From e036d4b53fc8c102931f2694f79a5a943f8a005d Mon Sep 17 00:00:00 2001
From: SleepingCrows <milo@sleepingcro.ws>
Date: Thu, 15 Aug 2024 19:09:33 -0400
Subject: [PATCH] Added Lowercase & Invisible Hashtag Policies

---
 policy.ts | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/policy.ts b/policy.ts
index de5bffc..529a45b 100644
--- a/policy.ts
+++ b/policy.ts
@@ -3,9 +3,40 @@ import { AntiDuplicationPolicy, HashtagPolicy, PubkeyBanPolicy, RegexPolicy, Key
 
 const kv = await Deno.openKv();
 
+export class LowercaseHashtagPolicy implements NPolicy {
+  async call(event: NostrEvent): Promise<NostrRelayOK> {
+    for (const [name, value] of event.tags) {
+      if (name === 't' && value !== value.toLowerCase()) {
+        return ['OK', event.id, false, 'blocked: uppercase letters in t tag'];
+      }
+    }
+
+    return ['OK', event.id, true, ''];
+  }
+}
+
+export class InvisibleHashtagPolicy implements NPolicy {
+  async call(event: NostrEvent): Promise<NostrRelayOK> {
+    if (event.kind === 1) {
+      const content = event.content.toLowerCase();
+
+      for (const [name, value] of event.tags) {
+        if (name === 't' && !content.includes(`#${value.toLowerCase()}`)) {
+          return ['OK', event.id, false, 'blocked: invisible hashtag'];
+        }
+      }
+    }
+
+    return ['OK', event.id, true, ''];
+  }
+}
+
+
 export default class AppPolicy implements NPolicy {
   async call(event: NostrEvent): Promise<NostrRelayOK> {
     const policy = new PipePolicy([
+      new LowercaseHashtagPolicy(),
+      new InvisibleHashtagPolicy(),
       new RegexPolicy(/This is a post from *(.+)!/igm),
       new KeywordPolicy([
         'NSFW sexual content',
@@ -268,3 +299,5 @@ export default class AppPolicy implements NPolicy {
     return policy.call(event);
   }
 }
+
+