@jaris/core

@jaris/core

jaris is still in very early alpha, production usage is not recommended

Jaris. A 0 dependency, functional (phoenix) inspired, node / typescript web framework.

Installation

$ npm install -S @jaris/core

Usage

The core concept behind jaris is that the conn object gets passed through a series of functions (middleware), and the final resulting conn determines what is sent.

The conn object should never be mutated directly, only copied via spread (...conn), or modified using one of the conn helper functions provided.

A simple hello world would look like:

import server, { text } from '@jaris/core';

server([conn => text('Hello, world!', conn)]);

An example using multiple middleware would look like:

import server, { text } from '@jaris/core';

server([
  (conn) => ({
    ...conn,
    body: 'I will be overwritten',
  }),
  (conn) => text('Hello, world!', conn),
  (conn) => {
    console.log('I dont modify the connection at all, I just do some logging'),
    return conn;
  }
])

Since the conn object is simply modified to achieve a response, and all of the response helper functions provided by jaris are automatically curried, we can combine them using the pipe helper:

import server, { json, status, header } from '@jaris/core';
import { pipe } from '@jaris/util';

server([
  conn =>
    pipe(
      status(200),
      header('X-Custom', 'my value'),
      json({ ok: true }),
    )(conn),
]);

Which becomes even more useful when you start making re-usable responses

import server, { json, status, header } from '@jaris/core';
import { pipe } from '@jaris/util';

const formErrors = (errors: any) =>
  pipe(
    status(422),
    json({ errors }),
  );

server([
  conn =>
    formErrors({
      name: 'is required',
    })(conn),
]);

A simple request-time example:

import server, { header } from '@jaris/core';
import { pipe } from '@jaris/util';

const currentTimestamp = () => Math.round((new Date()).getTime() / 1000);

server([
  conn => header('X-Start-Time', `${currentTimestamp()}`, conn),
  conn => {
    // ...perform some relatively long task
    return conn;
  },
  conn => {
    const startTime = parseInt(conn.headers['X-Start-Time']);
    const endTime = currentTimestamp();

    return pipe(
      header('X-End-Time', `${endTime}`)
      header('X-Total-Time', `${endTime - startTime} seconds`)
    )(conn);
  }
]);