Test coverage and headless nvim bug fixes

nvim-core/src/headless.rs

@@ -21,6 +21,9 @@ pub async fn spawn_headless_nvim() -> Result<String, String> {
         .arg("--headless")
         .arg("--listen")
         .arg(&socket_name)
+        .stdin(std::process::Stdio::piped())
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
         .kill_on_drop(true)
         .spawn()
         .map_err(|e| format!("Failed to spawn headless Neovim: {}", e))?;
@@ -40,3 +43,13 @@ pub async fn spawn_headless_nvim() -> Result<String, String> {
 
     Ok(socket_name)
 }
+
+pub async fn kill_headless_nvim() {
+    let child_to_kill = {
+        let mut proc_lock = HEADLESS_PROC.lock().unwrap_or_else(|e| e.into_inner());
+        proc_lock.take()
+    };
+    if let Some(mut child) = child_to_kill {
+        let _ = child.kill().await;
+    }
+}