Convert JS style object to injectable CSS

css.js

function toKebabCase(string) {
  return string.replace(/([a-z0-9]|(?=[A-Z]))([A-Z])/g, '$1-$2').toLowerCase();
}

function hash(string) {
  var h = 0
  var i = 0;

  if (string.length > 0) {
    while (i < string.length) {
      h = (h << 5) - h + string.charCodeAt(i++) | 0;
    }
  }
  
  return h;
}

var unitless = [
  'z-index',
  'font-weight',
  'line-height',
  'counter-reset',
  'counter-increment',
  'volume',
  'stress',
  'pitch-range',
  'richness',
];

function css(style) {
  var output = '{';

  style && Object.keys(style).forEach(function (key) {
    var property = toKebabCase(key);
    var value = style[key];
    
    if (typeof value === 'number' && value > 0 && !unitless.includes(property)) {
      value += 'px';
    }
    
    output += `\n\t${property}: ${value};`
  });
  
  output += `\n}`;
  
  var className = hash(JSON.stringify(style));
  
  return `.css-${className} ${output}`;
}

var style = {
  margin: 10,
  color: 'red',
  padding: '20px',
  fontFamily: '"Roboto", sans-serif',
};

console.log(css(style));