flow like the river

VISUALIZACION/node_modules/polished/lib/helpers/remToPx.js

@@ -0,0 +1,61 @@
+"use strict";
+
+exports.__esModule = true;
+exports["default"] = remToPx;
+var _getValueAndUnit = _interopRequireDefault(require("./getValueAndUnit"));
+var _errors = _interopRequireDefault(require("../internalHelpers/_errors"));
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
+var defaultFontSize = 16;
+function convertBase(base) {
+  var deconstructedValue = (0, _getValueAndUnit["default"])(base);
+  if (deconstructedValue[1] === 'px') {
+    return parseFloat(base);
+  }
+  if (deconstructedValue[1] === '%') {
+    return parseFloat(base) / 100 * defaultFontSize;
+  }
+  throw new _errors["default"](78, deconstructedValue[1]);
+}
+function getBaseFromDoc() {
+  /* eslint-disable */
+  /* istanbul ignore next */
+  if (typeof document !== 'undefined' && document.documentElement !== null) {
+    var rootFontSize = getComputedStyle(document.documentElement).fontSize;
+    return rootFontSize ? convertBase(rootFontSize) : defaultFontSize;
+  }
+  /* eslint-enable */
+  /* istanbul ignore next */
+  return defaultFontSize;
+}
+
+/**
+ * Convert rem values to px. By default, the base value is pulled from the font-size property on the root element (if it is set in % or px). It defaults to 16px if not found on the root. You can also override the base value by providing your own base in % or px.
+ * @example
+ * // Styles as object usage
+ * const styles = {
+ *   'height': remToPx('1.6rem')
+ *   'height': remToPx('1.6rem', '10px')
+ * }
+ *
+ * // styled-components usage
+ * const div = styled.div`
+ *   height: ${remToPx('1.6rem')}
+ *   height: ${remToPx('1.6rem', '10px')}
+ * `
+ *
+ * // CSS in JS Output
+ *
+ * element {
+ *   'height': '25.6px',
+ *   'height': '16px',
+ * }
+ */
+function remToPx(value, base) {
+  var deconstructedValue = (0, _getValueAndUnit["default"])(value);
+  if (deconstructedValue[1] !== 'rem' && deconstructedValue[1] !== '') {
+    throw new _errors["default"](77, deconstructedValue[1]);
+  }
+  var newBase = base ? convertBase(base) : getBaseFromDoc();
+  return deconstructedValue[0] * newBase + "px";
+}
+module.exports = exports.default;