csvToJson.js

const fs = require('fs')
const path = require('path')

function parseCsvLinesToArray(file) {
    const matchLineBreak = /\r?\n/
    return file.toString().trim().split(matchLineBreak)
}

function composeMatchingCsvColumnRegex(csvColumns) {
    const csvColumnToNamedCapturingGroup = (currentColumn, currentIndex, array) => {
        const isLastIndex = currentIndex + 1 === array.length
        const shouldAddSeparator = isLastIndex === false
        return `(?<${currentColumn}>.+)${shouldAddSeparator ? ',' : ''}`
    }
    
    const matchCsvColumnStringPattern = csvColumns.map(csvColumnToNamedCapturingGroup).join("")
    return new RegExp(matchCsvColumnStringPattern);
}

function convertCsvToJson(csvPath) {
    const csvFile = fs.readFileSync(csvPath)
    const csvFileAsArray = parseCsvLinesToArray(csvFile)
    
    const [headerRow] = csvFileAsArray.splice(0, 1)
    const csvColumns = headerRow.split(',')
    const matchRowDataRegex = composeMatchingCsvColumnRegex(csvColumns)
    
    return csvFileAsArray.map((currentRow) => {
        const matchInfo = currentRow.match(matchRowDataRegex);
        return matchInfo.groups
    })
}

function exportJsonFile(jsonCollection) {
    const outputDirPath = path.join(__dirname, 'output')
    if (!fs.existsSync(outputDirPath)) fs.mkdirSync(outputDirPath);
    
    const outputPath = path.join(__dirname, 'output', 'mock.json')
    fs.writeFileSync(outputPath, JSON.stringify(jsonCollection))
    console.log(`File available at:\n${outputPath}`);
}

const filePath = path.join(__dirname, 'data', 'data.csv')
const result = convertCsvToJson(filePath)

exportJsonFile(result)