From c8a32c873f5378b63cbeefe2a59f9b4f3f259aac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A1t=C3=A9=20Szab=C3=B3?= <mszabo@slack-corp.com>
Date: Thu, 7 May 2026 17:22:04 +0200
Subject: [PATCH] Add more logging around watchman

Ensure we emit info logs for all file changes events we process,
and simplify ownership of the watchman receiver on the server thread,
complaining if the subscriber goes away.

Also remove the now-unnecessary stdio redirection for servers spawned
by the LSP server.
---
 src/language_server/server_client.rs | 10 ++--------
 src/server/lib.rs                    | 20 +++++++++-----------
 src/server/watchman.rs               |  3 +++
 3 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/src/language_server/server_client.rs b/src/language_server/server_client.rs
index dba8a692..0d27d53a 100644
--- a/src/language_server/server_client.rs
+++ b/src/language_server/server_client.rs
@@ -97,20 +97,14 @@ impl ServerConnection {
             project_root.display()
         );
 
-        let log_path = std::env::temp_dir().join("hakana-server.log");
-        let stdout = std::fs::File::create(&log_path)?;
-        let stderr = stdout.try_clone()?;
-
-        log::info!("Server log file: {}", log_path.display());
-
         let child = Command::new(&binary)
             .arg("server")
             .arg("--root")
             .arg(project_root)
             .current_dir(project_root)
             .stdin(Stdio::null())
-            .stdout(Stdio::from(stdout))
-            .stderr(Stdio::from(stderr))
+            .stdout(Stdio::null())
+            .stderr(Stdio::null())
             .spawn()
             .map_err(|e| {
                 io::Error::new(
diff --git a/src/server/lib.rs b/src/server/lib.rs
index c20272f9..7d398cbd 100644
--- a/src/server/lib.rs
+++ b/src/server/lib.rs
@@ -22,6 +22,8 @@ use std::sync::atomic::AtomicU32;
 use std::sync::{Arc, Mutex, MutexGuard};
 use std::time::Instant;
 
+use crate::watchman::WatchmanHandle;
+
 #[derive(Clone)]
 pub struct ServerConfig {
     pub root_dir: String,
@@ -54,7 +56,6 @@ pub struct Server {
     socket: ServerSocket,
     state: Arc<Mutex<ServerState>>,
     start_time: Instant,
-    watchman_handle: Option<watchman::WatchmanHandle>,
     config_changed: bool,
     analysis_rx:
         tokio::sync::broadcast::Receiver<Result<Arc<(AnalysisResult, SuccessfulScanData)>, String>>,
@@ -100,7 +101,6 @@ impl Server {
             socket,
             state: Arc::new(Mutex::new(ServerState::new())),
             start_time: Instant::now(),
-            watchman_handle: None,
             config_changed: false,
             analysis_rx,
             analysis_tx,
@@ -131,12 +131,11 @@ impl Server {
             watchman_clock,
             config_path,
         );
-        self.watchman_handle = Some(handle);
 
-        self.main_loop().await
+        self.main_loop(handle).await
     }
 
-    async fn main_loop(&mut self) -> io::Result<()> {
+    async fn main_loop(&mut self, mut watchman: WatchmanHandle) -> io::Result<()> {
         info!("Performing initial analysis...");
 
         {
@@ -182,13 +181,12 @@ impl Server {
                         }
                     }
                 }
-                Some(event) = async {
-                    match self.watchman_handle.as_mut() {
-                        Some(handle) => handle.recv().await,
-                        None => std::future::pending().await,
+                watchman_event = watchman.recv() => {
+                    if let Some(event) = watchman_event {
+                        self.handle_watchman_event(event);
+                    } else {
+                        log::error!("watchman subscriber is not active");
                     }
-                } => {
-                    self.handle_watchman_event(event);
                 }
                 result = self.analysis_rx.recv() => {
                     self.handle_analysis_result(result);
diff --git a/src/server/watchman.rs b/src/server/watchman.rs
index 39b6917f..0569522a 100644
--- a/src/server/watchman.rs
+++ b/src/server/watchman.rs
@@ -214,6 +214,7 @@ async fn handle_subscription_event(
 
                 // Config changed triggers full re-analysis, so send it first
                 if config_changed {
+                    log::info!("Watchman detected config file change, triggering full reanalysis");
                     if tx.send(WatchmanEvent::ConfigChanged).await.is_err() {
                         log::info!("Server shut down, stopping watchman subscription");
                         return false;
@@ -231,6 +232,8 @@ async fn handle_subscription_event(
                         return false;
                     }
                 }
+            } else {
+                log::info!("Received watchman file changes event without files");
             }
         }
         Ok(SubscriptionData::StateEnter { state_name, .. }) => {