Build an interactive CLI with Node.js

Node.js could be very helpful in terms of constructing command-line interfaces (CLIs). In this put up, I am going to train you the best way to use Node.js to construct a CLI that asks some questions and creates a file primarily based on the solutions.

Get began

Let’s begin by making a model new npm bundle. (Npm is the JavaScript bundle supervisor.)

mkdir my-script
cd my-script
npm init

Npm will ask some questions. After that, we have to set up some packages.

npm set up --save chalk figlet inquirer shelljs

Here’s what these packages do:

• Chalk: Terminal string styling achieved proper
• Figlet: A program for making giant letters out of strange textual content
• Inquirer: A group of frequent interactive command-line person interfaces
• ShellJS: Portable Unix shell instructions for Node.js

Make an index.js file

Now we’ll create an index.js file with the next content material:

#!/usr/bin/env node
const inquirer = require("inquirer");
const chalk = require("chalk");
const figlet = require("figlet");
const shell = require("shelljs");

Plan the CLI

It’s all the time good to plan what a CLI must do earlier than writing any code. This CLI will do only one factor: create a file.

The CLI will ask two questions—what’s the filename and what’s the extension?—then create the file, and present successful message with the created file path. 

// index.js
const run = async () => ;
run();

The first operate is the script introduction. Let’s use chalk and figlet to get the job achieved.

const init = () => 

  console.log(

    chalk.inexperienced(

      figlet.textSync("Node JS CLI", )

    )

  );
const run = async () => ;
run();

Second, we’ll write a operate that asks the questions.

const askQuestions = () => ;
// ...
const run = async () => ;

Notice the constants FILENAME and EXTENSIONS that got here from inquirer.

The subsequent step will create the file.

const createFile = (filename, extension) => ;
// ...
const run = async () => ;

And final however not least, we’ll present the success message together with the file path.

const success = (filepath) => 

  console.log(

    chalk.white.bgGreen.daring(`Done! File created at $`)

  );
;
// ...
const run = async () => ;

Let’s check the script by operating node index.js. Here’s what we get:

The full code

Here is the ultimate code:

#!/usr/bin/env node
const inquirer = require("inquirer");
const chalk = require("chalk");
const figlet = require("figlet");
const shell = require("shelljs");
const init = () => ;
const askQuestions = () => 
  const questions = [
    
      title: "FILENAME",
      kind: "input",
      message: "What is the name of the file without extension?"
    ,
    
  ];
  return inquirer.immediate(questions);
;
const createFile = (filename, extension) => 
  const filePath = `$/$filename.$extension`
  shell.contact(filePath);
  return filePath;
;
const success = filepath => ;
const run = async () => ;
run();

Use the script anyplace

To execute this script anyplace, add a bin part in your bundle.json file and run npm hyperlink.

Running npm hyperlink makes this script out there anyplace. 

That’s what occurs whenever you run this command:

/usr/bin/creator -> /usr/lib/node_modules/creator/index.js
/usr/lib/node_modules/creator -> /residence/hugo/code/creator

It hyperlinks the index.js file as an executable. This is barely potential due to the primary line of the CLI script: #!/usr/bin/env node.

Now we are able to run this script by calling:

$ creator

Wrapping up

As you may see, Node.js makes it very simple to construct good command-line instruments! If you wish to go even additional, test this different packages:

• meow – a easy command-line helper
• yargs – a command-line opt-string parser
• pkg – bundle your Node.js venture into an executable

Tell us about your expertise constructing a CLI within the feedback.