util: refactor debuglog() from array regex to regex string

lib/util.js

@@ -230,28 +230,30 @@ function format(f) {
   return str;
 }
 
-var debugs = {};
-var debugEnviron;
+const debugs = {};
+let debugEnviron;
 
 const regExpSpecialChars = /[|\\{}()[\]^$+?.]/g;
 
-function stringToRegExp(string) {
+function arrayToRegExp(strArr) {
   // Escape special chars except wildcard.
-  string = string.replace(regExpSpecialChars, '\\$&');
-  // Transform wildcard to "match anything"
-  string = string.replace(/\*/g, '.*');
-  return new RegExp(`^${string}$`);
+  strArr = strArr.map((str) => {
+    return str.replace(regExpSpecialChars, '\\$&')
+      .replace(/\*/g, '.*');
+  });
+
+  return new RegExp(strArr.join('|'), 'i');
 }
 
 function debuglog(set) {
   if (debugEnviron === undefined) {
     debugEnviron = Array.from(new Set(
       (process.env.NODE_DEBUG || '').split(',').map((s) => s.toUpperCase())));
-    debugEnviron = debugEnviron.map(stringToRegExp);
   }
   set = set.toUpperCase();
   if (!debugs[set]) {
-    if (debugEnviron.some((name) => name.test(set))) {
+    const regex = arrayToRegExp(debugEnviron);
+    if (regex.test(set)) {
       var pid = process.pid;
       debugs[set] = function() {
         var msg = exports.format.apply(exports, arguments);