Punycode & TLD handling in search

src/controllers/search.controller.ts

@@ -3,6 +3,11 @@ import isIp from "is-ip";
 import domainNameRegex from "domain-name-regex";
 import isAsn from "is-asn";
 import isCidr from "is-cidr";
+import punycode from "punycode";
+import isDomainName from "is-domain-name";
+
+const { Resolver } = require('dns').promises;
+const resolver = new Resolver();
 
 const router: Router = Router();
 
@@ -19,10 +24,46 @@ router.get("/", (req: Request, res: Response, next: NextFunction) => {
       res.redirect(`/${query}`);
     } else if(isCidr(query)) {
       res.redirect(`/net/${query}`);
-    } else if(domainNameRegex.test(query)) {
-      res.redirect(`/dns/${query}`);
+    } else if(domainNameRegex.test(punycode.toASCII(query))) {
+      res.redirect(`/dns/${punycode.toASCII(query)}`);
     } else {
-      res.send("Query: " + query);
+      /**
+       * TLD check
+       */
+      if(isDomainName(punycode.toASCII(query))) {
+        const tld = punycode.toASCII(query);
+
+        if(tld.toLowerCase() !== tld && tld.toUpperCase() !== tld) {
+          // If query is partially upper case, do not continue to TLD resolve.
+          //
+          // google -> TLD
+          // Google -> continue_search
+          // GOOGLE -> TLD
+          continue_search(query);
+        } else {
+          resolver.resolveNs(tld)
+            .then(addresses => {
+              if(addresses.length > 2) {
+                res.redirect(`/tld/${tld}`)
+              }
+            })
+            .catch(err => {
+              if(err.errno === "ENOTFOUND") {
+                // TLD not found
+                continue_search(query);
+              } else {
+                // DNS errors
+                next(err);
+              }
+            })
+        }
+      } else {
+        continue_search(query);
+      }
+
+      function continue_search(query) {
+        res.send("Query: " + query);
+      }
     }
   } else {
     next();