From b021f7cdd43476609c2aa9e850aa67cf9d378d0f Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sun, 13 Aug 2017 12:21:56 -0700
Subject: [PATCH] util: minor.

---
 lib/utils/util.js | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/lib/utils/util.js b/lib/utils/util.js
index 84dd6c86..0e3659ea 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -183,7 +183,7 @@ util.isAscii = function isAscii(str) {
  */
 
 util.isBase58 = function isBase58(str) {
-  return typeof str === 'string' && /^[1-9a-zA-Z]+$/.test(str);
+  return typeof str === 'string' && /^[1-9A-Za-z]+$/.test(str);
 };
 
 /**
@@ -197,7 +197,7 @@ util.isBase58 = function isBase58(str) {
 util.isHex = function isHex(str) {
   if (typeof str !== 'string')
     return false;
-  return /^[0-9a-f]+$/i.test(str) && str.length % 2 === 0;
+  return str.length % 2 === 0 && /^[0-9A-Fa-f]+$/.test(str);
 };
 
 /**
@@ -358,7 +358,7 @@ util.error = function error(...args) {
 /**
  * Return hrtime (shim for browser).
  * @param {Array} time
- * @returns {Array}
+ * @returns {Array} [seconds, nanoseconds]
  */
 
 util.hrtime = function hrtime(time) {
@@ -372,9 +372,14 @@ util.hrtime = function hrtime(time) {
     }
 
     const ms = now % 1000;
-    const sec = (now - ms) / 1000;
 
-    return [sec, ms * 1e6];
+    // Seconds
+    const hi = (now - ms) / 1000;
+
+    // Nanoseconds
+    const lo = ms * 1e6;
+
+    return [hi, lo];
   }
 
   if (time) {
@@ -773,8 +778,11 @@ util.binaryRemove = function binaryRemove(items, item, compare) {
  */
 
 util.isUpperCase = function isUpperCase(str) {
+  assert(typeof str === 'string');
+
   if (str.length === 0)
     return false;
+
   return (str.charCodeAt(0) & 32) === 0;
 };
 
@@ -786,15 +794,14 @@ util.isUpperCase = function isUpperCase(str) {
  */
 
 util.startsWith = function startsWith(str, prefix) {
+  assert(typeof str === 'string');
+
+  if (!str.startsWith)
+    return str.indexOf(prefix) === 0;
+
   return str.startsWith(prefix);
 };
 
-if (!''.startsWith) {
-  util.startsWith = function startsWith(str, prefix) {
-    return str.indexOf(prefix) === 0;
-  };
-}
-
 /**
  * Get memory usage info.
  * @returns {Object}