Simple convert an object of styles into #inlineStyle #CSS string

toinline.js

const style = {
  width: 400,
  height: 300,
  position: 'fixed',
  top: 900,
  left: 60,
  'z-index': 1234
}

const inline = Object.entries(style).reduce((prev, curr) => {
  let [attr, val] = curr;
  const attrWithoutUnit = ['z-index'];
  if (Number.isInteger(val) && !attrWithoutUnit.includes(attr)) {
    val += 'px';
  } 
  return prev += `${attr}: ${val}; `;
}, '');

const getInlineStyles = (styles) => {
    return Object.entries(styles).reduce((prev, curr) => {
    // eslint-disable-next-line
    let [attr, val] = curr;
    const attrWithoutUnit = ['z-index'];
    if (Number.isInteger(val) && !attrWithoutUnit.includes(attr)) {
      val += 'px';
    }
    // eslint-disable-next-line
    return prev += `${attr}: ${val}; `;
  }, '');
};