@sugarcube/plugin-csv/_dist/plugins/export.js

CSV based input and output for SugarCube.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _fp = require("lodash/fp");

var _fs = _interopRequireDefault(require("fs"));

var _csvStringify = _interopRequireDefault(require("csv-stringify"));

var _core = require("@sugarcube/core");

var _assertions = require("../assertions");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

// Prefix keys in a list of pairs with a string and return it as an object,
// e.g.: prefixPairsToObj('xx', [[0, 'a'], [1, 'b']]) => {xx_0: 'a', xx_1; 'b'}
// Prefixing the namespace and turning a list of pairs to an object are handled
// in one pass for performance reasons.
const namespacePairsToObj = (0, _fp.curry)((ns, pairs) => (0, _fp.reduce)((memo, [k, v]) => (0, _fp.merge)(memo, {
  [`${ns}_${k}`]: v
}), {}, pairs)); // lodash provides already `toPairs` for objects. This creates pairs of index
// positions and values for arrays, e.g.:
// toAryPairs(['a', 'b']) => [[0, 'a'], [1, 'b']].

const toAryPairs = xs => (0, _fp.zip)((0, _fp.range)(0, (0, _fp.size)(xs)), xs); // Create a flat version of a nested unit, e.g.:
// flatten({a: {b: 23, c: {a: 42}}, b: [1, 2], c: 23}) =>
//         {a_b: 23, a_c_a: 42, b_0: 1, b_1: 2, c: 23}


const flatten = unit => (0, _fp.reduce)((memo, [key, value]) => {
  const iter = (0, _fp.flow)([namespacePairsToObj(key), flatten]);
  const flattenObj = (0, _fp.flow)([_fp.toPairs, iter]);
  const flattenAry = (0, _fp.flow)([toAryPairs, iter]);

  switch (value) {
    case (0, _fp.isPlainObject)(value) ? value : null:
      {
        return (0, _fp.merge)(memo, flattenObj(value));
      }

    case (0, _fp.isArray)(value) ? value : null:
      {
        return (0, _fp.merge)(memo, flattenAry(value));
      }

    case (0, _fp.isDate)(value) ? value : null:
      {
        return (0, _fp.merge)(memo, {
          [key]: value.toISOString()
        });
      }

    default:
      {
        return (0, _fp.merge)(memo, {
          [key]: value
        });
      }
  }
}, {}, (0, _fp.toPairs)(unit)); // `flattenAndExpand` iterates over the whole input data and creates flat
// objects from nested objects, while collecting all keynames. For performance
// reasons, this happens in one pass.
// flattenAndExpand([{a: 23}, {a: 23, b: {c: 42}}]) =>
//                  [[{a: 23}, {a: 23, b_c: 42}], [a, b_c]]


const flattenAndExpand = (0, _fp.reduce)(([flatUnits, uniqKeys], unit) => {
  const keyNames = (0, _fp.flow)([_fp.keys, (0, _fp.concat)(uniqKeys), _fp.uniq]);
  const flattenedUnit = flatten(unit);
  return [(0, _fp.concat)(flatUnits, flattenedUnit), keyNames(flattenedUnit)];
}, [[], []]);

const exportPlugin = (val, {
  cfg,
  log
}) => {
  const filename = (0, _fp.get)("csv.filename", cfg);
  const delimiter = (0, _fp.get)("csv.delimiter", cfg);
  const skipEmpty = (0, _fp.get)("csv.skip_empty", cfg);

  if (skipEmpty && (0, _fp.size)(val.data) === 0) {
    log.info("Data pipeline is empty. Skip the export.");
    return val;
  }

  log.info(`Converting to csv and writing to ${filename}.`);
  log.debug(`Converting ${(0, _fp.size)(val.data)} units to CSV.`);
  const [data, keyNames] = flattenAndExpand(val.data); // The template is an object with all possible keys. I use it later to expand
  // objects that miss some keys.

  const template = (0, _fp.reduce)((memo, k) => (0, _fp.merge)(memo, {
    [k]: null
  }), {}, keyNames); // Pipe the csv stream into the file.

  const csv = (0, _csvStringify.default)({
    header: true,
    quotedString: true,
    delimiter
  });
  csv.pipe(_fs.default.createWriteStream(filename)); // eslint-disable-next-line promise/avoid-new

  return new Promise((resolve, reject) => {
    csv.on("error", reject);
    csv.on("finish", () => resolve(val)); // Avoid lodash forEach to have eager evaluation.

    data.forEach(r => csv.write((0, _fp.merge)(template, r)));
    csv.end();
  });
};

const plugin = _core.plugin.liftManyA2([_assertions.assertFilename, exportPlugin]);

plugin.desc = "Export data units to a file in CSV format.";
plugin.argv = {
  "csv.filename": {
    default: "out.csv",
    nargs: 1,
    desc: "The file name to write the CSV to"
  },
  "csv.skip_empty": {
    type: "boolean",
    desc: "Skip export of empty data pipelines."
  }
};
var _default = plugin;
exports.default = _default;