css-rule-set-to-string.js

/* @flow */

import appendPxIfNeeded from './append-px-if-needed';
import camelCasePropsToDashCase from './camel-case-props-to-dash-case';
import mapObject from './map-object';
import {getPrefixedStyle} from './prefixer';

function createMarkupForStyles(style: Object): string {
  return Object.keys(style)
    .map(property => {
      return property + ': ' + style[property] + ';';
    })
    .join('\n');
}

export default function cssRuleSetToString(
  selector: string,
  rules: Object,
  userAgent: ?string
): string {
  if (!rules) {
    return '';
  }

  const rulesWithPx = mapObject(rules, (value, key) =>
    appendPxIfNeeded(key, value)
  );
  const prefixedRules = getPrefixedStyle(rulesWithPx, userAgent);
  const cssPrefixedRules = camelCasePropsToDashCase(prefixedRules);
  const serializedRules = createMarkupForStyles(cssPrefixedRules);
  return selector + '{' + serializedRules + '}';
}