Object orientated, event driven CLI module
Latest commit 2fe87cc Jun 5, 2018


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seeli ( C. L. I. )

Object orientated, event driven , Interactive CLI module. Seeli aims to give you the tools to compose A command line interface the way you want it, and otherwise, stays out of your way.


const os = require('os')
const cli = require('seeli')

  exitOnError: true
, color: 'green'
, name: 'example'

const Hello = new cli.Command({
  description:"displays a simple hello world command"
, name: 'hello'
, ui: 'dots'
, usage:[
    `${cli.bold("Usage:")} ${cli.get('name')} hello --interactive`
  , `${cli.bold("Usage:")} ${cli.get('name')} hello --name=john`
  , `${cli.bold("Usage:")} ${cli.get('name')} hello --name=john --name=marry --name=paul -v screaming`

, flags:{

      type:[ String, Array ]
    , shorthand:'n'
    , description:"The name of the person to say hello to"
    , required:true

  , 'nested:value' : {
      type: Number
    , shorthand: 'nv'
    , description: 'A newsted Value'
    , name: 'nested'

  , excited: {
    , shorthand: 'e'
    , description:"Say hello in a very excited manner"
    , default:false

  , volume:{
    , choices:['normal', 'screaming']
    , description:"Will yell at each person"
    , default:'normal'
    , shorthand:'v'
, onContent: (content) => {
    // command success
    // content is the final output from run function
    // non string content is not written to stdout automatically
    // you could do it here


, run: async function( cmd, data ){
    const out = [];
    this.ui.start('processing names');
    var names = Array.isArray( data.name ) ? data.name : [ data.name ];
    for( var x = 0; x< names.length; x++ ){
      this.ui.text = (`processing ${names[x]}`)
      await new Promise((resolve) => {
        setTimeout(() => {
          let value = "Hello, " + names[x];
          if( data.excited ){
            value += '!';

          out.push( data.volume === 'screaming' ? value.toUpperCase() : value );
        }, 1000 * x + 1);

    this.ui.succeed('names processed successfully');
    // anything returned from run
    // is emitted from the `content` event
    // strings will automatically be written to stdout
    return out

cli.use('hello', Hello)

now you will have a fully functional hello world command with help and an interactive walk through

node ./cli help world
node ./cli world --help
node ./cli world --interactive
node ./cli world --name=Mark --name=Sally --no-excited

Seeli.run( )

Executes The command line interface


List of all top level registered commands

Seeli.use( name <string>, cmd <Command> )

Registers a new command under the specified name where the name will invoke the associated command

var cli = require('seeli')
var Cmd = new cli.Command();

cli.use('test', Cmd )

Seeli.bold( text <string>)

wraps text in the ansi code for bold

Seeli.green( text <string>)

wraps text in the ansi code for green

Seeli.blue( text <string>)

wraps text in the ansi code for blue

Seeli.red( text <string>)

wraps text in the ansi code for red

Seeli.yellow( text <string>)

wraps text in the ansi code for yellow

Seeli.cyan( text <string>)

wraps text in the ansi code for cyan

Seeli.magenta( text <string>)

wraps text in the ansi code for magenta

Seeli.redBright( text <string>)

wraps text in the ansi code for redBright

Seeli.blueBright( text <string>)

wraps text in the ansi code for blueBright

Seeli.greenBright( text <string>)

wraps text in the ansi code for greenBright

Seeli.yellowBright( text <string>)

wraps text in the ansi code for yellowBright

Seeli.cyanBright( text <string>)

wraps text in the ansi code for cyanBright

Seeli.set( key <string>, value <object> )

sets a conf value.

Seeli.get( key <string> )

A config value to look up. Can be a dot separated key to look up nested values

Supported Confgurations

  • color <String> - The chalk color to use when outputting help text. default green
  • name <String> - the name of the command that is used in generated help
  • exitOnError <Boolean> - Seeli will forcefully exit the current process when an error is encountered. default false
  • exitOnContent <Boolean> - Seeli will forefully exit the current process when it is passed output content from a command. default true
  • help <String> - a file path or module name to a custom help command. This will be passed to require and must export a single command instance
    • seeli.set('help', '/path/to/help/command')

Command( options <object> )


name type default description
description String "" Used to render help output
strict Boolean false When true, commands will error when the receive unknown flags
args Array null if supplied, agrs will be used instead of process.argv
interactive Boolean true If set to false, the flag will be excluded from the interactive prompts
usage String / Array "" A string or array of strings used to generate help text
flags Object {} key value pairs used to control the command where keys are the name of the flag and the values is a configuration object for the flag
ui String dots The kind of progress indicator your command should use
run Function no-op An async function used as the body of the command. It will be passed a subcommand name if one was passed, and a data object containing the processed values from the command input.

Flag Options

name required type description
type true string The type of input that is expected. Boolean types to not expect input. The present of the flag implies true. Additionally, boolean flags allow for --no-<flag> to enforce false. If you want to accept multiple values, you specify type as an array with the first value being the type you which to accept. For example [String, Array ]**** means you will accept multiple string values.
description false string a description of the flag in question.
required false boolean If set to true a RequiredFieldError will be emitted
shorthand false string An options short hand flag that will be expanded out to the long hand flag.
interacive false boolean If set to false the flag will omitted from interactive prompts
default false mixed A value to return if the flag is omitted.
mask false boolean interactive mode only Sets the input type to masked input to hide values
choices false array Used only during an interactive command. Restricts the users options only to the options specified
multi false boolean interactive mode only If choices is specified, and multi is true, this user will be presented a multi checkbox UI allowing them to pick multiple values. The return value will be an array
skip false boolean interactive mode only - if set to true this flag will be omitted from the interactive command prompts
event false boolean if set to true the command will emit an event withe the same name as the flag with the value that was captured for that flag
when false function interactive mode only Receives the current user answers hash and should return true or false depending on whether or not this question should be asked.
validate false function receives user input and should return true if the value is valid, and an error message (String) otherwise. If false is returned, a default error message is provided.
filter false function interactive mode only Receives the user input and return the filtered value to be used inside the program. The value returned will be added to the Answers hash.

Nested Flags

Flag names that contain a colon (:) will be parsed as a nested value in the data that is return to you commands. You can Set arbitrarily deep values. You can use this to automatically construct complex object. Array values are limited to primitive types

// cli --foo:bar:foobar=hello --foo:bar:baz=world --nested:array=1 --nested:array=2

  foo: {
    bar: {
      foobar: "hello"
    , baz: "world"
, nested: {
    array: [1, 2]

Auto Help

Seeli will generate help from the usage string and flags. You can help as a command seeli help <command> or as a flag seeli <command> --help


Your defined run function can be an async function, or a function that returns a Promise. This allows you to do complex async operations and I/O. If an error is thrown, it will be displayed. Otherwise, the content returned from your run function will be output to stdout ( if it returned a String).


Your command's run function has access to an instance of ora allowing you to display progress indicators and helpful messages while you perform other work.


Instances of the seeli Command or Commands the inherit from it as also instances of the EventEmitter class. By default any flag that has its event option set to true will emit an event with the value of of the flag before the run function is executed.

var EventCommand = new cli.Command({
  args:[ '--one', '--no-two']
, flags:{
    , event:true
  , two:{
    , event:true
, run: async function( cmd, data ){
    return data.one && data.two

EventCommand.on('one', function( value ){
  assert.equal( true, value );

EventCommand.on('two', function( value ){
  assert.equal( false, value )

EventCommand.on('content', function( value ){
  assert.equal( false, value );

EventCommand.run( null );