/brocli

Modern type-safe way of building CLIs

Primary LanguageTypeScriptApache License 2.0Apache-2.0

BroCLI

Run CLI commands with fully typed handlers

Code

Defining options

Start defining options using string() and boolean functions:

import { string, boolean } from '@drizzle-team/brocli'

const commandOptions = {
    opt1: string(),
    opt2: boolean('flag').alias('f'),
    // And so on... 
}

Keys of the object passed to the object storing options determine to which keys parsed options will be assigned to inside your handler.

Option builder

Initial builder functions:

  • string(name?: string) - defines option as a string-type option which requires data to be passed as --option=value

    • name - name by which option is passed in cli args
      If not specified, defaults to key of this option in defineOptions
      ⚠️ - must not contain = character and be unique per each defineOptions()
      💬 - will be automatically prefixed with - if one character long, -- if longer
      If you wish to have only single hyphen as a prefix on multi character name - simply specify name with it: string('-longname')
  • boolean(name?: string) - defines option as a boolean-type option which requires data to be passed as --option

    • name - name by which option is passed in cli args
      If not specified, defaults to key of this option in defineOptions
      ⚠️ - must not contain = character and be unique per each defineOptions()
      💬 - will be automatically prefixed with - if one character long, -- if longer
      If you wish to have only single hyphen as a prefix on multi character name - simply specify name with it: boolean('-longname')

Extensions:

  • .alias(...aliases: string[]) - defines aliases for option

    • aliases - aliases by which option is passed in cli args
      ⚠️ - must not contain = character and be unique per each defineOptions()
      💬 - will be automatically prefixed with - if one character long, -- if longer
      If you wish to have only single hyphen as a prefix on multi character alias - simply specify alias with it: .alias('-longname')
  • .desc(description: string) - defines description for option to be displayed in help command

  • .required() - sets option as required, which means that application will print an error if it is not present in cli args

  • .default(value: string | boolean) - sets default value for option which will be assigned to it in case it is not present in cli args

  • .hidden() - sets option as hidden - option will be omitted from being displayed in help command

Creating handlers

Normally, you can write handlers right in the command() function, however there might be cases where you'd want to define your handlers separately.
For such cases, you'd want to infer type of options that will be passes inside your handler.
You can do it using TypeOf type:

import { string, boolean, type TypeOf } from '@drizzle-team/brocli'

const commandOptions = {
    opt1: string(),
    opt2: boolean('flag').alias('f'),
    // And so on... 
}

export const commandHandler = (options: TypeOf<typeof commandOptions>) => {
    // Your logic goes here...
}

Defining commands

To define commands, use command() function:

import { command, type Command, string, boolean, type TypeOf } from '@drizzle-team/brocli'

const commandOptions = {
    opt1: string(),
    opt2: boolean('flag').alias('f'),
    // And so on... 
}

const commandHandler = (options: TypeOf<typeof commandOptions>) => {
    // Your logic goes here...
}

const commands: Command[] = []

commands.push(command({
    name: 'command', 
    aliases: ['c', 'cmd'],
    description: 'Description goes here',
    hidden: false,
    options: commandOptions,
    handler: commandHandler,
}));

Parameters:

  • name - name by which command is searched in cli args
    ⚠️ - must not start with - character and be unique per command collection

  • aliases - aliases by which command is searched in cli args
    ⚠️ - must not start with - character and be unique per command collection

  • description - description for command to be displayed in help command

  • hidden - sets command as hidden - if true, command will be omitted from being displayed in help command

  • options - object containing command options created using string() and boolean() functions

  • handler - function, which will be executed in case of successful option parse

💬 - BroCLI starts with having help command predefined, and despite the requirement for command names to be unique, help can actually be redefined so that your app could have it matching your output style instead that of this library's.

Running commands

After defining commands, you're going to need to execute runCli() function to start command execution

import { command, type Command, runCli, string, boolean, type TypeOf } from '@drizzle-team/brocli'

const commandOptions = {
    opt1: string(),
    opt2: boolean('flag').alias('f'),
    // And so on... 
}

const commandHandler = (options: TypeOf<typeof commandOptions>) => {
    // Your logic goes here...
}

const commands: Command[] = []

commands.push(command({
    name: 'command', 
    aliases: ['c', 'cmd'],
    description: 'Description goes here',
    hidden: false,
    options: commandOptions,
    handler: commandHandler,
}));

// And so on...

runCli(commands)

💬 - in case cli arguments are not stored in process.argv in your environment, you can pass custom argument source as a second argument to runCli(), however note that first two elements of such source will be ignored as they are expected to store executable and executed file paths instead of args.

CLI

In BroCLI, command doesn't have to be the first argument, instead it may be contained in any order.
To make this possible, hovewer, string-type options are limited to --option=value syntax.
Options are parsed in strict mode, meaning that having any unrecognized options will result in anerror.