tripitaka/lib/processors/index-fields.js

A low dependency, no frills logger, designed to play nicely with tools like fluentd and Elasticsearch

const has = require('has-value');
const get = require('get-value');
const set = require('set-value');

module.exports = (params = {}) => {
  const { field = 'fields', paths = [], reportComplexTypes = false } = params;
  return ({ record }) => {
    const index = indexFields(paths, record, reportComplexTypes);
    return { ...record, [field]: index };
  };
};

function indexFields(paths, record, reportComplexTypes) {
  return paths.reduce((index, path) => {
    if (!has(record, path)) return index;
    const value = get(record, path);

    if (isInvalidNumber(value)) return index;

    const complex = hasComplexType(value);
    if (complex && reportComplexTypes) throw new Error(`${path} cannot be indexed because it resolves to a complex type`);
    if (complex) return index;

    return set(index, path, value);
  }, {});
}

function isInvalidNumber(value) {
  return typeof value === 'number' && (!Number.isFinite(value) || Number.isNaN(value));
}

function hasComplexType(value) {
  if (value === null) return false;
  return ['object', 'function', 'symbol'].includes(typeof value);
}