javascript: Function to compare different .env files

compareEnvs.js

/*
 * Created: 14/1/2022  by Jakub Zomerfeld / dev.zomerfeld@gmail.com
 */

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

/**
 *
 * // IFFE Function to check existing env files and compare their keys and validate
 */
;(() => {
    const envExt = '.env'
    const envConfigFile = `${envExt}.config`

    const envsToCompareWithConfig = [`${envExt}`]

    const envFilesArray = envsToCompareWithConfig.map(
        (item, index) => envsToCompareWithConfig[index]
    )

    const parsedEnvFiles = envFilesArray.map(envFileName =>
        parseFile(envFileName)
    )

    if (
        !compareEnvKeyArrays(
            returnEnvKeys(parseFile(envConfigFile)),
            ...parsedEnvFiles.map((item, index) =>
                returnEnvKeys(parsedEnvFiles[index])
            )
        )
    ) {
        throw new Error(
            `There is a mismatch between: (${Object.values(
                envFilesArray
            )}) env files, compare existing variables.`
        )
    }

    console.log(
        `%cDEBUG: Env are identical between ${envConfigFile} and other: [${Object.values(
            envFilesArray
        )}] files`,
        'color: green; background: white;'
    )
})()

/**
 *
 * //Function to read file and parse it by 'dotenv' by fileName
 * @param {string} fileName
 * @return {File}
 */
function parseFile(fileName) {
    return dotenv.parse(fs.readFileSync(path.resolve('./', fileName)))
}

/**
 * //Function to compare arrays of env keys
 *
 * @param {array:keys} configEnvArray
 * @param {array} args array of different .env files keys
 * @return {boolean}
 */
function compareEnvKeyArrays(configEnvArray, ...args) {
    const booleanArray = args.map((item, index) => {
        const compare = JSON.stringify(configEnvArray) === JSON.stringify(item)
        if (!compare) {
            const difference = returnArraysDifference(configEnvArray, item)

            console.warn(
                `Mismatch between .env.config & array provided on index [${index}]. Difference: [${difference}]`
            )
        }

        return compare
    })

    return booleanArray.every(value => value)
}

/**
 *
 * //Function to get array of keys from env
 * @param {File} envFile
 * @return {array}
 */
function returnEnvKeys(envFile) {
    return Object.keys(envFile)
}

/**
 *
 * //Function to get difference between two arrays
 * @param {array} firstArray
 * @param {array} secondArray
 * @return {array}
 */
function returnArraysDifference(firstArray, secondArray) {
    return firstArray.filter(x => !secondArray.includes(x))
}