sade
Smooth (CLI) Operator 🎶
Sade is a small but powerful tool for building command-line interface (CLI) applications for Node.js that are fast, responsive, and helpful!
It enables default commands, git-like subcommands, option flags with aliases, default option values with type-casting, required-vs-optional argument handling, command validation, and automated help text generation!
Your app's UX will be as smooth as butter... just like Sade's voice. 😉
Install
$ npm install --save sade
Usage
Input:
#!/usr/bin/env node
const sade = require('sade');
const prog = sade('my-cli');
prog
.version('1.0.5')
.option('--global, -g', 'An example global flag')
.option('-c, --config', 'Provide path to custom config', 'foo.config.js');
prog
.command('build <src> <dest>')
.describe('Build the source directory. Expects an `index.js` entry file.')
.option('-o, --output', 'Change the name of the output file', 'bundle.js')
.example('build src build --global --config my-conf.js')
.example('build app public -o main.js')
.action((src, dest, opts) => {
console.log(`> building from ${src} to ${dest}`);
console.log('> these are extra opts', opts);
});
prog.parse(process.argv);
Output:
$ my-cli --help
Usage
$ my-cli <command> [options]
Available Commands
build Build the source directory.
For more info, run any command with the `--help` flag
$ my-cli build --help
Options
-v, --version Displays current version
-g, --global An example global flag
-c, --config Provide path to custom config (default foo.config.js)
-h, --help Displays this message
$ my-cli build --help
Description
Build the source directory.
Expects an `index.js` entry file.
Usage
$ my-cli build <src> [options]
Options
-o, --output Change the name of the output file (default bundle.js)
-g, --global An example global flag
-c, --config Provide path to custom config (default foo.config.js)
-h, --help Displays this message
Examples
$ my-cli build src build --global --config my-conf.js
$ my-cli build app public -o main.js
Tips
-
Define your global/program-wide version, options, description, and/or examples first.
Once you define a Command, you can't access the global-scope again.
-
Define all commands & options in the order that you want them to appear.
Sade will not mutate or sort your CLI for you. Global options print before local options.
-
Required arguments without values will error & exit
An Insufficient arguments!
error will be displayed along with a help prompt.
-
Don't worry about manually displaying help~!
Your help text is displayed automatically... including command-specific help text!
-
Automatic default/basic patterns
Usage text will always append [options]
& --help
and --version
are done for you.
-
Only define what you want to display!
Help text sections (example, options, etc) will only display if you provide values.
Subcommands
Subcommands are defined & parsed like any other command! When defining their usage
, everything up until the first argument ([foo]
or <foo>
) is interpreted as the command string.
They should be defined in the order that you want them to appear in your general --help
output.
Lastly, it is not necessary to define the subcommand's "base" as an additional command. However, if you choose to do so, it's recommended that you define it first for better visibility.
const prog = sade('git');
prog
.command('remote')
.describe('Manage set of tracked repositories')
.action(opts => {
console.log('~> Print current remotes...');
});
prog
.command('remote add <name> <url>', 'Demo...')
.action((name, url, opts) => {
console.log(`~> Adding a new remote (${name}) to ${url}`);
});
prog
.command('remote rename <old> <new>', 'Demo...')
.action((old, nxt, opts) => {
console.log(`~> Renaming from ${old} to ${nxt}~!`);
});
Single Command Mode
In certain circumstances, you may only need sade
for a single-command CLI application.
Note: Until v1.6.0
, this made for an awkward pairing.
To enable this, you may make use of the isSingle
argument. Doing so allows you to pass the program's entire usage
text into the name
argument.
With "Single Command Mode" enabled, your entire binary operates as one command. This means that any prog.command
calls are disallowed & will instead throw an Error. Of course, you may still define a program version, a description, an example or two, and declare options. You are customizing the program's attributes as a whole.*
* This is true for multi-command applications, too, up until your first prog.command()
call!
Example
Let's reconstruct sirv-cli
, which is a single-command application that (optionally) accepts a directory from which to serve files. It also offers a slew of option flags:
sade('sirv [dir]', true)
.version('1.0.0')
.describe('Run a static file server')
.example('public -qeim 31536000')
.example('--port 8080 --etag')
.example('my-app --dev')
.option('-D, --dev', 'Enable "dev" mode')
.option('-e, --etag', 'Enable "Etag" header')
.option('-H, --host', 'Hostname to bind', 'localhost')
.option('-p, --port', 'Port to bind', 5000)
.action((dir, opts) => {
})
.parse(process.argv);
When sirv --help
is run, the generated help text is trimmed, fully aware that there's only one command in this program:
Description
Run a static file server
Usage
$ sirv [dir] [options]
Options
-D, --dev Enable "dev" mode
-e, --etag Enable "Etag" header
-H, --host Hostname to bind (default localhost)
-p, --port Port to bind (default 5000)
-v, --version Displays current version
-h, --help Displays this message
Examples
$ sirv public -qeim 31536000
$ sirv --port 8080 --etag
$ sirv my-app --dev
Command Aliases
Command aliases are alternative names (aliases) for a command. They are often used as shortcuts or as typo relief!
