feat: Test for existing watchman trigger before installing one

jj-vcs · Jun 12, 2024 · 7cd52b1 · 7cd52b1
1 parent 20c12dc
commit 7cd52b1
Showing 1 changed file with 18 additions and 2 deletions.
diff --git a/lib/src/fsmonitor.rs b/lib/src/fsmonitor.rs
@@ -187,7 +187,9 @@ pub mod watchman {
             };
 
             if kind == super::FsmonitorKind::WatchmanTrigger {
-                monitor.register_trigger().await?;
+                if !monitor.is_trigger_registered().await? {
+                    monitor.register_trigger().await?;
+                }
             }
             Ok(monitor)
         }
@@ -245,6 +247,20 @@ 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> {
+            info!("Checking for an existing Watchman trigger...");
+            Ok(self
+                .client
+                .list_triggers(&self.resolved_root)
+                .await
+                .map_err(Error::WatchmanTriggerError)?
+                .triggers
+                .iter()
+                .any(|t| t.name == "jj-background-monitor"))
+        }
+
         /// Register trigger for changed files.
         #[instrument(skip(self))]
         async fn register_trigger(&self) -> Result<(), Error> {
@@ -255,7 +271,7 @@ pub mod watchman {
                 .register_trigger(
                     &self.resolved_root,
                     TriggerRequest {
-                        name: format!("jj-trigger-{:?}", self.resolved_root.path()),
+                        name: "jj-background-monitor".to_string(),
                         command: vec!["jj".to_string(), "st".to_string()],
                         expression: Some(self.build_exclude_expr()),
                         ..Default::default()