feat(react-property): add module that exports isCustomAttribute

Author: remarkablemark

packages/react-property/src/is-custom-attribute.js

@@ -0,0 +1,19 @@
+var ATTRIBUTE_NAME_START_CHAR =
+  ':A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD';
+
+var ATTRIBUTE_NAME_CHAR =
+  ATTRIBUTE_NAME_START_CHAR + '\\-.0-9\\u00B7\\u0300-\\u036F\\u203F-\\u2040';
+
+/**
+ * Checks whether a property name is a custom attribute.
+ *
+ * @see https://github.com/facebook/react/blob/15-stable/src/renderers/dom/shared/HTMLDOMPropertyConfig.js#L23-L25
+ *
+ * @param {String}
+ * @return {Boolean}
+ */
+var isCustomAttribute = RegExp.prototype.test.bind(
+  new RegExp('^(data|aria)-[' + ATTRIBUTE_NAME_CHAR + ']*$')
+);
+
+module.exports = isCustomAttribute;