From 5b39d4b2da3cda2137db7cc68b595ba27ca2c214 Mon Sep 17 00:00:00 2001
From: Hugh Willson <hugh@octonary.com>
Date: Tue, 25 Jul 2017 21:32:42 -0400
Subject: [PATCH] Remove merged in underscore usage and update to ES5/ES6.

---
 packages/ejson/ejson.js | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/packages/ejson/ejson.js b/packages/ejson/ejson.js
index b989e3b124..9102083739 100644
--- a/packages/ejson/ejson.js
+++ b/packages/ejson/ejson.js
@@ -105,22 +105,31 @@ const builtinConverters = [
     },
   },
   { // RegExp
-    matchJSONValue: function (obj) {
-      return _.has(obj, '$regexp') && _.has(obj, '$flags') && _.size(obj) === 2;
+    matchJSONValue(obj) {
+      return hasOwn(obj, '$regexp')
+        && hasOwn(obj, '$flags')
+        && Object.keys(obj).length === 2;
     },
-    matchObject: function (obj) {
+    matchObject(obj) {
       return obj instanceof RegExp;
     },
-    toJSONValue: function (regexp) {
-      return { $regexp: regexp.source, $flags: regexp.flags };
+    toJSONValue(regexp) {
+      return {
+        $regexp: regexp.source,
+        $flags: regexp.flags
+      };
+    },
+    fromJSONValue(obj) {
+      // Replaces duplicate / invalid flags.
+      return new RegExp(
+        obj.$regexp,
+        obj.$flags
+          // Cut off flags at 50 chars to avoid abusing RegExp for DOS.
+          .slice(0, 50)
+          .replace(/[^gimuy]/g,'')
+          .replace(/(.)(?=.*\1)/g, '')
+      );
     },
-    fromJSONValue: function (obj) {
-      // replaces duplicate / invalid flags
-      // cut of flags to 50 chars to avoid abusing regex for DOS
-      return new RegExp(obj.$regexp, obj.$flags.substr(0, 50)
-                                               .replace(/[^gimuy]/g,'')
-                                               .replace(/(.)(?=.*\1)/g, ''));
-    }
   },
   { // NaN, Inf, -Inf. (These are the only objects with typeof !== 'object'
     // which we match.)