Reduce to ordened tuples of group and ordened values with lodash help

gist.js

[
	{ordernation: 2, category : 'A'}, {ordernation: 2, category : 'B'},
	{ordernation: 1, category : 'A'}, {ordernation: 1, category : 'B'},
	{ordernation: 3, category : 'C'}
]
.reduce(function (acc, it) {
	let tuple = acc.find(tuple => tuple[0] === it.category);
	if (tuple) {
		let list = tuple[1];
		list.splice(_.sortedIndexBy(list, it, 'ordernation'), 0, it)
	} else {
		let newTuple = [it.category, [it]];
		acc.splice(_.sortedIndexBy(acc, newTuple, '0'), 0, newTuple)
	}

	return acc;
}, [])

//[
//	['A', [{ordernation: 1, category : 'A'}, {ordernation: 2, category : 'A'}]],
//	['B', [{ordernation: 1, category : 'B'}, {ordernation: 2, category : 'B'}]],
//	['C', [{ordernation: 3, category : 'C'}]]
//]