Node 编码规范

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Node.js 规范主要包含编码风格、安全规范, 其中编码风格 参考 eslint-config-egg (opens new window)。

1. 编码风格

• 1.1.【推荐】使用 Node.js 内置的全局变量。来源 : node/prefer-global (opens new window)

/* bad */
/*eslint node/prefer-global/buffer: [error]*/

const { Buffer } = require("buffer")
const b = Buffer.alloc(16)

/* good */
/*eslint node/prefer-global/buffer: [error]*/

const b = Buffer.alloc(16)

/* bad */
/*eslint node/prefer-global/url: [error]*/

const { URL } = require("url")
const u = new URL(s)

/* good */
/*eslint node/prefer-global/url: [error]*/

const u = new URL(s)

• 1.2.【推荐】使用 Node.js promise API。

/* bad */
/*eslint node/prefer-promises/dns: [error]*/
const dns = require("dns")

function lookup(hostname) {
    dns.lookup(hostname, (error, address, family) => {
        //...
    })
}

/*eslint node/prefer-promises/dns: [error]*/
import dns from "dns"

function lookup(hostname) {
    dns.lookup(hostname, (error, address, family) => {
        //...
    })
}

/* good */
/*eslint node/prefer-promises/dns: [error]*/
const { promises: dns } = require("dns")

async function lookup(hostname) {
    const { address, family } = await dns.lookup(hostname)
    //...
}

/*eslint node/prefer-promises/dns: [error]*/
import { promises as dns } from "dns"

async function lookup(hostname) {
    const { address, family } = await dns.lookup(hostname)
    //...
}

• 1.3.【推荐】模块引用声明放在文件顶端、引用顺序。🔒 来源 eslint 规则: import/order (opens new window)

/* bad */
import _ from 'lodash';
import path from 'path'; // `path` import should occur before import of `lodash`

// -----

var _ = require('lodash');
var path = require('path'); // `path` import should occur before import of `lodash`

// -----

var path = require('path');
import foo from './foo'; // `import` statements must be before `require` statement

/* good */

import path from 'path';
import _ from 'lodash';

// -----

var path = require('path');
var _ = require('lodash');

// -----

// Allowed as ̀`babel-register` is not assigned.
require('babel-register');
var path = require('path');

// -----

// Allowed as `import` must be before `require`
import foo from './foo';
var path = require('path');

• 1.4.【推荐】抛出错误异常，使用原生 Error 对象

/* bad */
throw 'error'

throw null

throw undefined

/* good */
throw new Error()

throw new Error('error reason')

const err = new Error()
throw err