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https://github.com/CleverCloud/cliparse-node

Declarative CLI parsing for node
https://github.com/CleverCloud/cliparse-node

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Declarative CLI parsing for node

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# Declarative CLI parsing for node apps



[![Build Status](https://travis-ci.org/CleverCloud/cliparse-node.svg?branch=master)](https://travis-ci.org/CleverCloud/cliparse-node)

[![Coverage Status](https://coveralls.io/repos/github/CleverCloud/cliparse-node/badge.svg?branch=master)](https://coveralls.io/github/CleverCloud/cliparse-node?branch=master)



This is a library designed to express command-line options. It supports

commands and subcommands (at an arbitrary depth), automatically generates help

text and `usage` contents. You can use custom parsers for attributes and

options values (types supported out of the box: `int`, `bool`, `string`).



Its design is vaguely inspired from

[optparse-applicative](https://hackage.haskell.org/package/optparse-applicative)

which is a great CLI parsing library. JS being not as expressive as Haskell, a

direct port is not possible.



> Disclaimer:

>

> This library has been started by @divarvel as part of his job at Clever Cloud. Since he

> left the company and doesn't use cliparse nor wishes to maintain it anymore, we

> mutually agreed to transfer ownership of the project to CleverCloud.

>

> Big thanks to him for producing this library!



## Enough talk, show me the code



```bash

npm install cliparse

```



```javascript

#!/usr/bin/env node



var cliparse = require("cliparse");

var parsers = cliparse.parsers;



function echoModule(params) {

    

}



function addModule(params) {

    

}



var cliParser = cliparse.cli({

  name: "my-executable",

  description: "Simple CLI written for the sake of the example",

  commands: [



    cliparse.command(

      "echo",

      { description: "Display the given value",

        args: [ cliparse.argument("value", { description: "Simple value" })],

        options: [ cliparse.flag("reverse", { aliases: ["r"], description: "Reverse the value"}) ]

      },

      echoModule),



    cliparse.command(

      "add2",

      { description: "Add 2 to the given integer and display the result",

        args: [

          cliparse.argument("int",

            { default: 0,

              parser: parsers.intParser,

              description: "Int to add 2 to" })

        ]

      },

      addModule)

  ]

});



cliparse.parse(cliParser);

```



Where `echoModule` and `addModule` are callbacks taking a `{ args: ['value'], options: {key: 'value'} }` parameter.



### Generated output



#### Top-level help



```

$ my-executable --help

Usage: my-executable

Simple CLI written for the sake of the example.



Options:

[--help, -?]                    Display help about this program



Available commands:

help                            Display help about this program

echo VALUE                      Display the given value

add2 [INT]                      Add 2 to the given integer and display the result

```



#### Command-level help



```

$ my-executable echo --help

Usage : my-executable echo VALUE

display the given value



Arguments:

VALUE                           Simple value



Options:

[--help, -?]                    Display help about this program

[--reverse, -r]                 Reverse the value

```



## Subcommands



The `command` constructor takes an optional `commands` attribute which allows

you to nest subcommands at an arbitrary level.



```javascript

var testCli = cliparse.cli({

  name: "testCli",

  description: "Simple CLI written for the sake of the example",

  commands: [

    cliparse.command(

      "number",

      { description: "perform simple arithmetic calculations",

        commands: [

          cliparse.command(

            "add",

            { description: "add two integers",

              args: [ intArgument, intArgument]

            }, numberModule.add),

          cliparse.command(

            "multiply",

            { description: "multiply two integers",

              args: [ intArgument, intArgument]

            }, numberModule.multiply)

        ]

      }),

  ]

});

```



## Help command



An help command is automatically generated, with the following syntax:



```bash

$ my-executable help   <...>

```



It can be disabled by setting `helpCommand` to `false` in `cliparse.cli` options.



## Autocompletion



CLI parse allows you to generate autocompletion scripts for bash and zsh (work

in progress). Generate the script in your npm post-install hook and add it to

your users shell completion scripts to enable it.



It supports completion on commands, options and arguments, as well as on the

help command. Completion on options and arguments are configurable: you can

declare your own completion methods.



All the completion logic is handled within your app, so it will work with

dynamically defined commands.



### Bash



Generate the completion script and put it in bash completion dir:



```bash

$ my-executable --bash-autocomplete-script /complete/path/to/my-executable > ~/.bash_completion.d/my-executable

```



Normally `.bash_completion.d` is automatically sourced. You can put the file

where you want and source it manually.



### ZSH



Generate the completion script and put it in zsh completion dir:



```bash

$ my-executable --zsh-autocomplete-script /complete/path/to/my-executable > ~/.zsh.d/completion/_my-executable

```



The file name **must** be `_my-executable` (if your executable is named

`my-executable`). You can put the file where you want as long as it's in a

directory listed in `$fpath`.



### Custom completion



You can have custom completion for option or arguments, by passing a custom

complete function (see [API](#option)).



