@nathanfaucett/parallel/src/fromObject.js

parallel for the browser and node.js

var keys = require("@nathanfaucett/keys"),
	once = require("@nathanfaucett/once"),
	asyncDone = require("@nathanfaucett/async_done"),
	objectValues = require("@nathanfaucett/values").objectValues,
	arrayForEach = require("@nathanfaucett/array-for_each"),
	throwIfNotFunction = require("./throwIfNotFunction");

module.exports = fromObject;

function fromObject(tasks) {
	var taskNames = keys(tasks),
		taskValues = objectValues(tasks, taskNames),
		taskLength = taskValues.length;

	arrayForEach(taskValues, throwIfNotFunction);

	return function runObject(callback) {
		var onceCallback = once(callback),
			results = {},
			count = taskLength;

		function onResult(error, key, result) {
			results[key] = result;

			if (error) {
				onceCallback(error, results);
			} else if (--count === 0) {
				onceCallback(undefined, results);
			}
		}

		arrayForEach(taskValues, function each(task, index) {
			asyncDone(task, function onAsyncDone(error, result) {
				onResult(error, taskNames[index], result);
			});
		});
	};
}