parse-csv.js

import fs from "node:fs/promises";

/**
 * read a csv file
 * @param {string} filename - the name of the CSV file
 * @param {string} delimiter - delimiter of the CSV file, defaults to ','
 * @returns Array<string[]>
 * */
export default async function parseCSV(filename, delimiter = ",") {
  const result = await fs.readFile(filename, { encoding: "utf8" });

  const rows = [];
  for (const row of result.split("\n")) {
    rows.push(row.split(delimiter));
  }

  return rows;
}

   import fs from "node:fs"

/**
 * parse a CSV file with node stream
 * @param {string} filename - name of file to be read
 * @returns {Promise<Array<string[]>>} 
 * */
export default function parseCSVWithStream(filename) {
  return new Promise((resolve, reject) => {
    const reader = fs.createReadStream(filename, {'encoding': "utf-8"})

    let rows = []

    reader.on("error", (err) => reject(err))
    reader.on("data", (data) => {
      const row = data.toString().trim()
      rows.push(row)
    })

    reader.on("end", () => {
      rows = rows.join("").split("\n")
      const result = rows.map((row) => row.split(","))
      resolve(result)
    })
  })
}