74 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			74 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|  | # universalify
 | ||
|  | 
 | ||
|  | [](https://travis-ci.org/RyanZim/universalify) | ||
|  | 
 | ||
|  | Make a callback- or promise-based function support both promises and callbacks. | ||
|  | 
 | ||
|  | Uses the native promise implementation. | ||
|  | 
 | ||
|  | ## Installation
 | ||
|  | 
 | ||
|  | ```bash | ||
|  | npm install universalify | ||
|  | ``` | ||
|  | 
 | ||
|  | ## API
 | ||
|  | 
 | ||
|  | ### `universalify.fromCallback(fn)`
 | ||
|  | 
 | ||
|  | Takes a callback-based function to universalify, and returns the universalified  function. | ||
|  | 
 | ||
|  | Function must take a callback as the last parameter that will be called with the signature `(error, result)`. `universalify` does not support calling the callback with more than three arguments, and does not ensure that the callback is only called once. | ||
|  | 
 | ||
|  | ```js | ||
|  | function callbackFn (n, cb) { | ||
|  |   setTimeout(() => cb(null, n), 15) | ||
|  | } | ||
|  | 
 | ||
|  | const fn = universalify.fromCallback(callbackFn) | ||
|  | 
 | ||
|  | // Works with Promises: | ||
|  | fn('Hello World!') | ||
|  | .then(result => console.log(result)) // -> Hello World! | ||
|  | .catch(error => console.error(error)) | ||
|  | 
 | ||
|  | // Works with Callbacks: | ||
|  | fn('Hi!', (error, result) => { | ||
|  |   if (error) return console.error(error) | ||
|  |   console.log(result) | ||
|  |   // -> Hi! | ||
|  | }) | ||
|  | ``` | ||
|  | 
 | ||
|  | ### `universalify.fromPromise(fn)`
 | ||
|  | 
 | ||
|  | Takes a promise-based function to universalify, and returns the universalified  function. | ||
|  | 
 | ||
|  | Function must return a valid JS promise. `universalify` does not ensure that a valid promise is returned. | ||
|  | 
 | ||
|  | ```js | ||
|  | function promiseFn (n) { | ||
|  |   return new Promise(resolve => { | ||
|  |     setTimeout(() => resolve(n), 15) | ||
|  |   }) | ||
|  | } | ||
|  | 
 | ||
|  | const fn = universalify.fromPromise(promiseFn) | ||
|  | 
 | ||
|  | // Works with Promises: | ||
|  | fn('Hello World!') | ||
|  | .then(result => console.log(result)) // -> Hello World! | ||
|  | .catch(error => console.error(error)) | ||
|  | 
 | ||
|  | // Works with Callbacks: | ||
|  | fn('Hi!', (error, result) => { | ||
|  |   if (error) return console.error(error) | ||
|  |   console.log(result) | ||
|  |   // -> Hi! | ||
|  | }) | ||
|  | ``` | ||
|  | 
 | ||
|  | ## License
 | ||
|  | 
 | ||
|  | MIT |