Как заменить все новые строки после чтения файла

var input = 'a,b,c,d,e,f';
input = input.replace(/$/mg, ",");
console.info(input);

let str = `a,b,c,d,e,f
,,,,,
g,h,i,j,k,l`

let op = str.replace(/$/mg, "$&"+ ',')

console.info(op)

let text = `a,b,c,d,e,f
,,,,,
g,h,i,j,k,l`;

let edited = text.replace(/\s+/g, '');

console.info( edited )

// Let us have some sentences havin linebreaks as \n.

let statements = " Programming is so cool. \n We love to code. \n We can built what we want. \n :)";

// We will console it and see that they are working fine.
console.info(statements);

// We may replace the string via various methods which are as follows,

// FIRST IS USING SPLIT AND JOIN
let statementsWithComma1 = statements.split("\n").join(",");

// RESULT
console.info("RESULT1 : ", statementsWithComma1);

// SECOND IS USING REGEX
let statementsWithComma2 = statements.replace(/\n/gi, ',');

// RESULT
console.info("RESULT2 : ", statementsWithComma2);

// THIRS IS USING FOR LOOP
let statementsWithComma3 = "";

for(let i=0; i < statements.length; i++){
  if (statements[i] === "\n")
    statementsWithComma3 += ','
  else
    statementsWithComma3 += statements[i]
}

// RESULT
console.info("RESULT3 : ", statementsWithComma3);