node-todo-yi/db.js

``` yarn add global node-todo-yi ```

const homedir = require('os').homedir(); //系统home目录
const home = process.env.HOME || homedir;	//环境变量home目录
const fs = require('fs')
const path = require('path')
const dbPath = path.join(home, '.node-todo')

const db = {
	read(path = dbPath) {
		return new Promise((resolve, reject) => {
			fs.readFile(path, {flag: 'a+'}, (error, data) => {
				if (error) {
					return reject(error);
				}
				let list
				try {
					list = JSON.parse(data.toString())
				} catch (e) {
					list = []
				}
				resolve(list)
			})
		})
	},
	write(list, path = dbPath) {
		const string = JSON.stringify(list)
		return new Promise((resolve, reject) => {
			fs.writeFile(path, string + '\n', error => {
				if (error) return reject(error)
				resolve()
			})
		})
	}
}
module.exports = db