@onehilltech/dab/lib/resolvers/concat.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 {
  concat,
  isFunction,
  some
} = require ('lodash');

module.exports = function (...arrays) {
  return function __dabConcat () {
    return this.resolve (arrays).then (arrays => {
      if (arrays === undefined)
        return undefined;

      if (some (arrays, value => (value === undefined || isFunction (value))))
        return undefined;

      return concat (...arrays);
    });
  };
};