@onehilltech/dab/lib/resolvers/slice.js

a complex data builder that uses simple definitions

/*
 * Copyright (c) 2018 One Hill Technologies, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

const { slice, isFunction } = require ('lodash');

module.exports = function (_array, _start, _end) {
  return async function __dabSlice () {
    const [array, start, end] = await Promise.all ([
      this.resolve (_array),
      this.resolve (_start),
      this.resolve (_end)
    ]);

    if (array === undefined || isFunction (start) || isFunction (end))
      return undefined;

    return slice (array, start, end);
  };
};