Rawcmd Framework

 

Rawcmd allows for building command-line user interfaces in NodeJS. It's a lightweight and open-source framework, written with TypeScript. It's actively maintained, well tested and already used in production environments. The source code is available on GitHub where you can also find our issue tracker.

Introduction

Rawcmd represents a scaffold for creating reach command-line user interfaces in NodeJS. The purpose of this framework is to provide the logic and methods for building custom command-line utilities.

Installation

Run the command below to install the package.

$ npm install --save @rawcmd/core
$ npm install --save @rawcmd/typewriters // OPTIONAL

This package uses promises thus you need to use Promise polyfill when promises are not supported.

Usage

Below we explain some of the most important features that this framework provides. Please check the API section to see a complete list of features.

Defining commands

Command represents the entry point of your command-line program.

import { Command } from '@rawcmd/core';

const command = new Command({
  resolver() {
    console.log('Hello World!');
  },
});

command.perform(); // prints "Hello World!"

By nesting commands we can create a tree of commands.

const command = new Command({ // entry point (root)
  commands: [
    new Command({ // first level
      name: 'list',
      resolver() {
        console.log('List all!');
      },
      commands: [
        new Command({ // second level
          name: 'latest',
          resolver() {
            console.log('List latest!');
          },
        }),
      ],
    }),
  ],
});

command.perform('list'); // prints "List all!"
command.perform('list', 'latest'); // prints "List latest!"

Processing options

Every command accepts options which we can use to adjust command execution. We can apply parsers and validators to each option to make sure the resolver receives expected input data. In case one of validators fail, the resolver throws ValidationError class instance.

const command = new Command({
  options: [
    {
      name: 'name',
      alias: 'n',
      parse: { // check @rawmodel/parsers for predefined parsers
        resolver(v) { return `${v}` }, // transform value to string
      },
      validate: [ // check @rawmodel/validators for predefined validators
        {
          code: 4220001,
          resolver() { return false; }, // return `false` so validation fails
        },
      ],
    },
  ],
  resolver(input) {
    console.log(input); // => { "options": { "name": "John" }, "tail": "arg1 arg2" }
  },
});

command.perform('--name=John', '--', 'arg1', 'arg2').catch((error) => {
  console.log(error); // => { "code": 4220001, "name": "ValidationError", "message": "Validation failed." }
});

The validation is handled by the powerful RawModel framework where you will find more details regarding data validation.

Printing messages

Every command provides methods for printing messages to the output stream. By default the output stream is set to process.stdout.

const command = new Command({
  resolver() {
    this.print('Hello World!'); // prints message with EOL
  },
});

Messages can be formated through different typewriters which can be found in @rawcmd/typewriters package.

import { textTypewriter } from '@rawcmd/typewriters'; 

const typewriteGreen = textTypewriter({
  bold: true,
  color: TextColor.GREEN,
});

const command = new Command({
  resolver() {
    this.write( // prints "100%" as strong green text
      typewriteGreen('100'),
      typewriteGreen('%'),
    );
    this.break(); // prints EOL
  },
});

Handling errors

Errors should be triggered directly within resolver and handled outside command class.

import { RuntimeError } from '@rawcmd/core';

const command = new Command({
  resolver() {
    throw new RuntimeError(500001);
  },
});

command.perform().catch((error) => {
  command.print('Error', error.message);
});

Beside the ValidationError which we already mentioned above, RuntimeError can be thrown when an error accures. It's advised that you use your custom errors which extend GenericError class.

Creating executable file

TODO

API

NOTE: This section covers only the end-user related classes and methods. Please read the source code to explore more details.

@rawcmd/core

Command(recipe, config)

Command class for defining executable command.

Option	Type	Required	Default	Description
recipe.name	String	No	-	Command name.
recipe.description	String	No	-	Command description.
recipe.options.$.name	String	Yes	-	Option name.
recipe.options.$.alias	String	No	-	Option alias.
recipe.options.$.description	String	No	-	Option description.
recipe.options.$.setter	Function	No	-	Custom option setter. Check Rawmodel for details.
recipe.options.$.getter	Function	No	-	Custom option getter. Check Rawmodel for details.
recipe.options.$.parser	Object	No	-	Option parser configuration. Check Rawmodel for details.
recipe.options.$.defaultValue	String, Function	No	-	Option default value. Check Rawmodel for details.
recipe.options.$.emptyValue	String, Function	No	-	Option empty value. Check Rawmodel for details.
recipe.options.$.validators	ValidatorRecipe[]	No	-	List of option validators. Check Rawmodel for details.
recipe.options.$.handlers	HandlerRecipe[]	No	-	List of option error handlers. Check Rawmodel for details.
recipe.commands	Command[]	No	-	List of sub commands.
recipe.resolver	Function	No	-	Command resolver.
config.parent	Command	No	-	Parent command class instance.
config.context	Context	No	-	Arbitrary context data.
config.typewriter	Typewriter	No	-	Typewriter class instance.

Command.prototype.name: String

Returns command name.

Command.prototype.description: String

Returns command description.

Command.prototype.getAncestors(): Command[]

Returns a list of all parent command instances.

Command.prototype.getContext(): Context

Returns custom context defined at initialization time.

