chore: refactor domain parsing to be more general (#3448)

* change the api of domain parsing to just parseDomain and getCookieDomain
* adds getBaseDomain as the method to get the domain after any official subdomains

shared/utils/urls.ts

@@ -1,32 +1,32 @@
+import env from "../env";
 import { parseDomain } from "./domains";
 
-const env = typeof window !== "undefined" ? window.env : process.env;
-
 export function cdnPath(path: string): string {
   return `${env.CDN_URL}${path}`;
 }
 
+// TODO: HACK: if this is called server-side, it will always return false.
+// - The only call sites to this function and isExternalUrl are on the client
+//   - The reason this is in a shared util is because it's used in an editor plugin
+//     which is also in the shared code
 export function isInternalUrl(href: string) {
+  // empty strings are never internal
+  if (href === "") {
+    return false;
+  }
+
+  // relative paths are always internal
   if (href[0] === "/") {
     return true;
   }
+
   const outline =
     typeof window !== "undefined"
       ? parseDomain(window.location.href)
       : undefined;
-  const parsed = parseDomain(href);
 
-  if (
-    parsed &&
-    outline &&
-    parsed.subdomain === outline.subdomain &&
-    parsed.domain === outline.domain &&
-    parsed.tld === outline.tld
-  ) {
-    return true;
-  }
-
-  return false;
+  const domain = parseDomain(href);
+  return outline?.host === domain.host;
 }
 
 export function isExternalUrl(href: string) {