hooks: answer each message, so the extension sends a report once

the pi extension (herdr's protocol) waits for a reply line and sends a
report again after 0.5 s without one; dingger never replied. every report
arrived twice and took about 2 s, delaying the next one (the live log: 196
of 400 reports repeated the previous one, 0.49 s later). the daemon now
answers each line with {"ok":true}; senders that do not read replies
(dingger poke, importance, the claude hook) are unaffected.

e2e step 21: one report, done in 0.38 s; without replies, two, 2.08 s.

2 files changed, 23 insertions, 0 deletions

diff --git a/crates/dinggerd/src/hooks.rs b/crates/dinggerd/src/hooks.rs
index 8b24659..a649fa0 100644
--- a/crates/dinggerd/src/hooks.rs
+++ b/crates/dinggerd/src/hooks.rs
@@ -18,6 +18,8 @@
 //! order, so a turn that starts and finishes between two polls is still a
 //! completion, and each report wakes the watcher immediately.
 //!
+//! Each line is answered with `{"ok":true}`.
+//!
 //! `{"method":"poke"}` only wakes the watcher; `dingger focus` and tmux's
 //! focus-change hooks send it so attendance updates without waiting for the
 //! next poll. The last reported state stays authoritative for its pane
@@ -123,8 +125,18 @@ struct HookParams {
 }
 
 fn handle_stream(stream: UnixStream) {
+    // Each message gets a reply line: an extension waits for one and sends
+    // the message again without it (herdr's protocol), so a report would
+    // arrive twice and take seconds.
+    let mut replies = stream.try_clone().ok();
     for line in BufReader::new(stream).lines() {
         let Ok(line) = line else { return };
+        if let Some(out) = replies.as_mut() {
+            use std::io::Write;
+            if out.write_all(b"{\"ok\":true}\n").is_err() {
+                replies = None; // the sender does not read replies
+            }
+        }
         let Ok(message) = serde_json::from_str::<HookMessage>(&line) else {
             warn!(%line, "invalid hook message");
             continue;
diff --git a/tests/e2e.sh b/tests/e2e.sh
index 20ce5dc..e51b18d 100755
--- a/tests/e2e.sh
+++ b/tests/e2e.sh
@@ -909,6 +909,17 @@ if command -v node >/dev/null; then
   expect "announced to other extensions" "grep -c '^event dingger:importance {\"level\":\"high\"}$' $EXTLOG" 1
   report "$I2" "" normal
   expect "imp: set back by hand" "opt $I2 @dingger_importance" ""
+  # Unanswered, the extension sends a report again after 0.5 s, and gives
+  # up on it after 2 s.
+  working() { sed 's/\x1b\[[0-9;]*m//g' "$DIR/daemon.log" | grep -c "hook report pane=$I2 state=Working"; }
+  before=$(working)
+  start=$(python3 -c 'import time; print(time.time())')
+  iext "$I2" agent_start
+  took=$(python3 -c 'import time,sys; print(round(time.time() - float(sys.argv[1]), 2))' "$start")
+  sleep 0.6
+  expect "the daemon answers a report: the extension sends it once" "echo \$((\$(working) - before))" 1
+  expect "and is done with it at once ($took s, with the harness's 0.3 s pause)" \
+    "python3 -c 'import sys; print(float(sys.argv[1]) < 1.5)' $took" True 1
   iext "$I2" session_start
   expect "a new pi on the session reports it again" "opt $I2 @dingger_importance" high
   # pi starts a session before any command runs.