The aliased names do not appear in the general help text.
Instead, they only appear within the Command-specific help text under an "Aliases" section.
Limitations
- You cannot assign aliases while in Single Command Mode
- You cannot call
prog.alias()
before defining any Commands (via prog.commmand()
) - You, the developer, must keep track of which aliases have already been used and/or exist as Command names
Example
Let's reconstruct the npm install
command as a Sade program:
sade('npm')
.command('install [package]', 'Install a package', {
alias: ['i', 'add', 'isntall']
})
.option('-P, --save-prod', 'Package will appear in your dependencies.')
.option('-D, --save-dev', 'Package will appear in your devDependencies.')
.option('-O, --save-optional', 'Package will appear in your optionalDependencies')
.option('-E, --save-exact', 'Save exact versions instead of using a semver range operator')
When we run npm --help
we'll see this general help text:
Usage
$ npm <command> [options]
Available Commands
install Install a package
For more info, run any command with the `--help` flag
$ npm install --help
Options
-v, --version Displays current version
-h, --help Displays this message
When we run npm install --help
— or the help flag with any of install
's aliases — we'll see this command-specific help text:
Description
Install a package
Usage
$ npm install [package] [options]
Aliases
$ npm i
$ npm add
$ npm isntall
Options
-P, --save-prod Package will appear in your dependencies.
-D, --save-dev Package will appear in your devDependencies.
-O, --save-optional Package will appear in your optionalDependencies
-E, --save-exact Save exact versions instead of using a semver range operator
-h, --help Displays this message
API
sade(name, isSingle)
Returns: Program
Returns your chainable Sade instance, aka your Program
.
name
Type: String
Required: true
The name of your Program
/ binary application.
isSingle
Type: Boolean
Default: name.includes(' ');
If your Program
is meant to have only one command.
When true
, this simplifies your generated --help
output such that:
- the "root-level help" is your only help text
- the "root-level help" does not display an
Available Commands
section - the "root-level help" does not inject
$ name <command>
into the Usage
section - the "root-level help" does not display
For more info, run any command with the
--help flag
text
You may customize the Usage
of your command by modifying the name
argument directly.
Please read Single Command Mode for an example and more information.
Important: Whenever name
includes a custom usage, then isSingle
is automatically assumed and enforced!
prog.command(usage, desc, opts)
Create a new Command for your Program. This changes the current state of your Program.
All configuration methods (prog.describe
, prog.action
, etc) will apply to this Command until another Command has been created!
usage
Type: String
The usage pattern for your current Command. This will be included in the general or command-specific --help
output.
Required arguments are wrapped with <
and >
characters; for example, <foo>
and <bar>
.
Optional arguments are wrapped with [
and ]
characters; for example, [foo]
and [bar]
.
All arguments are positionally important, which means they are passed to your current Command's handler
function in the order that they were defined.
When optional arguments are defined but don't receive a value, their positionally-equivalent function parameter will be undefined
.
Important: You must define & expect required arguments before optional arguments!
sade('foo')
.command('greet <adjective> <noun>')
.action((adjective, noun, opts) => {
console.log(`Hello, ${adjective} ${noun}!`);
})
.command('drive <vehicle> [color] [speed]')
.action((vehicle, color, speed, opts) => {
let arr = ['Driving my'];
arr.push(color ? `${color} ${vehicle}` : vehicle);
speed && arr.push(`at ${speed}`);
opts.yolo && arr.push('...YOLO!!');
let str = arr.join(' ');
console.log(str);
});
$ foo greet beautiful person
$ foo drive car
$ foo drive car red
$ foo drive car blue 100mph --yolo
desc
Type: String
Default: ''
The Command's description. The value is passed directly to prog.describe
.
opts
Type: Object
Default: {}
opts.alias
Type: String|Array
Optionally define one or more aliases for the current Command.
When declared, the opts.alias
value is passed directly to the prog.alias
method.
const A = sade('bin')
.command('build', 'My build command', { alias: 'b' })
.command('watch', 'My watch command', { alias: ['w', 'dev'] });
const B = sade('bin')
.command('build', 'My build command').alias('b')
.command('watch', 'My watch command').alias('w', 'dev');
opts.default
Type: Boolean
Manually set/force the current Command to be the Program's default command. This ensures that the current Command will run if no command was specified.
Important: If you run your Program without a Command and without specifying a default command, your Program will exit with a No command specified
error.
const prog = sade('greet');
prog.command('hello');
prog.command('howdy', '', { default:true });
prog.describe(text)
Add a description to the current Command.
text
Type: String|Array
The description text for the current Command. This will be included in the general or command-specific --help
output.
