Resolve completions properly remotely

crates/project/src/lsp_store.rs

@@ -1759,7 +1759,6 @@ impl LspStore {
             buffer_id: buffer_id.into(),
         };
 
-        // TODO kb this has to return the entire LSP completion instead, not just the docs
         let Some(response) = client
             .request(request)
             .await
@@ -1768,6 +1767,10 @@ impl LspStore {
         else {
             return;
         };
+        let Some(lsp_completion) = serde_json::from_slice(&response.lsp_completion).log_err()
+        else {
+            return;
+        };
 
         let documentation = if response.documentation.is_empty() {
             Documentation::Undocumented
@@ -1784,6 +1787,7 @@ impl LspStore {
         let mut completions = completions.write();
         let completion = &mut completions[completion_index];
         completion.documentation = Some(documentation);
+        completion.lsp_completion = lsp_completion;
 
         let old_range = response
             .old_start
@@ -4189,17 +4193,32 @@ impl LspStore {
         let lsp_completion = serde_json::from_slice(&envelope.payload.lsp_completion)?;
 
         let completion = this
-            .read_with(&cx, |this, _| {
+            .read_with(&cx, |this, cx| {
                 let id = LanguageServerId(envelope.payload.language_server_id as usize);
                 let Some(server) = this.language_server_for_id(id) else {
                     return Err(anyhow!("No language server {id}"));
                 };
 
-                Ok(server.request::<lsp::request::ResolveCompletionItem>(lsp_completion))
+                Ok(cx.background_executor().spawn(async move {
+                    let can_resolve = server
+                        .capabilities()
+                        .completion_provider
+                        .as_ref()
+                        .and_then(|options| options.resolve_provider)
+                        .unwrap_or(false);
+                    if can_resolve {
+                        server
+                            .request::<lsp::request::ResolveCompletionItem>(lsp_completion)
+                            .await
+                    } else {
+                        anyhow::Ok(lsp_completion)
+                    }
+                }))
             })??
             .await?;
 
         let mut documentation_is_markdown = false;
+        let lsp_completion = serde_json::to_string(&completion)?.into_bytes();
         let documentation = match completion.documentation {
             Some(lsp::Documentation::String(text)) => text,
 
@@ -4241,6 +4260,7 @@ impl LspStore {
             old_start,
             old_end,
             new_text,
+            lsp_completion,
         })
     }
 

crates/proto/proto/zed.proto

@@ -1219,6 +1219,7 @@ message ResolveCompletionDocumentationResponse {
     Anchor old_start = 3;
     Anchor old_end = 4;
     string new_text = 5;
+    bytes lsp_completion = 6;
 }
 
 message ResolveInlayHint {