exec-promise

exec-promise

Testable CLIs with promises

Features

• executes the passed function with command line arguments
• wait for completion (sync or promise) before stopping Node
• in case of exception: pretty print the value and exit with exit code 1
• in case of returned value (not undefined):
  • if valid exit code (integer), exit Node with it
  • otherwise, pretty print it

Introduction

TODO

• executables should be testable
• the execution flow should be predictable and followable (promises)

Install

Download manually or with package-manager.

npm

npm install --save exec-promise

This library requires promises support, for Node versions prior to 0.12 see this page to enable them.

Example

ES 2015

import execPromise from 'exec-promise'

// - The command line arguments are passed as first parameter.
// - Node will exists as soon as the promise is settled (with a code
//   different than 0 in case of an error).
// - All errors are catched and properly displayed with a stack
//   trace.
// - Any returned value (i.e. not undefined) will be prettily
//   displayed
execPromise(async args => {
  // ... do what you want here!
})

ES5

module.exports = function (args) {
  if (args.indexOf('-h') !== -1) {
    return 'Usage: my-program [-h | -v]'
  }

  if (args.indexOf('-v') !== -1) {
    var pkg = require('./package')
    return 'MyProgram version ' + pkg.version
  }

  var server = require('http').createServer()
  server.listen(80)

  // The program will run until the server closes or encounters an
  // error.
  return require('event-to-promise')(server, 'close')
}

// Executes the exported function if this module has been called
// directly.
if (!module.parent) {
  require('exec-promise')(module.exports)
}

Contributing

Contributions are very welcome, either on the documentation or on the code.

You may:

• report any issue you've encountered;
• fork and create a pull request.

License

ISC © Julien Fontanet