From ea2a78add2dd984bbb7375448cc8a375ad62c967 Mon Sep 17 00:00:00 2001
From: wojciechkepka <wojtek.kepka@protonmail.com>
Date: Wed, 16 Jun 2021 19:36:13 +0200
Subject: [PATCH] Add error reply to server if document is missing

---
 helix-lsp/src/lib.rs          | 13 ++++++++++---
 helix-term/src/application.rs | 19 ++++++++++++++++++-
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 877fed668a821..15e94ce8277c8 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -246,7 +246,7 @@ impl Notification {
 
 #[derive(Debug)]
 pub struct Registry {
-    inner: HashMap<LanguageId, Arc<Client>>,
+    inner: HashMap<LanguageId, (usize, Arc<Client>)>,
 
     counter: AtomicUsize,
     pub incoming: SelectAll<UnboundedReceiverStream<(usize, Call)>>,
@@ -267,6 +267,13 @@ impl Registry {
         }
     }
 
+    pub fn get_by_id(&mut self, id: usize) -> Option<&Client> {
+        self.inner
+            .values()
+            .find(|(client_id, _)| client_id == &id)
+            .map(|(_, client)| client.as_ref())
+    }
+
     pub fn get(&mut self, language_config: &LanguageConfiguration) -> Result<Arc<Client>> {
         if let Some(config) = &language_config.language_server {
             // avoid borrow issues
@@ -274,7 +281,7 @@ impl Registry {
             let s_incoming = &mut self.incoming;
 
             match inner.entry(language_config.scope.clone()) {
-                Entry::Occupied(language_server) => Ok(language_server.get().clone()),
+                Entry::Occupied(entry) => Ok(entry.get().1.clone()),
                 Entry::Vacant(entry) => {
                     // initialize a new client
                     let id = self.counter.fetch_add(1, Ordering::Relaxed);
@@ -284,7 +291,7 @@ impl Registry {
                     s_incoming.push(UnboundedReceiverStream::new(incoming));
                     let client = Arc::new(client);
 
-                    entry.insert(client.clone());
+                    entry.insert((id, client.clone()));
                     Ok(client)
                 }
             }
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 033d93611d7e6..49ce9345f3361 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -345,7 +345,24 @@ impl Application {
                                 helix_lsp::block_on(server.reply(id, Ok(serde_json::Value::Null)));
                             }
                             None => {
-                                log::warn!("missing document with language server id {}", server_id)
+                                if let Some(server) =
+                                    self.editor.language_servers.get_by_id(server_id)
+                                {
+                                    log::warn!(
+                                        "missing document with language server id `{}`",
+                                        server_id
+                                    );
+                                    helix_lsp::block_on(server.reply(
+                                        id,
+                                        Err(helix_lsp::jsonrpc::Error {
+                                            code: helix_lsp::jsonrpc::ErrorCode::InternalError,
+                                            message: "document missing".to_string(),
+                                            data: None,
+                                        }),
+                                    ));
+                                } else {
+                                    log::warn!("can't find language server with id `{}`", server_id);
+                                }
                             }
                         }
                     }