenAPIClient:

import { Agent } from "undici";
import { buildOpenAPIClient } from "massimo";

const client = await buildOpenAPIClient({
  url: "string", // the URL of the service to be called
  path: "string", // the path to the Open API schema
  fullResponse: true, // require or not a full response object
  fullRequest: true, // require or not a full request object
  throwOnError: true, // if there is an error, the client will throw depending ton this option
  headers: {}, // additional headers to be passed
  bodyTimeout: 900000, // body timeout passed to the undici request method
  headersTimeout: 900000, // headers timeout passed to the undici request method
  validateResponse: true, // validate or not the response received against the expected schema
  queryParser: (query) => `${query.toString()}[]`, // override the default query parser logic
  dispatcher: new Agent(), // optional property that allows passing a custom undici Agent
});

TypeScript Support

If you use Typescript, you can take advantage of the generated types file:

import { buildOpenAPIClient } from "massimo";
import Client from "./client";
//
// interface Client {
//   getMovies(req: GetMoviesRequest): Promise<Array<GetMoviesResponse>>;
//   createMovie(req: CreateMovieRequest): Promise<CreateMovieResponse>;
//   ...
// }
//

const client: Client = await buildOpenAPIClient<Client>({
  url: `https://yourapi.com/documentation/json`,
  // path: 'path/to/openapi.json',
  headers: {
    foo: "bar",
  },
});

const res = await client.getMovies();
console.log(res);

GraphQL Client

To create a GraphQL client, use the buildGraphQLClient function:

ESM Example

import { buildGraphQLClient } from "massimo";

const client = await buildGraphQLClient({
  url: `https://yourapi.com/graphql`,
  headers: {
    foo: "bar",
  },
});

const res = await client.graphql({
  query: `
    mutation createMovie($title: String!) {
      saveMovie(input: {title: $title}) {
        id
        title
      }
    }
  `,
  variables: {
    title: "The Matrix",
  },
});

console.log(res);

CommonJS Example

const { buildGraphQLClient } = require("massimo");

(async () => {
  const client = await buildGraphQLClient({
    url: `https://yourapi.com/graphql`,
    headers: {
      foo: "bar",
    },
  });

  const res = await client.graphql({
    query: `
      mutation createMovie($title: String!) {
        saveMovie(input: {title: $title}) {
          id
          title
        }
      }
    `,
    variables: {
      title: "The Matrix",
    },
  });

  console.log(res);
})();