OpenFetch

Fetch-like OpenAPI client library. Supports OpenAPI 3 only.

Install from NPM: npm install openfetch

Usage

import * as openfetch from 'openfetch';

// Build an API based on the spec. Shown below are the default options:
const api = openfetch.create(SPEC, {
  // The base URL from which to make requests.
  url,
  // Enable logging. Validation errors will be logged to the console.
  logging: false,
  // The console, providing the log methods (only `warn` is used).
  console: window.console,
  // The default implementation of fetch to use for making requests.
  fetch: window.fetch,
});

// If your spec is hosted, it can be retrieved automatically.
const api = await openfetch.hosted('http://example.com', {
  // ... same opts as above
});

// Create an invocation context with credentials and such. The keys of the credentials
// object are names of security schemes, and the values are their values...
// *   HTTP Basic Auth expects the value to be `{ user, pass }`
// *   HTTP Bearer Auth expects the value to be just the token (i.e. not including the "Bearer" prefix)
// *   Other HTTP auth expects the full header value (i.e. including the scheme name)
// *   OAuth2 will pass the token via Autorization header
const invoke = openfetch.client({
  // Override the base URL from which to make requests
  url,
  // Override the implementation of `fetch` again. This value takes precedence over the one
  // passed to `create`, if both were provided.
  fetch,
  // The credentials to use to satisfy security requirements
  credentials: {},
});

// Invoke an operation by `operationId` (here: `getUser`):
// *   Parameter are supplied by name
// *   Options are the same as fetch, with a few being supplied automatically:
//     *   `Content-Type` will be determined automatically if the spec only defines one request body
//         type, otherwise it must be supplied via `headers`.
//     *   If `Content-Type` is JSON, `body` will be passed through `JSON.stringify`.
//         No processing will be done to any other bodies.
//     *   The `Authorization` header will be set automatically based on the security requirements.
//     *   Set the `Accept` header manually to specify which response format to receive.
const response = await invoke(api.getUser({ id: 'foxfriends' }, { headers, body }));

// The response is whatever is returned by the provided implementation of `fetch`. Refer to the
// relevant documentation on how to handle that response. In particular:
// *   The response body is not interpreted at all (e.g. JSON is not parsed automatically)
// *   The response status is not interpreted at all (e.g. 4XX/5XX reponses do not throw)
console.assert(response instanceof Response)

Points to note:

• This package assumes your OpenAPI spec is valid/correct, and that you are (for the most part) calling it with sensible values. Undefined behaviour will occur if you deviate from spec.
• The servers field of the spec is ignored. Provide a correct url on your own.
• There is currently no support for any extensions, but to be able to implement those as plugins is something that is being considered.

Testing

So far... very little testing has been done. Just a bit of manual stuff. Trust this project at your own risk for now, until I feel like writing a proper test suite.

Contributing

Contributions are welcome! Please send a PR or create issues if you would like something improved.