send custom emoji

crates/chat_ui/Cargo.toml

@@ -25,4 +25,5 @@ serde.workspace = true
 
 linkify = "0.10.0"
 pulldown-cmark = "0.13.1"
+regex = "1"
 

crates/chat_ui/src/lib.rs

@@ -1,5 +1,5 @@
 use std::collections::{BTreeMap, HashMap, HashSet};
-use std::sync::{Arc, RwLock};
+use std::sync::{Arc, LazyLock, RwLock};
 
 pub use actions::*;
 use anyhow::{Context as AnyhowContext, Error};
@@ -17,6 +17,7 @@ use gpui::{
 use itertools::Itertools;
 use nostr_sdk::prelude::*;
 use person::{Person, PersonRegistry};
+use regex::Regex;
 use settings::{AppSettings, SignerKind};
 use smallvec::{SmallVec, smallvec};
 use state::{NostrRegistry, upload};
@@ -38,6 +39,11 @@ use crate::text::RenderedText;
 const REACTION_EMOJIS: &[&str] = &["👍", "👎", "😄", "🎉", "😕", "❤️", "🚀", "👀"];
 const COMPACT_REACTION_EMOJIS: &[&str] = &["👍", "❤️", "👀"];
 
+/// Regex matching strings that consist entirely of emoji characters,
+/// zero-width joiners, variation selectors, and keycap combiners.
+static EMOJI_RE: LazyLock<Regex> =
+    LazyLock::new(|| Regex::new(r"^[\p{Emoji}\u{200D}\u{FE0F}\u{20E3}]+$").unwrap());
+
 mod actions;
 mod text;
 
@@ -361,6 +367,17 @@ impl ChatPanel {
             return;
         }
 
+        // If replying to exactly one message with only a valid emoji,
+        // send as a reaction instead of a text message
+        if replies.len() == 1 && EMOJI_RE.is_match(&content) && self.attachments.read(cx).is_empty()
+        {
+            for reply in &replies {
+                self.send_reaction(&content, reply, window, cx);
+            }
+            self.clear(window, cx);
+            return;
+        }
+
         self.send_message(&content, replies, false, window, cx);
     }