CSV Parser for AWS DynamoDB

csvtojson.js

const csv = require('csvtojson');
const fs = require('fs');

const files = [];

const colParserBool = item => {
  return item === "true";
};

const colParserStringSet = item => {
  let trimmed = item.trim();

  trimmed = trimmed.replace(/^{ \"/, "");
  trimmed = trimmed.replace(/\" }$/, "");

  const arr = trimmed.split("\", \"").map(x => x.trim());
  return arr;
};

const type_match = {
    "N": "number",
    "S": "string",
    "BOOL": colParserBool,
    "SS": colParserStringSet
}

const get_clean_header = header => (header.replace(/\s\([A-Z]+\)$/, ""));

const filename_to_json = filename => (filename.replace(/.csv$/, ".json"));

const run = async () => {
  for (const file of files) {
    const header_type_matches = {};

    const csv_parser_header = csv();
    csv_parser_header.on('header', header => {
      for (let i = 0; i < header.length; ++i) {
        const header_col = header[i];

        const [_, type] = /\s\(([A-Z]+)\)$/.exec(header_col);
        const name_clean = get_clean_header(header_col);

        header[i] = name_clean;
        header_type_matches[name_clean] = type_match[type];
      }
    });

    await csv_parser_header.fromFile(file);

    const csv_parser = csv({
      colParser: header_type_matches
    }).on('header', header => {
      header = header.map((x, i) => {
        header[i] = get_clean_header(x)
      });
    });

    const obj = await csv_parser.fromFile(file);

    fs.writeFileSync(filename_to_json(file), JSON.stringify(obj, null, 2));
  }
}

run();