For instance to complete on a list of colors:



```javascript

var colorCompleter = function() {

  return autocomplete.words(['mauve', 'blue', 'yellow', 'purple', 'parabolic']);

};

```



To complete on a list of files:



```javascript

var fileCompleter = function() {

  return autocomplete.files;

};

```



The `complete` function can also return a promise for async results.



## API



### `cli`



```javascript

cli(opts, cb);

```



Where opts can contain



 - `name`: the name of the executable (if not provided, `process.argv` is used)

 - `description`: a one-line description of the executable

 - `version`: the version number of the executable (displayed by `--version`.

   Default value: `null`

 - `options`: array of top-level options (constructed with `option` or `flag`). Default

   value: `[]`.

 - `commands`: array of commands (constructed with `command`). Default value: `[]`

 - `args`: array of arguments (constructed with `argument`). If your app

   doesn't have commands.

 - `helpCommand`: Generate a `help` command. Default value: `true`.



If your application is not solely made of commands, you can pass an action

callback. If you don't give a callback, calling your application without any

argument will display a `usage` message describing the available commands.



### `option`



```javascript

option(name, opts);

```



Where name is the name of the flag, and opts can contain



 - `aliases`: array of other names (the shorthand name for instance. Default

   value: `[]`

 - `metavar`: the name of the value of the option (if applicable: for flags,

  see below)

 - `parser`: the parser used to parse the value. Default value: `stringParser`

   which is a noop parser returning the string.

 - `description`: a single-line description of what the option is about. Default

   value: the empty string.

 - `required`: make option mandatory

 - `default`: value used if the option is not given any value. If set,

   overrides the `required` setting.

 - `complete`: a function returning completion results for the option (or a

   promise of results). Default value: a function returning an empty result.

 - `expects_value`: does the option expect a value? Default: true. Rather than

   setting it yourself, use `flag`.



### `flag`



Shorthand for flags (ie options with boolean values, defaulting to `false`,

doesn't expect a value)



```javascript

flag(name, opts);

```



Acts like `option`, with different defaults:



 - `parser` defaults to `booleanParser`, which parses boolean values

 - `default` defaults to `false`



### `argument`



```javascript

argument(name, opts);

```



Where opts can contain



 - `parser`: ther parser used to parse the value of the argument. Default

   value: `stringParser`

 - `description`: a single-line description of what the argument is about.

 - `default`: value used if the argument is not given any value

 - `complete`: a function returning completion results for the argument. Default

   value: a function returning an empty result.



### `command`



```javascript

command(name, opts, cb);

```



Where `name` is the name of the command , and `opts` can contain



 - `description`: a single line description of the command

 - `args`: array of arguments (constructed with `argument`). Default value: `[]`

 - `options`: array of options (constructed with `option`). Default value:

   `[]`

- `privateOptions`: array of options that will not be inherited in sub commands. Default value:

   `[]`

 - `commands`: array of subcommands (constructed with `command`). Default

   value: `[]`



`cb` is a callback which is called when the command match (if no subcommand

match). It is called with a `{ args: ['value'], options: {key: 'value'}}` object. `opts` contains

both the options of the command and the options of the parent commands.



### Parsers



Basic scalar types (`int`, `bool`, and `string`) are already supported. It is

possible to declare your own parsers to validate more specific types of values

(eg. enums).



A parser is a function `String -> Result` where `Result` is either 



 - `{ success:  }`

 - or `{ error:  }`



Parser results can be constructed with `parsers.success()` and

`parsers.error()`.



For instance, to parse an hexadecimal RBG color:



```javascript

var colorParser = function(input) {

  var pattern = /^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i;

  var matches = input.match(pattern);

  if(matches !== null) {

    var components = matches.slice(1,4)

          .map(function(x) { return parseInt(x, 16); });

    return parsers.success(components);

  } else {

    return parsers.error("invalid color code");

  }

}

```



### Autocompletion helpers



#### Autocompletion results



`autocomplete.empty`: no results



`autocomplete.words([…])`: list of words



`autocomplete.glob()`: files matching glob (eg. `*.log`).



`autocomplete.files`: files



`autocomplete.directories`: directories



You can combine autocompletion results:



`autocomplete.mappend()`: combine results from `result1` and

`result2`. As globs can't be combined, the last one wins (if set).



`autocomplete.mconcat([  ])`: reduce a list of result to a composite

result with `mappend`. If the list is empty, then `empty` is returned.



## Contributing



Make sure you don't break anything.



```bash

npm test

```



## ToDo



### For `0.3.0`



 - [x] Declare flags as boolean options in minimist

 - [ ] [Variadic arguments](https://github.com/divarvel/cliparse-node/issues/7)

 - [ ] [Parse failure on unrecognized options / arguments](https://github.com/divarvel/cliparse-node/issues/1)

 - [ ] [Cleaner display of errors](https://github.com/divarvel/cliparse-node/issues/8)



### Later



 - [ ] [Dedicated ZSH completion (help welcome :-\])](https://github.com/divarvel/cliparse-node/issues/9)