Nestjs Console

Create beautiful CLI commands in your application. A simple NestJS CLI module, comes packaged with utilities.

Table Of Content

• Features
• Installation
• Getting Started
• Creating Command
  • Class
  • Method
• Defining Input
  • Arguments
  • Options
• Command Console I/O
  • Retrieving Inputs
  • Prompting for Input
  • Writing Outputs
• Available Commands
• Available Options
• Contributing
• About Us
• License

Features

• Quick Setup - Quickly setup and configure your application

• Utilities - Comes packed with utilities to let you easily interact and print.

• Beautiful Commands - Creating a beautiful command is as easy as creating a simple injector.

Installation

To install the package, run

npm install @squareboat/nest-console

OR

yarn add @squareboat/nest-console

For NestJS v6.7.x, please use

npm install @squareboat/nest-console^0.0.7

Getting Started

Once the cli file is copied, you need to open the cli file and change the module that you need to pass in createApplicationContext method.

If you are following the default project structure created by nest command. You don't need to do anything.

Once the added the correct module in cli file, you need to import the ConsoleModule from the package.

import { Module } from "@nestjs/common";
import { ConsoleModule } from "@squareboat/nest-console";
import { AppController } from "./app.controller";
import { AppService } from "./app.service";

@Module({
  imports: [ConsoleModule],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

Now, whatever command you create in your application will be discovered automatically.

To be able for the package to discover the command, you need to register the Injectable class inside providers property in your module.

Creating Command

There are basically two ways through which you can define commands.

• Using the Command decorator on an Injectable class
• Using the Command decorator on an Injectable class' method.

Remember to use the @Injectable decorator on the class always a, else the command will not be discovered and registered.

Class

You can create an injectable class and use @Command decorator on it. The package will automatically look for handle method inside the class.

Method

You can use @Command decorator on the method.

import { Injectable } from "@nestjs/common";
import { Command, ConsoleIO } from "@squareboat/nest-console";

@Injectable()
export class AppService {
  @Command("hello {name=world}", { desc: "Test Command" })
  sayHello(_cli: ConsoleIO) {
    const name = _cli.argument<string>("name");
    _cli.info(`Hello ${name}!`);
    return;
  }
}

Before running the command, you need to build it first.

npm run build

Now, to run any command, you can simply do

node cli hello

Defining Input

We understand that you may want to build commands which can be dynamic in nature, ie. you may expect some required or optional parameters from client while running the command. We have made it dead simple for you to define your input expectations.

All user supplied arguments and options are wrapped in curly braces.

Arguments

Arguments in console applications are required variables.

@Command(
  'generate:report {type}',
  { desc: 'Test Command' }
)

$ node cli generate:report gar

Options

Options are the optional inputs for each command. They are denoted by double hyphens (--).

Example:

@Command(
  'generate:report {type} {--emails}',
  {  desc: 'Test Command',}
)

$ node cli generate:report gar [email protected]

To pass array of values in any options or arguments, you can add asterik.

generate:report {type*} {--emails*}

$ node cli generate:report gar gmr [email protected] [email protected]

You can also define default values for the arguments or options by adding a = equal sign followed by the value.

generate:report {type=gar} {--emails=email@example.com}

---

Retrieving Inputs

We provide easy to use APIs to work with I/O directly from the console.

Retrieving Passed Inputs

While executing command, you will need to fetch the values that you may have passed in the invocation. Your method will be passed an _cli: ConsoleIO object. You can then simply check for all the values.

For fetching an argument, you can do

const type = _cli.argument<string>("type");

For fetching an option, you can do

const email = _cli.option<string>("email");

If no value is passed, the argument and option function will return the default value or null value.

Prompting for Input

You may want to ask for input while executing a command. We provide several ways with which you can ask for inputs directly on console.

To ask for simple input from the user, you can call ask(question: string) method.

const name = _cli.ask("name");

You may want to ask user about some secret or any password, which ideally should not get printed on the console.

const password = await _cli.password("Enter your pasword to continue");

While running a command, you can also give choices to select from a defined list. For example:

/**
 * Single choice example.
 * Returns one of the passed choices.
 */
const choice = await _cli.select(
  "Please select one superhero", // question
  ["Batman", "Ironman"], // choices
  false // multiple?
);

/**
 * Multiple choices example.
 * Returns an array of the selected options.
 */
const choice = await _cli.select(
  "Please select one superhero",
  ["Batman", "Ironman"],
  true
);

Lastly, sometimes you may want to ask for confirmation from the user before doing any execution. You can do so by using confirm method.

const confirm = await _cli.confirm("Do you really wish to continue?");
if (confirm) {
  // do your magic here
}

Writing Outputs

Till now, we have seen how we can operate with differnt type of inputs on the cli. There will be scenarios when you will want to print something on the console. We provide a very easy-to-use set of APIs for your basic console outputing needs.

To print any message on the console, use info method

_cli.info("Some amazing message"); // Outputs 'Some amazing message' on the console

Incase of an error message, use error method.

_cli.error("Oops! Something went wrong.");

Similarly, to print any success message, use success method

_cli.success("Wohoo! The command worked just fine!");

To print a divider on the console, simple do

_cli.line();

To print a table on the console, you can use table method:

// this will automatically print unicode table on the console
_cli.table([
  { name: "User 1", designation: "Software Engineer L1" },
  { name: "User 2", designation: "Software Engineer L1" },
]);

---

Available Commands

We provide few commands, which will help in your day to day development process.

To list all commands available in your application, you can do

node cli list

list is a reserved command name, please don't use it in any of the commands

---

Available Options

We provide few out-of-the-box predefined options, which you can use with each of your command.

To list all the arguments and options that your command supports/expects, simply run

node cli users:greet --options

--options is a reserved option. Please don't use it anywhere in your command

Contributing

To know about contributing to this package, read the guidelines here

About Us

We are a bunch of dreamers, designers, and futurists. We are high on collaboration, low on ego, and take our happy hours seriously. We'd love to hear more about your product. Let's talk and turn your great ideas into something even greater! We have something in store for everyone. ☎️ 📧 Connect with us!

We are hiring! Apply now at careers page

License

The MIT License. Please see License File for more information. Copyright © 2020 SquareBoat.

Made with ❤️ by Squareboat