aah

A JavaScript library of async/await helpers

aah : object

Kind: global namespace

• aah : object
  • .Callbackify ⇒ function
  • .CatchError ⇒ function
  • .Delay ⇒ function
  • .InOrder ⇒ function
  • .InParallel ⇒ function
  • .InSeries ⇒ function
  • .ParallelFilter ⇒ function
  • .ParallelMap ⇒ function
  • .PassThrough
  • .Promisify ⇒ function
  • .Race ⇒ function
  • .TimeIn ⇒ function
  • .TimeOut ⇒ function
  • .Assert(validator, message) ⇒ taskFunction
  • .Logging(...statements) ⇒ function

aah.Callbackify ⇒ function

	const task = Callbackify(
		async (i) => i + 1
	);

	// logs 'res 1', eventually
	task(
		(err, res) => console.log('res', res),
		0
	);

Kind: static property of aah
Returns: function - a callback-expecting function
Params

• task function - an async function

aah.CatchError ⇒ function

  let task = CatchError(task);

  const { error, result } = await task(request);

Kind: static property of aah
Returns: function - an async wrapper function around the task
Params

• task function - an async function to wrap around with a catch wrapper.

aah.Delay ⇒ function

	const task = Delay(1000);

	const result = await task(1); // result is 1, after 1 second

Kind: static property of aah
Returns: function - an async function
Params

• time number - the time to delay

aah.InOrder ⇒ function

	const task = InOrder(
		async (i) => i + 1,
		async (i) => i + 1,
		async (i) => i + 1
	);

	const results = await task(0); // results is 3

Kind: static property of aah
Returns: function - an async wrapper function that runs all of the tasks in order, calling each one with original request
Params

• ...tasks function - any number of async tasks.

aah.InParallel ⇒ function

	const task = InParallel(
		async (i) => i + 1,
		async (i) => i + 2,
		async (i) => i + 3
	);

	const results = await task(0); // results is [1, 2, 3]

Kind: static property of aah
Returns: function - an async wrapper function that runs all the tasks in parallel, and returns an array of results
Params

• ...tasks function - any number of async tasks.

aah.InSeries ⇒ function

	const task = InSeries(
		async (i) => i + 1,
		async (i) => i + 1,
		async (i) => i + 1
	);

	const results = await task(0); // results is 3

Kind: static property of aah
Returns: function - an async wrapper function that runs all of the tasks in series, calling each one with the results of the previous one
Params

• ...tasks function - any number of async tasks.

aah.ParallelFilter ⇒ function

	const task = ParallelFilter(
		async (val, i) => val % 2 === 0
	);

	const results = await task([0, 1, 2]); // results is [0, 2]

Kind: static property of aah
Returns: function - an async wrapper function that takes in an array of requests, runs the task in parallel, once for each input in the array, and returns an array of results
Params

• task function - the filtering task

aah.ParallelMap ⇒ function

	const task = ParallelMap(
		async (val, i) => val + 1
	);

	const results = await task([0, 1, 2]); // results is [1, 2, 3]

Kind: static property of aah
Returns: function - an async wrapper function that takes in an array of requests, runs the task in parallel, once for each input in the array, and returns an array of results
Params

• task function - the mapping task

aah.PassThrough

	const task = PassThrough;

	const results = await task(0); // results is 0

PassThrough does nothing, just passes the request through as the result

Kind: static property of aah

aah.Promisify ⇒ function

	const task = Promisify(
		(onDone, i) => onDone(
			i === 0 ? new Error('i cant be 0') : null,
			i + 1
		),
	);

	const results = await task(1); // results is 2
	const results2 = await taks(0); // throws 'i cant be 0 Error

Kind: static property of aah
Returns: function - an async function
Params

• task function - a callback-expecting function

aah.Race ⇒ function

	const task = Race(
		async (i) => i + 1,
		async (i) => i + 2,
	);

	const result = await task(1); // 2

Kind: static property of aah
Returns: function - an async task that resolves or rejects as soon as the first one of its "children" resolves or rejects
Params

• ...tasks function - any number of async tasks

aah.TimeIn ⇒ function

	const task = TimeIn(async (i) => i + 1, 1000);

	const result = await task(1); // result1 = 2, after 1000 ms

Kind: static property of aah
Returns: function - an async task
Params

• task function - an async task
• timeIn function - the minimum time the task can take

aah.TimeOut ⇒ function

	const task1 = TimeOut( Delay(100), 1000);
	const task2 = TimeOut( Delay(1000), 100);

	const result1 = await task1(1); // result1 = 1, after 100 ms
	const result2 = await task2(1); // throws a timeout error after 100 ms

Kind: static property of aah
Returns: function - an async task
Params

• task function - an async tasks
• timeOut function - the number of ms before throwing an error

aah.Assert(validator, message) ⇒ taskFunction

Builds an async assertion task. When called, if the arguments do not match the validator functions,

Kind: static method of aah
Returns: taskFunction - an assertion task
Params

• validator function - a function that checks the request.
• message string - an optional error message to throw if the assertion fails, or a message builder function.

aah.Logging(...statements) ⇒ function

A logging utility. It passes the request received into all the statements, collects the results, and pushes them into console.log

Kind: static method of aah
Returns: function - a logging task
Params

• ...statements * - any number of logging values. Functions are called with the calling request, everything else is passed directly to