internal: Reply to requests with defaults when vfs is still loading

Author: Veykril

Cargo.toml

@@ -4,7 +4,7 @@ exclude = ["crates/proc-macro-srv/proc-macro-test/imp"]
 resolver = "2"
 
 [workspace.package]
-rust-version = "1.78"
+rust-version = "1.80"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 authors = ["rust-analyzer team"]

crates/rust-analyzer/src/handlers/dispatch.rs

@@ -97,16 +97,45 @@ impl RequestDispatcher<'_> {
         self
     }
 
-    /// Dispatches a non-latency-sensitive request onto the thread pool.
+    /// Dispatches a non-latency-sensitive request onto the thread pool. When the VFS is marked not
+    /// ready this will return a default constructed [`R::Result`].
     pub(crate) fn on<const ALLOW_RETRYING: bool, R>(
         &mut self,
         f: fn(GlobalStateSnapshot, R::Params) -> anyhow::Result<R::Result>,
     ) -> &mut Self
     where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + panic::UnwindSafe + Send + fmt::Debug,
-        R::Result: Serialize,
+        R: lsp_types::request::Request<
+                Params: DeserializeOwned + panic::UnwindSafe + Send + fmt::Debug,
+                Result: Serialize + Default,
+            > + 'static,
+    {
+        if !self.global_state.vfs_done {
+            if let Some(lsp_server::Request { id, .. }) =
+                self.req.take_if(|it| it.method == R::METHOD)
+            {
+                self.global_state.respond(lsp_server::Response::new_ok(id, R::Result::default()));
+            }
+            return self;
+        }
+        self.on_with_thread_intent::<true, ALLOW_RETRYING, R>(ThreadIntent::Worker, f)
+    }
+
+    /// Dispatches a non-latency-sensitive request onto the thread pool. When the VFS is marked not
+    /// ready this will return the parameter as is.
+    pub(crate) fn on_identity<const ALLOW_RETRYING: bool, R, Params>(
+        &mut self,
+        f: fn(GlobalStateSnapshot, Params) -> anyhow::Result<R::Result>,
+    ) -> &mut Self
+    where
+        R: lsp_types::request::Request<Params = Params, Result = Params> + 'static,
+        Params: Serialize + DeserializeOwned + panic::UnwindSafe + Send + fmt::Debug,
     {
+        if !self.global_state.vfs_done {
+            if let Some((request, params, _)) = self.parse::<R>() {
+                self.global_state.respond(lsp_server::Response::new_ok(request.id, &params))
+            }
+            return self;
+        }
         self.on_with_thread_intent::<true, ALLOW_RETRYING, R>(ThreadIntent::Worker, f)
     }
 
@@ -198,11 +227,7 @@ impl RequestDispatcher<'_> {
         R: lsp_types::request::Request,
         R::Params: DeserializeOwned + fmt::Debug,
     {
-        let req = match &self.req {
-            Some(req) if req.method == R::METHOD => self.req.take()?,
-            _ => return None,
-        };
-
+        let req = self.req.take_if(|it| it.method == R::METHOD)?;
         let res = crate::from_json(R::METHOD, &req.params);
         match res {
             Ok(params) => {

crates/rust-analyzer/src/lsp/ext.rs

@@ -61,7 +61,7 @@ impl Request for FetchDependencyList {
 #[serde(rename_all = "camelCase")]
 pub struct FetchDependencyListParams {}
 
-#[derive(Deserialize, Serialize, Debug)]
+#[derive(Deserialize, Serialize, Debug, Default)]
 #[serde(rename_all = "camelCase")]
 pub struct FetchDependencyListResult {
     pub crates: Vec<CrateInfoResult>,
@@ -194,7 +194,7 @@ pub struct TestItem {
     pub runnable: Option<Runnable>,
 }
 
-#[derive(Deserialize, Serialize, Debug)]
+#[derive(Deserialize, Serialize, Debug, Default)]
 #[serde(rename_all = "camelCase")]
 pub struct DiscoverTestResults {
     pub tests: Vec<TestItem>,
@@ -690,6 +690,12 @@ pub enum ExternalDocsResponse {
     WithLocal(ExternalDocsPair),
 }
 
