30个有用的npm包

const qs = require('qs');
constv assert = require('assert');

const obj = qs.parse('a=c');
assert.deepEqual(obj, { a: 'c' });

const str = qs.stringify(obj);
assert.equal(str, 'a=c');

const { range } = require('rxjs');
const { map, filter } = require('rxjs/operators');
range(1, 200).pipe(
  filter(x => x % 2 === 1),
  map(x => x + x)
).subscribe(x => console.log(x));

import mitt from 'mitt'
const emitter = mitt()
emitter.on('foo', e => console.log('foo', e) )
emitter.on('*', (type, e) => console.log(type, e) )
emitter.emit('foo', { a: 'b' })
emitter.all.clear()

function onFoo() {}
emitter.on('foo', onFoo)   // listen
emitter.off('foo', onFoo)  // unlisten

const _ = require(“underscore);
const list = [[5, 1, 7], [3, 2, 1]];
_.invoke(list, 'sort');
// => [[1, 5, 7], [1, 2, 3]]

const dayjs = require(“dayjs”);
dayjs().startOf('month').add(1, 'day').set('year', 2018).format('YYYY-MM-DD HH:mm:ss');

import * as R from 'ramda';
const double = x => x * 2;
R.map(double, [1, 2, 3]); 
// => [2, 4, 6]
R.map(double, {x: 1, y: 2, z: 3}); 
// => {x: 2, y: 4, z: 6}

var validator = require('validator');
validator.isEmail('foo@bar.com'); //=> true

import * as yup from 'yup';
let schema = yup.object().shape({
  name: yup.string().required(),
  age: yup.number().required().positive().integer(),
  email: yup.string().email(),
  website: yup.string().url(),
  createdOn: yup.date().default(function () {
    return new Date();
  }),
});
// check validity
schema
  .isValid({
    name: 'jimmy',
    age: 24,
  })
  .then(valid => 
    console.log(valid) // => true
  );
// you can try and type cast objects to the defined schema
schema.cast({
  name: 'jimmy',
  age: '24',
  createdOn: '2014-09-23T19:25:25Z',
});
// => { name: 'jimmy', age: 24, createdOn: Date }

const _ = require("lodash");
const nums = _.range(1, 9);
// => [1, 2, 3, 4, 5, 6, 7, 8, 9]
const chunks = _.chunk(nums, 3);
// => [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
const right = _.takeRight(nums, 2);
// => [7, 8, 9]

import { format, formatDistance, formatRelative, subDays } from 'date-fns'
format(new Date(), '[Today is a] dddd')
//=> "Today is a Wednesday"
formatDistance(subDays(new Date(), 3), new Date())
//=> "3 days ago"
formatRelative(subDays(new Date(), 3), new Date())
//=> "last Friday at 7:26 p.m."

const jwt = require('jsonwebtoken');
const token = jwt.sign({ foo: 'bar' }, 'shhhhh');

const { v4: uuidv4 } = require('uuid');
uuidv4(); // => '1a68a438-b077-468b-b1e8-dcdd976a0f5b'

const rimraf = require(“rimraf”);
rimraf('./build', error => {
  if (error) console.error(error);
});

const fs = require(‘fs-extra’);
async function copyFiles () {
  try {
    await fs.copy('/tmp/myfile', '/tmp/mynewfile');
    console.log('success!');
  } catch (err) {
    console.error(err);
  }
}
copyFiles();

const mkdirp = require('mkdirp')
// return value is a Promise resolving to the first directory created
mkdirp('/tmp/foo/bar/baz').then(made =>
  console.log(`made directories, starting with ${made}`));

const glob = require("glob");
// options is optional
glob("**/*.js", options, function (er, files) {
  // files is an array of filenames.
  // If the `nonull` option is set, and nothing
  // was found, then files is ["**/*.js"]
  // er is an error object or null.
});

const shell = require('shelljs');
if (!shell.which('git')) {
  shell.echo('Sorry, this script requires git');
  shell.exit(1);
}
// Copy files to release dir
shell.rm('-rf', 'out/Release');
shell.cp('-R', 'stuff/', 'out/Release');
// Replace macros in each .js file
shell.cd('lib');
shell.ls('*.js').forEach(function (file) {
  shell.sed('-i', 'BUILD_VERSION', 'v0.1.2', file);
  shell.sed('-i', /^.*REMOVE_THIS_LINE.*$/, '', file);
  shell.sed('-i', /.*REPLACE_LINE_WITH_MACRO.*\n/, shell.cat('macro.js'), file);
});
shell.cd('..');
// Run external tool synchronously
if (shell.exec('git commit -am "Auto-commit"').code !== 0) {
  shell.echo('Error: Git commit failed');
  shell.exit(1);
}

const yaml = require('js-yaml');
const fs   = require('fs');
// Get document, or throw exception on error
try {
  const doc = yaml.load(fs.readFileSync('/home/ixti/example.yml', 'utf8'));
  console.log(doc);
} catch (e) {
  console.log(e);
}

const Koa = require('koa');
const app = new Koa();

app.use(async ctx => {
  ctx.body = 'Hello World';
});
app.listen(3000);

const express = require('express');
const app = express();
app.get('/', function (req, res) {
  res.send('Hello World');
});
app.listen(3000);

const fastify = require('fastify')({
  logger: true
});
fastify.get('/', async (request, reply) => {
  reply.type('application/json').code(200);
  return { hello: 'world' };
});
fastify.listen(3000, (err, address) => {
  if (err) throw err;
  fastify.log.info(`App listening on ${address}`);
});

const server = require('http').createServer();
const io = require('socket.io')(server);
io.on('connection', client => {
  client.on('event', data => { /* … */ });
  client.on('disconnect', () => { /* … */ });
});
server.listen(3000);

test('adds 1 + 2 to equal 3', () => {
  expect(1 + 2).toBe(3);
});

interface User {
  name: string;
  id: number;
}
const user: User = {
  name: "Hayes",
  id: 0,
};

const winston = require('winston');
const logger = winston.createLogger({
  level: 'info',
  format: winston.format.json(),
  defaultMeta: { service: 'user-service' },
  transports: [
    // Write all logs with level `error` and below to `error.log`
    new winston.transports.File({ filename: 'error.log', level: 'error' }),
    // Write all logs with level `info` and below to `combined.log`
    new winston.transports.File({ filename: 'combined.log' }),
  ],
});
logger.log({
  level: 'error',
  message: 'Hello distributed log files!'
});
logger.info('Hello again distributed logs');

const debug = require('debug')('http')
  , http = require('http')
  , name = 'My App';
debug('booting %o', name);
http.createServer(function(req, res){
  debug(req.method + ' ' + req.url);
  res.end('hello\n');
}).listen(3000, function(){
  debug('listening');
});

{
    "rules": {
        "semi": ["error", "always"],
        "quotes": ["error", "double"]
    }
}

nodemon ./server.js 

.env file:

DB_HOST=localhost
DB_USER=root
DB_PASS=s1mpl3
require('dotenv').config();
const db = require('db');
db.connect({
  host: process.env.DB_HOST,
  username: process.env.DB_USER,
  password: process.env.DB_PASS
});

{
  "scripts": {
    "start-prod": "cross-env NODE_ENV=production node ./app.js"
  }
}