Reduce the Complexity of a Function

original.js

// a function that does too many things
function showPrice(row, standardPrice, discountPrice, savings, isProrated, isDeferred) {

  var priceCol = row.find('td.price').eq(0);
  var discountCol = row.find('td.price').eq(1);
  var txt = '';

  if (!discountPrice && !standardPrice && !savings && !isProrated && !isDeferred) {
    discountCol.html('<img src="/img/loading.gif" />');
  } else {
    if (discountPrice && (standardPrice == discountPrice)) {
      priceCol.html('');
    } else {
      priceCol.html('<del>' + standardPrice + '</del>');
    }

    txt = '<strong>';

    if (discountPrice == '$0.00') {
      txt += 'FREE!';
    }

    if (isProrated) {
      txt += '*';
    } else if (isDeferred) {
      txt += '**';
    }

    txt += '</strong>';
  }

  discountCol.html(txt);
}

showPrice(row, null, null, null, null, null);

refactored.js

// sane-er code
var priceInfo = {
  isProrated: true
};
var priceHtml = getPrice(priceInfo);
var discountHtml = getDiscount(priceInfo);

updateRow(row, priceHtml, discountHtml);

function getDiscount(priceInfo) {
  var txt;

  if (priceInfo.discountPrice && priceInfo.standardPrice && priceInfo.savings && priceInfo.isProrated && priceInfo.isDeferred) {

    if (priceInfo.discountPrice == '$0.00') {
      txt += 'FREE!';
    }
    if (priceInfo.isProrated) {
      txt += '*';
    } else if (priceInfo.isDeferred) {
      txt += '**';
    }

    return '<strong>' + txt + '</strong>';
  }

  return '<img src="/img/loading.gif" />';
}

function getPrice(priceInfo) {
  if (!priceInfo.standardPrice) {
    return '';
  }

  if (priceInfo.standardPrice == priceInfo.discountPrice) {
    return '';
  }

  return '<del>' + priceInfo.standardPrice + '</del>';
}

function updateRow(row, priceHtml, discountHtml) {
  row.find('td.price').eq(0).html(priceHtml);
  row.find('td.price').eq(1).html(discountHtml);
}