express-msgpack
Version:
Transparent MessagePack middleware for Express
98 lines (71 loc) • 4.25 kB
Markdown
# Express Msgpack
[](https://github.com/textbook/express-msgpack/blob/main/LICENSE)
[](https://github.com/textbook/express-msgpack/actions)
[](https://codeclimate.com/github/textbook/express-msgpack/test_coverage)
[](https://codeclimate.com/github/textbook/express-msgpack/maintainability)
[](https://www.npmjs.com/package/express-msgpack)
[Express] and [MessagePack], together at last. Uses [`@msgpack/msgpack`][1] by default.
## Functionality
Provides transparent middleware that can be used to support clients requesting
`Accept: application/msgpack` from endpoints using `res.json` or sending
`Content-Type: application/msgpack` to any endpoint. You can continue to use
`req.body` and `res.json` and `expressMsgpack` will handle the conversion in
the background using `@msgpack/msgpack` (or any compatible library of your
choice).
## Installation
```bash
$ npm install --save express-msgpack
// or
$ yarn add express-msgpack
```
If you intend to use an alternative to `@msgpack/msgpack` (see Configuration)
you can add the `--no-optional` flag; it's an optional dependency.
## Usage
```javascript
import msgpack from "express-msgpack";
// ...
app.use(msgpack());
```
### CommonJS
```javascript
const msgpack = require("express-msgpack").default;
// ...
app.use(msgpack());
```
## Configuration
To configure, pass options when you configure the middleware. Currently supported options are:
| Parameter | Description | Default |
|------------|----------------------------------------------------------|------------------------------------------------------------------------------|
| `decoder` | a function converting from MessagePack to JavaScript | `@msgpack/msgpack#decode` |
| `encoder` | a function converting from JavaScript to MessagePack | `@msgpack/msgpack#encode` (with a wrapper to convert the result to a Buffer) |
| `mimeType` | the MIME type to detect and set for MessagePack payloads | `"application/msgpack"` |
| `limit` | The byte limit of the body. This is the number of bytes or any string format supported by [bytes](https://www.npmjs.com/package/bytes) | `"100kb"` |
For example, to switch to the node-gyp C++ based [msgpack] library:
```javascript
import msgpack from "express-msgpack";
import { pack, unpack } from "msgpack";
// ...
app.use(msgpack({ decoder: unpack, encoder: pack }));
```
## Development
The project has code linting and testing, using the following commands:
- `npm run e2e`: run the smoke/E2E tests
- `npm run lint`: run the ESLint checks
- `npm run ship`: lint and run unit, integration and E2E tests
- `npm test`: run the Jest unit and integration tests
- `npm test:watch`: run the tests in watch mode
The tests are in the `__tests__/` directory and are run using [Jest]. They're
split into two files:
- `unit.test.ts` - mockist unit tests, to check specific internal details
- `integration.test.ts` - integration tests using [SuperTest] with a simple
Express app using the middleware
There is also a `smoke/` directory containing E2E/smoke tests for a deployed
version of the package, used by `bin/smoke.sh`. If the `--local` argument is
supplied to the script the local version is packaged and tested , otherwise
the specified `$TAG` version is installed from the registry and tested.
[Express]: https://expressjs.com/
[Jest]: https://jestjs.io/
[MessagePack]: https://msgpack.org/
[msgpack]: https://www.npmjs.com/package/msgpack
[SuperTest]: https://github.com/visionmedia/supertest
[1]: https://www.npmjs.com/package/@msgpack/msgpack