Acme.BookStore.HttpApi.Host/node_modules/async-done/README.md

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# async-done

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Allows libraries to handle various caller provided asynchronous functions uniformly. Maps promises, observables, child processes and streams, and callbacks to callback style.

As async conventions evolve, it is useful to be able to deal with several different *styles* of async completion uniformly. With this module you can handle completion using a node-style callback, regardless of a return value that's a promise, observable, child process or stream.

## Usage

### Successful completion

```js
var asyncDone = require('async-done');

asyncDone(function(done){
  // do async things
  done(null, 2);
}, function(error, result){
  // `error` will be null on successful execution of the first function.
  // `result` will be the result from the first function.
});
```

### Failed completion

```js
var asyncDone = require('async-done');

asyncDone(function(done){
  // do async things
  done(new Error('Some Error Occurred'));
}, function(error, result){
  // `error` will be an error from the first function.
  // `result` will be undefined on failed execution of the first function.
});
```

## API

### `asyncDone(fn, callback)`

Takes a function to execute (`fn`) and a function to call on completion (`callback`).

#### `fn([done])`

Optionally takes a callback to call when async tasks are complete.

#### Completion and Error Resolution

* `Callback` (`done`) called
  - Completion: called with null error
  - Error: called with non-null error
* `Stream` or `EventEmitter` returned