From c9b3d64ce50e57d17151d8ad0851aff0801d9f22 Mon Sep 17 00:00:00 2001
From: Matt Kulukundis <matt.fowles@gmail.com>
Date: Thu, 20 Jun 2024 10:29:29 -0400
Subject: [PATCH] Add background snapshotting info to `debug watchman status`.

---
 cli/src/commands/debug/watchman.rs | 46 +++++++++++++++++++++++-------
 lib/src/fsmonitor.rs               |  4 +--
 lib/src/local_working_copy.rs      | 29 +++++++++++++++++++
 3 files changed, 66 insertions(+), 13 deletions(-)

diff --git a/cli/src/commands/debug/watchman.rs b/cli/src/commands/debug/watchman.rs
index dfb1faf8f4..908b613fab 100644
--- a/cli/src/commands/debug/watchman.rs
+++ b/cli/src/commands/debug/watchman.rs
@@ -46,28 +46,52 @@ pub fn cmd_debug_watchman(
     match subcommand {
         WatchmanCommand::Status => {
             // TODO(ilyagr): It would be nice to add colors here
-            match command.settings().fsmonitor_settings()? {
-                FsmonitorSettings::Watchman { .. } => {
-                    writeln!(ui.stdout(), "Watchman is enabled via `core.fsmonitor`.")?
+            let config = match command.settings().fsmonitor_settings()? {
+                FsmonitorSettings::Watchman(config) => {
+                    writeln!(ui.stdout(), "Watchman is enabled via `core.fsmonitor`.")?;
+                    writeln!(
+                        ui.stdout(),
+                        r"Background snapshotting is {}. Use `core.watchman.register_snapshot_trigger` to control it.",
+                        if config.register_trigger {
+                            "enabled"
+                        } else {
+                            "disabled"
+                        }
+                    )?;
+                    config
+                }
+                FsmonitorSettings::None => {
+                    writeln!(
+                        ui.stdout(),
+                        r#"Watchman is disabled. Set `core.fsmonitor="watchman"` to enable."#
+                    )?;
+                    writeln!(
+                        ui.stdout(),
+                        "Attempting to contact the `watchman` CLI regardless..."
+                    )?;
+                    WatchmanConfig::default()
                 }
-                FsmonitorSettings::None => writeln!(
-                    ui.stdout(),
-                    "Watchman is disabled. Set `core.fsmonitor=\"watchman\"` to \
-                     enable.\nAttempting to contact the `watchman` CLI regardless..."
-                )?,
                 other_fsmonitor => {
                     return Err(user_error(format!(
-                        "This command does not support the currently enabled filesystem monitor: \
-                         {other_fsmonitor:?}."
+                        r"This command does not support the currently enabled filesystem monitor: {other_fsmonitor:?}."
                     )))
                 }
             };
             let wc = check_local_disk_wc(workspace_command.working_copy().as_any())?;
-            let _ = wc.query_watchman(&WatchmanConfig::default())?;
+            let _ = wc.query_watchman(&config)?;
             writeln!(
                 ui.stdout(),
                 "The watchman server seems to be installed and working correctly."
             )?;
+            writeln!(
+                ui.stdout(),
+                "Background snapshotting is currently {}.",
+                if wc.is_watchman_trigger_registered(&config)? {
+                    "active"
+                } else {
+                    "inactive"
+                }
+            )?;
         }
         WatchmanCommand::QueryClock => {
             let wc = check_local_disk_wc(workspace_command.working_copy().as_any())?;
diff --git a/lib/src/fsmonitor.rs b/lib/src/fsmonitor.rs
index 0fff7a9c95..c4152159d8 100644
--- a/lib/src/fsmonitor.rs
+++ b/lib/src/fsmonitor.rs
@@ -30,7 +30,7 @@ use crate::settings::ConfigResultExt;
 #[derive(Default, Eq, PartialEq, Clone, Debug)]
 pub struct WatchmanConfig {
     /// Whether to use triggers to monitor for changes in the background.
-    register_trigger: bool,
+    pub register_trigger: bool,
 }
 
 /// The recognized kinds of filesystem monitors.
@@ -260,7 +260,7 @@ pub mod watchman {
 
         /// Return whether or not a trigger has been registered already.
         #[instrument(skip(self))]
-        async fn is_trigger_registered(&self) -> Result<bool, Error> {
+        pub async fn is_trigger_registered(&self) -> Result<bool, Error> {
             info!("Checking for an existing Watchman trigger...");
             Ok(self
                 .client
diff --git a/lib/src/local_working_copy.rs b/lib/src/local_working_copy.rs
index e4c417e6c8..55a7ed6771 100644
--- a/lib/src/local_working_copy.rs
+++ b/lib/src/local_working_copy.rs
@@ -739,6 +739,22 @@ impl TreeState {
         Ok(changed_files)
     }
 
+    #[cfg(feature = "watchman")]
+    #[tokio::main(flavor = "current_thread")]
+    #[instrument(skip(self))]
+    pub async fn is_watchman_trigger_registered(
+        &self,
+        config: &WatchmanConfig,
+    ) -> Result<bool, TreeStateError> {
+        let fsmonitor = watchman::Fsmonitor::init(&self.working_copy_path, config)
+            .await
+            .map_err(|err| TreeStateError::Fsmonitor(Box::new(err)))?;
+        fsmonitor
+            .is_trigger_registered()
+            .await
+            .map_err(|err| TreeStateError::Fsmonitor(Box::new(err)))
+    }
+
     /// Look for changes to the working copy. If there are any changes, create
     /// a new tree from it and return it, and also update the dirstate on disk.
     #[instrument(skip_all)]
@@ -1696,6 +1712,19 @@ impl LocalWorkingCopy {
                 err: err.into(),
             })
     }
+
+    #[cfg(feature = "watchman")]
+    pub fn is_watchman_trigger_registered(
+        &self,
+        config: &WatchmanConfig,
+    ) -> Result<bool, WorkingCopyStateError> {
+        self.tree_state()?
+            .is_watchman_trigger_registered(config)
+            .map_err(|err| WorkingCopyStateError {
+                message: "Failed to query watchman".to_string(),
+                err: err.into(),
+            })
+    }
 }
 
 pub struct LocalWorkingCopyFactory {}