Why encapsulate an NPM package for a utility function?

When you write multiple Node applications in succession and want console to look nice, you might encapsulate a function like this

import chalk from "chalk";

function noop(msg: string): string {
    return msg
}

function log(fn: Function): (msg: string) => void {
    return (msg: string): void => {
        console.log(fn(msg));
    };
}

export default {
    success: log(chalk.green),
    error: log(chalk.red),
    warn: log(chalk.yellow),
    info: log(chalk.cyan),
    log: log(noop)
};
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Call way

import log from './log'
log.success("hello green message!")
log.error("hello red message!")
log.warn("hello yellow message!")
log.info("hello cyan message!")
log.log("hello normal message!")
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Slowly discovered that every project needs such a log file, yes! We can now consider these commonly used functions encapsulated in an NPM package!

What do you need to pay attention to

Unit testing

Considering the increase in code volume and the increase in contributors, it is necessary to include unit tests beforehand

  • Test Framework – Mocha is a rich Javascript test framework that runs in Node.js and browsers and supports BDD, TDD, QUnit, and Exports tests
  • Assertion library – Assert is shipped with Node

Continuous integration

Travis CI provides Continuous Integration, or CI. It is tied to projects on Github and automatically grabs new code whenever it comes in. Then, provide a running environment, perform tests, complete the build, and deploy to the server.

The code level

Extend open to modify the design principles of close

When a utility file is added to the SRC directory, index.ts is automatically captured and mounted on module.export

Use the getter to implement the lazy export function

Object.defineProperty(module.export, 'log', {
    configurable: false,
    enumerable: true,
    get: () => require('./log')});Copy the code

The project address

Github.com/xiaoxiaojx/… Welcome 🌟 Star 🌟 and Pr and use ~ in projects