Internally, your description will be separated into an Array
of sentences.
For general --help
output, only the first sentence will be displayed. However, all sentences will be printed for command-specific --help
text.
Note: Pass an Array
if you don't want internal assumptions. However, the first item is always displayed in general help, so it's recommended to keep it short.
prog.alias(...names)
Define one or more aliases for the current Command.
Important: An error will be thrown if:
1) the program is in Single Command Mode; or
2) prog.alias
is called before any prog.command
.
names
Type: String
The list of alternative names (aliases) for the current Command.
For example, you may want to define shortcuts and/or common typos for the Command's full name.
Important: Sade does not check if the incoming names
are already in use by other Commands or their aliases.
During conflicts, the Command with the same name
is given priority, otherwise the first Command (according to Program order) with name
as an alias is chosen.
The prog.alias()
is append-only, so calling it multiple times within a Command context will keep all aliases, including those initially passed via opts.alias
.
sade('bin')
.command('hello <name>', 'Greet someone by their name', {
alias: ['hey', 'yo']
})
.alias('hi', 'howdy')
.alias('hola', 'oi');
prog.action(handler)
Attach a callback to the current Command.
handler
Type: Function
The function to run when the current Command is executed.
Its parameters are based (positionally) on your Command's usage
definition.
All options, flags, and extra/unknown values are included as the last parameter.
Note: Optional arguments are also passed as parameters & may be undefined
!
sade('foo')
.command('cp <src> <dest>')
.option('-f, --force', 'Overwrite without confirmation')
.option('-c, --clone-dir', 'Copy files to additional directory')
.option('-v, --verbose', 'Enable verbose output')
.action((src, dest, opts) => {
console.log(`Copying files from ${src} --> ${dest}`);
opts.c && console.log(`ALSO copying files from ${src} --> ${opts['clone-dir']}`);
console.log('My options:', opts);
})
prog.example(str)
Add an example for the current Command.
str
Type: String
The example string to add. This will be included in the general or command-specific --help
output.
Note: Your example's str
will be prefixed with your Program's name
.
prog.option(flags, desc, value)
Add an Option to the current Command.
flags
Type: String
The Option's flags, which may optionally include an alias.
You may use a comma (,
) or a space (
) to separate the flags.
Note: The short & long flags can be declared in any order. However, the alias will always be displayed first.
Important: If using hyphenated flag names, they will be accessible as declared within your action()
handler!
prog.option('--global');
prog.option('-g, --global');
prog.option('--global -g');
desc
Type: String
The description for the Option.
value
Type: String
The default value for the Option.
Flags and aliases, if parsed, are true
by default. See mri
for more info.
Note: You probably only want to define a default value
if you're expecting a String
or Number
value type.
If you do pass a String
or Number
value type, your flag value will be casted to the same type. See mri#options.default
for info~!
prog.version(str)
The --version
and -v
flags will automatically output the Program version.
str
Type: String
Default: 0.0.0
The new version number for your Program.
Note: Your Program version
is 0.0.0
until you change it.
prog.parse(arr, opts)
Parse a set of CLI arguments.
arr
Type: Array
Your Program's process.argv
input.
Important: Do not .slice(2)
! Doing so will break parsing~!
opts
Type: Object
Default: {}
Additional process.argv
parsing config. See mri
's options for details.
Important: These values override any internal values!
prog
.command('hello')
.option('-f, --force', 'My flag');
prog.parse(process.argv, {
alias: {
f: ['foo', 'fizz']
},
default: {
abc: 123
}
});
opts.unknown
Type: Function
Default: undefined
Callback to run when an unspecified option flag has been found. This is passed directly to mri
.
Your handler will receive the unknown flag (string) as its only argument.
You may return a string, which will be used as a custom error message. Otherwise, a default message is displayed.
sade('sirv')
.command('start [dir]')
.parse(process.argv, {
unknown: arg => `Custom error message: ${arg}`
});
opts.lazy
Type: Boolean
Default: false
If true, Sade will not immediately execute the action
handler. Instead, parse()
will return an object of { name, args, handler }
shape, wherein the name
is the command name, args
is all arguments that would be passed to the action handler, and handler
is the function itself.
From this, you may choose when to run the handler
function. You also have the option to further modify the args
for any reason, if needed.
let { name, args, handler } = prog.parse(process.argv, { lazy:true });
console.log('> Received command: ', name);
handler.apply(null, args);
prog.help(cmd)
Manually display the help text for a given command. If no command name is provided, the general/global help is printed.
Your general and command-specific help text is automatically attached to the --help
and -h
flags.
Note: You don't have to call this directly! It's automatically run when you bin --help
cmd
Type: String
Default: null
The name of the command for which to display help. Otherwise displays the general help.
License
MIT © Luke Edwards