todo-txt-cli/src/sorter.js

A CLI for todo.txt files - http://todotxt.org/

/**
 * @typedef {(a: Record<string, any>, b: Record<string, any>) => number} ObjectSorter
 */
/**
 * @typedef {(property: string) => ObjectSorter} Sorter
 */

const noneSorter = (_a, _b) => 0

const undef = (a, b) => (!a && !b ? 0 : !a ? 1 : !b ? -1 : undefined)

/**
 * @param {string} p
 * @returns {ObjectSorter}
 */
export const numSorter = (p) => (a, b) => undef(a[p], b[p]) ?? a[p] - b[p]

/**
 * keeps sorting order if both object use property `p`
 * @param {string} p
 * @returns {ObjectSorter}
 */
export const boolSorter = (p) => (a, b) =>
  a[p] && b[p] ? 1 : a[p] ? 1 : b[p] ? -1 : 0

/**
 * @param {string} p
 * @returns {ObjectSorter}
 */
export const stringSorter = (p) => (a, b) =>
  undef(a[p], b[p]) ?? a[p].localeCompare(b[p])

export const sortSet = (set) =>
  set ? [...set].sort((a, b) => a.localeCompare(b)) : []

/**
 * set values are sorted, concatenated and compared
 * @param {string} p
 * @returns {ObjectSorter}
 */
const setSorter = (p) => (a, b) => {
  const aset = sortSet(a[p]).join(',')
  const bset = sortSet(b[p]).join(',')
  return undef(aset, bset) ?? aset.localeCompare(bset)
}

export const sorting = {
  due: ['isCompleted', 'dueAt', 'priority', 'projects', 'contexts', 'task'],
  pri: ['isCompleted', 'priority', 'dueAt', 'task'],
  prj: ['isCompleted', 'projects', 'priority', 'dueAt', 'contexts', 'task'],
  con: ['isCompleted', 'contexts', 'priority', 'dueAt', 'projects', 'task'],
  task: ['isCompleted', 'task']
}

/** @type {Record<string, ObjectSorter>} */
const _sorters = {
  id: stringSorter('id'),
  contexts: setSorter('contexts'),
  createdAt: numSorter('createdAt'),
  dueAt: numSorter('dueAt'),
  isCompleted: boolSorter('isCompleted'),
  priority: stringSorter('priority'),
  projects: setSorter('projects'),
  task: stringSorter('task')
}

/**
 * @param {string[]} sortOrder
 * @param {Record<string,ObjectSorter>} [sorters]
 * @returns
 */
export const sorter =
  (sortOrder, sorters = _sorters) =>
  (a, b) => {
    let result = 0
    for (const prop of sortOrder) {
      let fn = sorters[prop] || noneSorter
      result = fn(a, b)
      if (result !== 0) {
        break
      }
    }
    return result
  }