Allow LSP server to be stopped (helix-editor#5964)

Author: davxy

book/src/generated/typable-cmd.md

@@ -49,6 +49,7 @@
 | `:update` | Write changes only if the file has been modified. |
 | `:lsp-workspace-command` | Open workspace command picker |
 | `:lsp-restart` | Restarts the Language Server that is in use by the current doc |
+| `:lsp-stop` | Stops the Language Server that is in use by the current doc |
 | `:tree-sitter-scopes` | Display tree sitter scopes, primarily for theming and development. |
 | `:debug-start`, `:dbg` | Start a debug session from a given template with given parameters. |
 | `:debug-remote`, `:dbg-tcp` | Connect to a debug adapter by TCP address and start a debugging session from a given template with given parameters. |

helix-lsp/src/lib.rs

@@ -476,6 +476,16 @@ impl Registry {
         }
     }
 
+    pub fn stop(&mut self, language_config: &LanguageConfiguration) {
+        let scope = language_config.scope.clone();
+
+        if let Some((_, client)) = self.inner.remove(&scope) {
+            tokio::spawn(async move {
+                let _ = client.force_shutdown().await;
+            });
+        }
+    }
+
     pub fn get(
         &mut self,
         language_config: &LanguageConfiguration,

helix-term/src/commands/typed.rs

@@ -1354,6 +1354,37 @@ fn lsp_restart(
     Ok(())
 }
 
+fn lsp_stop(
+    cx: &mut compositor::Context,
+    _args: &[Cow<str>],
+    event: PromptEvent,
+) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    let doc = doc!(cx.editor);
+
+    let ls_id = doc
+        .language_server()
+        .map(|ls| ls.id())
+        .context("LSP not running for the current document")?;
+
+    let config = doc
+        .language_config()
+        .context("LSP not defined for the current document")?;
+    cx.editor.language_servers.stop(config);
+
+    for doc in cx.editor.documents_mut() {
+        if doc.language_server().map_or(false, |ls| ls.id() == ls_id) {
+            doc.set_language_server(None);
+            doc.set_diagnostics(Default::default());
+        }
+    }
+
+    Ok(())
+}
+
 fn tree_sitter_scopes(
     cx: &mut compositor::Context,
     _args: &[Cow<str>],
@@ -2349,6 +2380,13 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
             fun: lsp_restart,
             completer: None,
         },
+        TypableCommand {
+            name: "lsp-stop",
+            aliases: &[],
+            doc: "Stops the Language Server that is in use by the current doc",
+            fun: lsp_stop,
+            completer: None,
+        },
         TypableCommand {
             name: "tree-sitter-scopes",
             aliases: &[],