+impl Default for ExternalDocsResponse {
+    fn default() -> Self {
+        ExternalDocsResponse::Simple(None)
+    }
+}
+
 #[derive(Debug, Default, PartialEq, Serialize, Deserialize, Clone)]
 #[serde(rename_all = "camelCase")]
 pub struct ExternalDocsPair {

crates/rust-analyzer/src/main_loop.rs

@@ -173,8 +173,10 @@ impl GlobalState {
         }
 
         if self.config.discover_workspace_config().is_none() {
-            let req = FetchWorkspaceRequest { path: None, force_crate_graph_reload: false };
-            self.fetch_workspaces_queue.request_op("startup".to_owned(), req);
+            self.fetch_workspaces_queue.request_op(
+                "startup".to_owned(),
+                FetchWorkspaceRequest { path: None, force_crate_graph_reload: false },
+            );
             if let Some((cause, FetchWorkspaceRequest { path, force_crate_graph_reload })) =
                 self.fetch_workspaces_queue.should_start_op()
             {
@@ -545,6 +547,10 @@ impl GlobalState {
             let snapshot = self.snapshot();
             self.task_pool.handle.spawn_with_sender(ThreadIntent::LatencySensitive, {
                 let subscriptions = subscriptions.clone();
+                // Do not fetch semantic diagnostics (and populate query results) if we haven't even
+                // loaded the initial workspace yet.
+                let fetch_semantic =
+                    self.vfs_done && self.fetch_workspaces_queue.last_op_result().is_some();
                 move |sender| {
                     let diags = fetch_native_diagnostics(
                         &snapshot,
@@ -556,22 +562,29 @@ impl GlobalState {
                         .send(Task::Diagnostics(DiagnosticsTaskKind::Syntax(generation, diags)))
                         .unwrap();
 
-                    let diags = fetch_native_diagnostics(
-                        &snapshot,
-                        subscriptions,
-                        slice,
-                        NativeDiagnosticsFetchKind::Semantic,
-                    );
-                    sender
-                        .send(Task::Diagnostics(DiagnosticsTaskKind::Semantic(generation, diags)))
-                        .unwrap();
+                    if fetch_semantic {
+                        let diags = fetch_native_diagnostics(
+                            &snapshot,
+                            subscriptions,
+                            slice,
+                            NativeDiagnosticsFetchKind::Semantic,
+                        );
+                        sender
+                            .send(Task::Diagnostics(DiagnosticsTaskKind::Semantic(
+                                generation, diags,
+                            )))
+                            .unwrap();
+                    }
                 }
             });
             start = end;
         }
     }
 
     fn update_tests(&mut self) {
+        if !self.vfs_done {
+            return;
+        }
         let db = self.analysis_host.raw_database();
         let subscriptions = self
             .mem_docs
@@ -1052,9 +1065,9 @@ impl GlobalState {
             .on::<NO_RETRY, lsp_request::GotoImplementation>(handlers::handle_goto_implementation)
             .on::<NO_RETRY, lsp_request::GotoTypeDefinition>(handlers::handle_goto_type_definition)
             .on::<NO_RETRY, lsp_request::InlayHintRequest>(handlers::handle_inlay_hints)
-            .on::<NO_RETRY, lsp_request::InlayHintResolveRequest>(handlers::handle_inlay_hints_resolve)
+            .on_identity::<NO_RETRY, lsp_request::InlayHintResolveRequest, _>(handlers::handle_inlay_hints_resolve)
             .on::<NO_RETRY, lsp_request::CodeLensRequest>(handlers::handle_code_lens)
-            .on::<NO_RETRY, lsp_request::CodeLensResolve>(handlers::handle_code_lens_resolve)
+            .on_identity::<NO_RETRY, lsp_request::CodeLensResolve, _>(handlers::handle_code_lens_resolve)
             .on::<NO_RETRY, lsp_request::PrepareRenameRequest>(handlers::handle_prepare_rename)
             .on::<NO_RETRY, lsp_request::Rename>(handlers::handle_rename)
             .on::<NO_RETRY, lsp_request::References>(handlers::handle_references)
@@ -1081,7 +1094,7 @@ impl GlobalState {
             .on::<NO_RETRY, lsp_ext::Runnables>(handlers::handle_runnables)
             .on::<NO_RETRY, lsp_ext::RelatedTests>(handlers::handle_related_tests)
             .on::<NO_RETRY, lsp_ext::CodeActionRequest>(handlers::handle_code_action)
-            .on::<RETRY, lsp_ext::CodeActionResolveRequest>(handlers::handle_code_action_resolve)
+            .on_identity::<RETRY, lsp_ext::CodeActionResolveRequest, _>(handlers::handle_code_action_resolve)
             .on::<NO_RETRY, lsp_ext::HoverRequest>(handlers::handle_hover)
             .on::<NO_RETRY, lsp_ext::ExternalDocs>(handlers::handle_open_docs)
             .on::<NO_RETRY, lsp_ext::OpenCargoToml>(handlers::handle_open_cargo_toml)

docs/dev/lsp-extensions.md

@@ -1,5 +1,5 @@
 <!---
-lsp/ext.rs hash: e92e1f12229b0071
+lsp/ext.rs hash: 3429c08745984b3d
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue: