一個簡單的終端機待辦表小程式。

todolist.js

const rl = require("readline").createInterface({
    input: process.stdin,
    output: process.stdout,
})
const path = require("path")
const fs = require("fs")



const SAVE_PATH = path.join(__dirname, "./save.txt")



/** @returns {Promise<String>} */
const interactive = que =>
    new Promise(resolve => rl.question(que + "\n", resolve))



const File = (() => {
    const basicMethod = {
        /** @returns {Promise<[{id: Int, time: Int, data: String, done: Boolean}]>} */
        read: () => new Promise((resolve, reject) =>
            fs.readFile(SAVE_PATH, (err, data) => err
                ? reject(err)
                : resolve(JSON.parse(data)))),

        /** @returns {Promise<[{id: Int, time: Int, data: String, done: Boolean}]>} */
        write: content => new Promise(resolve =>
            fs.writeFile(SAVE_PATH, JSON.stringify(content), () => resolve(content))),
    }

    const append = content => {
        const maxId = list => Math.max(...list.map(({ id }) => id))

        const pushToLast = val => list => [
            ...list, (val.id = maxId(list) + 1, val)
        ]

        return basicMethod.read()
            .then(pushToLast(content))
            .then(basicMethod.write)
    }

    const map = func => basicMethod.read()
        .then(list => list.map(func))
        .then(basicMethod.write)

    return {
        ...basicMethod, append, map,
    }
})()



const Data = {
    init: val => ({ time: new Date().getTime(), data: val, done: false, }),

    /** @returns {String} */
    show: fileContent => fileContent.length === 0
        ? "Empty."
        : fileContent
            .map(({ time, data, done, id }) =>
                `${done ? "[v]" : "[ ]"} [${id}]: ${data}\n\tat: ${new Date(time).toLocaleString()}`)
            .join("\n")
}



const Parm = (() => {
    const helpIntro = `
Hi, this is a simple todo list cli app.
Here have some function for you, try it out!

    add     <string> : add a todo in your list.
    del     <int?>   : delete a todo that id is equal your parm.
                     : if didn't send any number to me, than I will delete all the list.
    lok              : display your todo list.
    finish  <int>    : set a todo item are finish.`

    const alog = todoList => Promise
        .resolve(console.log("\n" + Data.show(todoList)))

    const method = {
        add: content => content
            ? Promise.resolve(Data.init(content))
                .then(File.append)
                .then(alog)

            : Promise.resolve(console.log(
                "You didn't input any content, I can't append that for you.")),

        del: content => content
            ? File.read()
                .then(data => data
                    .filter(({ id }) => id !== Number(content)))
                .then(File.write)
                .then(alog)

            : Promise.resolve(console.log(
                "You realy want to delete all todo list?"))
                .then(() => interactive("If truely, input 'y' or 'Y':"))
                .then(input => input === "y" || input === "Y"
                    ? File.write([])
                        .then(() => console.log(
                            "Ok, now you have a new todo list."))
                    : console.log("Ok, I willn't change anything.")),

        lok: () => File.read()
            .then(alog),

        finish: val => !Number.isNaN(Number(val))
            ? File.map(todo => todo.id === Number(val)
                ? (todo.done = true, todo)
                : todo)
                .then(alog)

            : Promise.resolve(console.log(
                "Your parm isn't a number, so I not sure what are your want.")),

        help: () => Promise.resolve(console.log(helpIntro)),
    }

    return {
        check: ([execute, ...content]) =>
            (method[execute] || method.help)(content.join(" "))
    }
})()



const main = (nodePath, filePath, ...userVals) =>
    Parm.check(userVals)
        .finally(() => rl.close())

main(...process.argv)