callback-and-promise

callback-and-promise

make generic async function return promise when callback not present.

• Supports both callback and promise
• Preserves function names
• Uses a native promise implementation if available and tries to fall back to bluebird
• Converts multiple arguments from the callback into an Array

Installation

$ npm install callback-and-promise --save

Usage

Examples

• Promisifies a single function:

var promisify = require('callback-and-promise');
 
var somethingAsync = promisify(function somethingAsync(a, b, c, callback) {
  callback(null, a, b, c);
});
 
// return a promise when callback not present
somethingAsync(a, b, c).then().catch();
 
// common async style
somethingAsync(a, b, c, callback);

• Promisifies all the selected functions in an object:

var promisifyAll = require('callback-and-promise/all');
 
var fs = promisifyAll(require('fs'), {}, [
  'readFile',
  'writeFile',
]);
 
fs.readFile(__filename).then(function (buffer) {
  console.log(buffer.toString());
});

APIs

var fn = promisify([name], fn)

• name - custom function name
• fn - the source function

var obj = promisifyAll(source, [obj], [methods])

• source - the source object for the async functions
• obj - the destination to set all the promisified methods
• methods - an array of method names of source

License

MIT