Command.prototype.getParent(): Command

Returns parent command instance.

Command.prototype.getTypewriter(): Typewriter

Returns typewriter class instance.

Command.prototype.perform(...args): Promise

Performs a command based on the provided command-line arguments.

Option	Type	Required	Default	Description
args	String[]	No	-	List of command-line arguments (e.g. ['init', '--name=foo']). Expects parameters as process.argv.slice(2).

Command.prototype.write(...messages): Command

Appends outptu stream with messages.

Option	Type	Required	Default	Description
messages	string[]	Yes	-	List of arbirary messages.

Command.prototype.print(...messages): Command

Writes messages to outptu stream with EOL at the end.

Option	Type	Required	Default	Description
messages	string[]	Yes	-	List of arbirary messages.

Command.prototype.break(): Command

Writes EOL to outptu stream.

Command.prototype.spin(message): Command

Writes a message to outptu stream as spinner animation.

Option	Type	Required	Default	Description
message	string	Yes	-	Arbirary message.

EOL: String

Holds a new-line character.

@rawcmd/typewriters

commandsTypewriter(options): Function(command)

Returns a function which builds a string showing a list of all available sub commands with descriptions.

Option	Type	Required	Default	Description
options.title	String	No	-	Section title (defaults to Commands).
options.paddingWidth	Integer	No	-	Dotted padding size (defaults to 5).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

contentsTypewriter(options): Function(data)

Returns a function which builds an arbitrary table of contents string with names and decriptions

Option	Type	Required	Default	Description
options.paddingWidth	Integer	No	-	Dotted padding size (defaults to 5).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
data	String[][]	Yes	-	List of arrays with names and descriptions.

helpTypewriter(options): Function(data)

Returns a function which builds a string describing command abilities and other useful information.

Option	Type	Required	Default	Description
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

linksTypewriter(options): Function(command)

Returns a function which builds a string representing a list of all usefull support references and links.

Option	Type	Required	Default	Description
options.title	String	No	-	Section title (defaults to Links).
options.paddingWidth	Integer	No	-	Dotted padding size (defaults to 5).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

optionsTypewriter(options): Function(command)

Returns a function which builds a string representing a list of all available command options with descriptions.

Option	Type	Required	Default	Description
options.title	String	No	-	Section title (defaults to Options).
options.paddingWidth	Integer	No	-	Dotted padding size (defaults to 5).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

rowTypewriter(columns, options): Function(data)

Converts data to stringified table.

Option	Type	Required	Default	Description
columns.$.index	Integer	Yes	-	Column index.
columns.$.width	Integer	No	-	Columns width.
columns.$.textAlign	String	No	left	Text alignment.
columns.$.textLength	Integer	No	-	Text truncation size.
columns.$.textWrap	Boolean	No	true	Wrapps long strings into multiple rows.
columns.$.truncate	Integer	No	-	Truncate text at position.
options.separatorSymbol	String	No	-	Custom string between columns.
options.truncationSymbol	String	No	-	Custom truncation simbol.
data	Any[][]	Yes	-	Two dimensional table of arbitrary data. Values are automatically converted to string.

import { rowTypewriter } from '@rawcmd/typewriters';

const typewriter = rowTypewriter([
  { index: 0, width: 20 },
  { index: 1, width: 60 },
], {
  separatorSymbol: ' | ',
});
const text = typewriter([
  'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
  'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
]);

summaryTypewriter(options): Function(command)

Returns a function which builds a string representing command summary text.

Option	Type	Required	Default	Description
options.title	String	No	-	Section title (defaults to Summary).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

textTypewriter(options): Function(data)

Applyes styles to the provided string.

Option	Type	Required	Default	Description
options.reset	Boolean	No	-	Resets current styles.
options.bold	Boolean	No	-	Makes text brighter.
options.dim	Boolean	No	-	Makes text darker.
options.underline	Boolean	No	-	Makes text underlined.
options.inverse	Boolean	No	-	Inverses font and background colors.
options.color	String	No	-	Applyes a color to text.
options.background	Boolean	No	-	Applyes a color to background.
data	String	Yes	-	Arbitrary string.

import { TextAlign, TextColor, textTypewriter } from '@rawcmd/typewriters';

const typewriter = textTypewriter({
  align: TextAlign.RIGHT,
  bold: true,
  color: TextColor.MAGENTA
});
const text = typewriter('Hello World!');

titleTypewriter: Function(text)

Returns a function which builds a string representing section title.

Option	Type	Required	Default	Description
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
text	String	Yes	-	Arbitrary text.

usageTypewriter: Function(command)

Returns a function which builds a string showing how the command should be used with examples.

Option	Type	Required	Default	Description
options.title	String	No	-	Section title (defaults to Usage).
options.totalWidth	Integer	No	-	Allowed horizontal width (defaults to 80).
command	Command	Yes	-	Command class instance.

Packages

Package	Description	Version
@rawcmd/core	Core framework logic.
@rawcmd/text	Text manipulation methods.
@rawcmd/typewriters	Collection of typewriters.
@rawcmd/utils	Helper functions.

Contributing

See CONTRIBUTING.md for how to help out.

Licence

See LICENSE for details.