@everestate/serverless-router

@everestate/serverless-router

Serverless, minimalist, pluggable, universal router.

Installation

npm install @everestate/serverless-router --save

Usage

To use serverless-router you will need at least one of its plugins.

• serverless-router-aws
• serverless-router-dynamics
• serverless-router-event
• and others

const Router = require('@everestate/serverless-router');
const { HTTP } = require('@everestate/serverless-router-aws');

cosnt userService = require('../services/userService');

function dispatch(event) {
  const router = new Router([HTTP]);

  router.http
    .post('/users', () =>
      userService.createUser(event.body)) // returns promise
    .get('/users/:id', () =>
      userService.getUserById(event.pathParameters.id)) // returns promise
    .patch('/users/:id', () =>
      userService.updateUser(event.pathParameters.id, event.body)) // returns promise
    .delete('/users/:id', () =>
      userService.deleteUser(event.pathParameters.id)); // returns promise

  router.mismatch(() => {
    const { path, httpMethod } = event;
    return Promise.reject(new Error(`Unknown route: ${httpMethod} ${path}`));
  });

  return router.dispatch(event);
}

function myLambdaHandler(event, context, callback) {
  return dispatch(event)
    .then(result =>
      callback(null, { statusCode: result.code, body: JSON.stringify({ payload: result.payload }) }))
    .catch(error =>
      callback(null, { statusCode: '500', body: JSON.stringify({ message: error.message }) }));
}

When route is mismatched

By default serverless-router will throw error on route mismatch.

It's possible to define a custom mismatch handler, and it would be called with same arguments as dispatch was called:

router.mismatch((event, context, callback) => {
  const { path, httpMethod } = event;
  return callback(null, {
    statusCode: '404',
    body: JSON.stringify({ message: `ServerlessRouter can't find the route ${httpMethod} ${path}` }),
  });
});

Middleware

When middleware are set, they will be called before each matched route in order they registered. Middleware callback is expected to return Promise and could be defined with use:

router.use((event, context, callback) => {
    const { source } = event;
    if (source === 'bad source') {
        return Promise.reject(new Error('Bad event source'));
    }
    return Promise.resolve();
})

Plugins

Check the docs/plugins.md to find out how to implement the new plugin.

License

MIT