Improve code quality and write tests

node_modules/unicode-match-property-ecmascript/index.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const canonicalProperties = require('unicode-canonical-property-names-ecmascript');
+const propertyAliases = require('unicode-property-aliases-ecmascript');
+
+const matchProperty = function(property) {
+	if (canonicalProperties.has(property)) {
+		return property;
+	}
+	if (propertyAliases.has(property)) {
+		return propertyAliases.get(property);
+	}
+	throw new Error(`Unknown property: ${ property }`);
+};
+
+module.exports = matchProperty;