feathers-casl/src/utils/simplifyQuery.ts

Add access control with CASL to your feathers application.

import _isEqual from 'lodash/isEqual.js'
import _cloneDeep from 'lodash/cloneDeep.js'

import type { Query } from '@feathersjs/feathers'

export const simplifyQuery = <Q extends Query | null>(
  query: Q,
  replaceAnd = true,
  replaceOr = true,
): Q => {
  if (!query) {
    return query
  }
  if (!query.$and && !query.$or) {
    return query
  }
  let result = _cloneDeep(query)

  if (result.$and && !result.$and.length) {
    delete result.$and
  }

  if (result.$or && !result.$or.length) {
    delete result.$or
  }

  /*if (result.$and && result.$or) {
    const or = (result.$or.length > 1) ? { $or: result.$or } : result.$or[0];
    result.$and.push(or);
    delete result.$or;
  }*/

  if (result.$and) {
    const $and: any[] = []
    result.$and.forEach((q: any) => {
      q = simplifyQuery(q, true, true)
      if ($and.some((x) => _isEqual(x, q))) return
      $and.push(q)
    })
    if (replaceAnd && $and.length === 1 && Object.keys(result).length === 1) {
      result = $and[0]
    } else {
      result.$and = $and
    }
  }
  if (result.$or) {
    const $or: any[] = []
    result.$or.forEach((q: any) => {
      q = simplifyQuery(q, true, true)
      if ($or.some((x) => _isEqual(x, q))) return
      $or.push(q)
    })
    if (replaceOr && $or.length === 1 && Object.keys(result).length === 1) {
      result = $or[0]
    } else {
      result.$or = $or
    }
  }
  return result
}