add typing for compare locations helper

mohsen1 · mohsen1 · commit 413e1c9a709c · 2018-05-20T00:16:33.000-07:00
diff --git a/lib/compareLocations.js b/lib/compareLocations.js
@@ -3,6 +3,26 @@
 	Author Tobias Koppers @sokra
 */
 "use strict";
+
+/**
+ * @typedef {Object} LineAndColumn
+ * @property {number=} line
+ * @property {number=} column
+ */
+
+/**
+ * @typedef {Object} NodeLocation
+ * @property {LineAndColumn=} start
+ * @property {LineAndColumn=} end
+ * @property {number=} index
+ */
+
+/**
+ * Compare two locations
+ * @param {string|NodeLocation} a
+ * @param {string|NodeLocation} b
+ * @returns {-1|0|1}
+ */
 module.exports = (a, b) => {
 	if (typeof a === "string") {
 		if (typeof b === "string") {
