Improve MineGeo exploration and mapping features

shared/server-address.ts

@@ -0,0 +1,32 @@
+/** Compare the address players enter in Minecraft; never resolve DNS aliases. */
+export function normalizeServerAddress(
+  value: string | null | undefined,
+): string | null {
+  const input = value?.trim().toLowerCase();
+  if (!input) return null;
+  if (input.length > 255) throw new Error("Server address is too long");
+  const match = /^(\[[0-9a-f:]+\]|[a-z0-9.-]+)(?::([0-9]{1,5}))?$/.exec(input);
+  if (!match)
+    throw new Error("Use a Minecraft hostname or IP, with an optional port");
+  let host = match[1];
+  if (host.startsWith("[")) {
+    try {
+      new URL(`http://${host}`);
+    } catch {
+      throw new Error("Invalid IPv6 address");
+    }
+  } else {
+    host = host.replace(/\.$/, "");
+    if (
+      host.length > 253 ||
+      host
+        .split(".")
+        .some((label) => !/^[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?$/.test(label))
+    )
+      throw new Error("Invalid server hostname");
+  }
+  const port = match[2] ? Number(match[2]) : 25565;
+  if (port < 1 || port > 65535)
+    throw new Error("Server port must be between 1 and 65535");
+  return host + (port === 25565 ? "" : `:${port}`);
+}