Sort groups in a list view

group.js

// sorts therapy groups by name, therapist and topic and adds therapist data to the payload 

const EMPTY_ARRAY = [];

export function processGroups(groups = EMPTY_ARRAY, therapists = EMPTY_ARRAY) {
  const groupsLength = groups.length;
  const therapistsLength = therapists.length;
  const groupsWithTherapistData = [];

  function defaultGroupSort(groups = []) {
    return groups.sort((a, b) => {
      const compareName = a.name.localeCompare(b.name);
      const compareTherapist = a.therapist.first.localeCompare(b.therapist.first);
      const compareTopic = a.topic.localeCompare(b.topic);

      return compareName || compareTherapist || compareTopic;
    });
  }

  function groupByGroupSchedule(groups = []) {
    const STRING_LENGTH_TO_COMPARE_IF_SAME_GROUP = 17;

    return groups.reduce(
      (acc, item) => {
        const groupNameForComparison = item.name.slice(0, STRING_LENGTH_TO_COMPARE_IF_SAME_GROUP);
        const hasOtherSchedule = groups
          .filter(g => g.id !== item.id)
          .some(g => g.name.includes(groupNameForComparison));

        if (hasOtherSchedule) {
          acc[0] = [...acc[0], item];
        } else {
          acc[1] = [...acc[1], item];
        }

        return acc;
      },
      [[], []],
    );
  }

  for (let i = 0; i < groupsLength; i++) {
    for (let j = 0; j < therapistsLength; j++) {
      if (groups[i].therapist === therapists[j].username) {
        groupsWithTherapistData.push({
          ...groups[i],
          therapist: therapists[j], // add therapist details to the group
          hasStarted: hasGroupStarted(groups[i].starts),
        });
      }
    }
  }

  const [groupsWithMoreScheduleOptions, groupsSingleSchedule] = groupByGroupSchedule(groupsWithTherapistData);

  return [...defaultGroupSort(groupsWithMoreScheduleOptions), ...defaultGroupSort(groupsSingleSchedule)];
}