Node practical development of a mycli command line tool

For initialization,

you must first ensure that there is a node.js environment on the computer

and execute the following code on the command line to initialize a package.json file

npm init -y

. At this time, an error will definitely be reported when executing mycli on the command line.

Configure the custom command

package.json to add the bin field, and associate mycli command.

• Each command corresponds to an executable file

"bin": {
    "mycli": "./test.js"
  },

• Create a new /test.js file

console.log ("mycli command executed successfully");

• the install command is required, but the project has not been published to npm, so for the time being, use the npm link command to associate mycli command to the global world.

At this time, if you execute mycli from the command line, the error will no longer be reported.

Script configuration

test.js file:

console.log("mycli command execution successful");

Then execute mycli , and an error pop-up window will appear.

This is because when executing the mycli command, it is equivalent to letting the computer execute the file, and the computer system cannot directly execute the js file . This requires us to add a configuration to the first line of the script code to specify node.js on the computer. program to execute this js script file.

#!/usr/bin/env node

Because the execution environment has been changed, you need to delete the previously linked files. The file location may be C:Program Filesnodejsnode_modules . Find mycli and delete it, and then execute npm link again.

Now execute mycli on the console again, and you can see that the console prints correctly.

The related toolkit uses

• the Chalk command line to output colorful fonts
• Ora loading effect, similar to the progress library
• commander design command
• inquirer interactive function (such as: ask questions...)

Chalk

• installation

npm install [email protected] -S

• Use test.js

const chalk = require("chalk");

// chalk
// const hello = chalk.red("hello");
// const hello = chalk.blue.bgRed("hello");
// const hello = chalk.blue.bgYellow("hello");
const hello = chalk.rgb(200, 200, 200).bgRgb(0, 200, 3)("hello");
console.log(hello);

Ora

• installation

npm install [email protected] -S

• use test.js

const ora = require("ora");

// ora
const spinner = ora({
  text: "Installing..."
});
spinner.start();
setTimeout(() => {
  // spinner.stop();
  spinner.succeed("Installation successful");
  // console.log("Installation successful");
}, 2000)

• Commonly used api
  • start starts loading
  • stop stops loading
  • succeed ends loading with successful style

commander

development, such as vue -V git --version vue create and other commands, need to use the commander library to implement such commands.

-V --help , etc. after the command used can be understood as the parameters of the command. Then we need to obtain these parameters and handle different events by judging the differences in parameters.

In the node environment, this parameter can be obtained through process.argv . The commander library helps us encapsulate some methods without us having to judge the instructions carried by the user's input.

• Install

npm install [email protected] -S

• using

const commander = require("commander");
// ...
commander.parse(process.argv); // After

the installation is completed, commander will automatically provide us with some commands, such as --help . Let's test it below:

mycli --help

• provides a way to set the version number

commander. version("1.0.0");

Execute mycli -V and you can see that the console prints the 1.0.0 version number.

The custom command method

commander.option(指令名, 描述, 回调函数)

• configures some of the functions written above to the --init command:

commander.option("--init", "this is init", () => {
  // chalk
  // const hello = chalk.red("hello");
  // const hello = chalk.blue.bgRed("hello");
  // const hello = chalk.blue.bgYellow("hello");
  const hello = chalk.rgb(200, 200, 200).bgRgb(0, 200, 3)("hello");
  console.log(hello);

  // ora
  const spinner = ora({
    text: "Installing..."
  });
  spinner.start();
  setTimeout(() => {
    // spinner.stop();
    spinner.succeed("Installation successful");
    // console.log("Installation successful");
  }, 1000)
})

Now execute mycli --init test:

• The way to pass parameters in the command

is commander.option("--number <num>", "log a number", (num) => {
  console.log(num);
})

<参数名> indicates the parameters that must be passed, and [参数名] indicates the parameters that are not required to be passed. Enter mycli --number 100 on the console and press Enter. You can see 100 will be output.

Custom command method

commander.command("create <projectName>").action((projectName)=>{
  console.log(projectName);
})

Execute mycli create xx and press Enter. You can see xx is output on the console.

View the help

by executing mycli --help . You can see that the instructions and commands we just configured appear in the help list.

inquirer

• installation

npm install inquirer -S

• prompt method to ask

inquirer.prompt([
    {
      type: "input",
      name: "username",
      message: "Please enter username:"
    }
  ]).then((answer)=>{

  })

type indicates the type of question, and the value may be: input , number , password , editor , etc.

answer is {username: 输入的值}

• type is input of input type

const inquirer = require("inquirer");

commander.command("add user").action(() => {
  inquirer.prompt([
    {
      type: "input",
      name: "username",
      message: "Please enter username:"
    }
  ]).then((answer) => {
    console.log(answer);
  })
})

• type is confirm

commander.command("testcon").action(() => {
  inquirer.prompt([
    {
      type: "confirm",
      name: "age",
      message: "Are you over 18 years old?"
    }
  ]).then((answer) => {
    console.log(answer);
  })
})

Enter y or n to make a judgment.

• type is a radio selection type list

commander.command("testlist").action(() => {
  inquirer.prompt([
    {
      type: "list",
      name: "lib",
      message: "Select the framework to use:",
      choices: [
        "vue2",
        "vue3",
        "react",
        "svelte",
      ]
    }
  ]).then((answer) => {
    console.log(answer);
  })
})

Execute the mycli testlist command:

Download template

• download-git-repo is a tool for pulling code.

• Install

npm install [email protected] -S

• using

const downgit = require("download-git-repo");

downgit("github:kongcodes/vue3-vant", downUrl, { clone: ​​false }, function (err) {
    console.log(err)
})

The first parameter in the downgit method is understood to be downloading the kongcodes user's vue3-vant project template from github. The second parameter downUrl is the directory to which the template should be downloaded. The third parameter clone is whether to use git clone to download. The fourth parameter is some things to be executed when the download is completed.

• command

commander.command("create <projectName>").action((projectName) => {

  const spinner = ora({
    text: "Downloading https://github.com/kongcodes/vue3-vant..."
  });
  spinner.start();
  fs.mkdirSync(`./${projectName}`);
  const downUrl = `${process.cwd()}\${projectName}`;
  downgit("github:kongcodes/vue3-vant", downUrl, { clone: ​​false }, function (err) {
    if (err) throw err;
    spinner.stop();
    console.log(chalk.green("downgit success"));
  })
})

Execute mycli create pro and press Enter. The pro directory will be created in the current directory and vue3-vant template will be downloaded to this directory.

Code address

https://github.com/kongcodes/mycli