make re2 secretly optional

Author: vicary

package.json

@@ -17,7 +17,7 @@
   ],
   "dependencies": {
     "ip-regex": "^4.3.0",
-    "re2": "^1.15.9",
+    "re2": "^1.16.0",
     "tlds": "^1.217.0"
   },
   "devDependencies": {

src/index.js

@@ -1,9 +1,14 @@
-const RE2 = require('re2');
 const ipRegex = require('ip-regex');
 const tlds = require('tlds');
 
 /* istanbul ignore next */
-const SafeRegExp = typeof RE2 === 'function' ? RE2 : RegExp;
+const SafeRegExp = (() => {
+  try {
+    return require('re2');
+  } catch {
+    return RegExp;
+  }
+})();
 const ipv4 = ipRegex.v4().source;
 const ipv6 = ipRegex.v6().source;