booking a resource

booking.js

const flatten = arrays => [].concat.apply([], arrays);
const bookTime = (resource, time) => {
  const newResource = resource.map(t => {
    return (t.start < time.start && time.end < t.end)
      ? [{start: t.start, end: time.start}, {start: time.end, end: t.end}]
      : t;
  });

  return flatten(newResource);
};

const makeBooking = (resource, time) => {
  const newResource = bookTime(resource, time);
  return {
    ok: newResource.length === resource.length + 1,
    resource: newResource
  }
};

const testResource = [
  {start: 1, end: 9}
];

const booking = {start: 2, end: 8};
const result = makeBooking(testResource, booking);

// No output is a good thing :-)
//
console.assert(result.ok === true);

console.assert(result.resource[0].start === 1);
console.assert(result.resource[0].end === 2);

console.assert(result.resource[1].start === 8);
console.assert(result.resource[1].end === 9);