Support textDocument/diagnostic specification (Pull diagnostics)

helix-core/src/syntax/config.rs

@@ -265,6 +265,7 @@ pub enum LanguageServerFeature {
     WorkspaceSymbols,
     // Symbols, use bitflags, see above?
     Diagnostics,
+    PullDiagnostics,
     RenameSymbol,
     InlayHints,
     DocumentColors,
@@ -289,6 +290,7 @@ impl Display for LanguageServerFeature {
             DocumentSymbols => "document-symbols",
             WorkspaceSymbols => "workspace-symbols",
             Diagnostics => "diagnostics",
+            PullDiagnostics => "pull-diagnostics",
             RenameSymbol => "rename-symbol",
             InlayHints => "inlay-hints",
             DocumentColors => "document-colors",

helix-lsp/src/client.rs

@@ -62,6 +62,7 @@ pub struct Client {
     initialize_notify: Arc<Notify>,
     /// workspace folders added while the server is still initializing
     req_timeout: u64,
+    ongoing_work: Mutex<Vec<(lsp::TextDocumentIdentifier, lsp::ProgressToken)>>,
 }
 
 impl Client {
@@ -258,6 +259,7 @@ impl Client {
             root_uri,
             workspace_folders: Mutex::new(workspace_folders),
             initialize_notify: initialize_notify.clone(),
+            ongoing_work: Mutex::new(Default::default()),
         };
 
         Ok((client, server_rx, initialize_notify))
@@ -372,6 +374,7 @@ impl Client {
                 Some(OneOf::Left(true) | OneOf::Right(_))
             ),
             LanguageServerFeature::Diagnostics => true, // there's no extra server capability
+            LanguageServerFeature::PullDiagnostics => capabilities.diagnostic_provider.is_some(),
             LanguageServerFeature::RenameSymbol => matches!(
                 capabilities.rename_provider,
                 Some(OneOf::Left(true)) | Some(OneOf::Right(_))
@@ -602,6 +605,9 @@ impl Client {
                         did_rename: Some(true),
                         ..Default::default()
                     }),
+                    diagnostic: Some(lsp::DiagnosticWorkspaceClientCapabilities {
+                        refresh_support: Some(true),
+                    }),
                     ..Default::default()
                 }),
                 text_document: Some(lsp::TextDocumentClientCapabilities {
@@ -679,6 +685,10 @@ impl Client {
                         }),
                         ..Default::default()
                     }),
+                    diagnostic: Some(lsp::DiagnosticClientCapabilities {
+                        dynamic_registration: Some(false),
+                        related_document_support: Some(true),
+                    }),
                     publish_diagnostics: Some(lsp::PublishDiagnosticsClientCapabilities {
                         version_support: Some(true),
                         tag_support: Some(lsp::TagSupport {
@@ -1229,6 +1239,75 @@ impl Client {
         Some(self.call::<lsp::request::RangeFormatting>(params))
     }
 
+    pub fn mark_work_as_done(&self, id: lsp::ProgressToken) {
+        self.ongoing_work.lock().retain(|x| x.1 != id);
+    }
+
+    fn cancel_ongoing_work(&self, id: lsp::ProgressToken) {
+        self.notify::<lsp::notification::Cancel>(lsp::CancelParams { id: id.clone() });
+        self.mark_work_as_done(id);
+    }
+
+    pub fn text_document_diagnostic(
+        &self,
+        text_document: lsp::TextDocumentIdentifier,
+        previous_result_id: Option<String>,
+    ) -> Option<(
+        impl Future<Output = Result<lsp::DocumentDiagnosticReportResult>>,
+        lsp::ProgressToken,
+    )> {
+        let capabilities = self.capabilities();
+
+        let ongoing_work = {
+            let ongoing_work_lock = self.ongoing_work.lock();
+
+            ongoing_work_lock
+                .iter()
+                .filter(|x| x.0 == text_document)
+                .cloned()
+                .collect::<Vec<_>>()
+        };
+
+        if !ongoing_work.is_empty() {
+            for id in ongoing_work.into_iter().map(|x| x.1) {
+                self.cancel_ongoing_work(id.clone());
+            }
+        }
+
+        // Return early if the server does not support pull diagnostic.
+        let identifier = match capabilities.diagnostic_provider.as_ref()? {
+            lsp::DiagnosticServerCapabilities::Options(cap) => cap.identifier.clone(),
+            lsp::DiagnosticServerCapabilities::RegistrationOptions(cap) => {
+                cap.diagnostic_options.identifier.clone()
+            }
+        };
+
+        let request_id = match self.next_request_id() {
+            jsonrpc::Id::Null => lsp::ProgressToken::Number(1),
+            jsonrpc::Id::Num(num) => lsp::ProgressToken::Number(num as i32),
+            jsonrpc::Id::Str(str) => lsp::ProgressToken::String(str),
+        };
+
+        let params = lsp::DocumentDiagnosticParams {
+            text_document: text_document.clone(),
+            identifier,
+            previous_result_id,
+            work_done_progress_params: lsp::WorkDoneProgressParams {
+                work_done_token: Some(request_id.clone()),
+            },
+            partial_result_params: lsp::PartialResultParams::default(),
+        };
+
+        self.ongoing_work
+            .lock()
+            .push((text_document, request_id.clone()));
+
+        Some((
+            self.call::<lsp::request::DocumentDiagnosticRequest>(params),
+            request_id,
+        ))
+    }
+
     pub fn text_document_document_highlight(
         &self,
         text_document: lsp::TextDocumentIdentifier,

helix-lsp/src/lib.rs

@@ -463,6 +463,7 @@ pub enum MethodCall {
     RegisterCapability(lsp::RegistrationParams),
     UnregisterCapability(lsp::UnregistrationParams),
     ShowDocument(lsp::ShowDocumentParams),
+    WorkspaceDiagnosticRefresh,
 }
 
 impl MethodCall {
@@ -494,6 +495,7 @@ impl MethodCall {
                 let params: lsp::ShowDocumentParams = params.parse()?;
                 Self::ShowDocument(params)
             }
+            lsp::request::WorkspaceDiagnosticRefresh::METHOD => Self::WorkspaceDiagnosticRefresh,
             _ => {
                 return Err(Error::Unhandled);
             }

helix-term/src/application.rs

@@ -1017,6 +1017,21 @@ impl Application {
                         let result = self.handle_show_document(params, offset_encoding);
                         Ok(json!(result))
                     }
+                    Ok(MethodCall::WorkspaceDiagnosticRefresh) => {
+                        for document in self.editor.documents() {
+                            let language_server = language_server!();
+                            if language_server.supports_feature(
+                                syntax::config::LanguageServerFeature::PullDiagnostics,
+                            ) && document.supports_language_server(language_server.id())
+                            {
+                                handlers::diagnostics::pull_diagnostics_for_document(
+                                    document,
+                                    language_server,
+                                );
+                            }
+                        }
+                        Ok(serde_json::Value::Null)
+                    }
                 };
 
                 let language_server = language_server!();

helix-term/src/handlers.rs

@@ -1,11 +1,13 @@
 use std::sync::Arc;
 
 use arc_swap::ArcSwap;
+use diagnostics::PullAllDocumentsDiagnosticHandler;
 use helix_event::AsyncHook;
 
 use crate::config::Config;
 use crate::events;
 use crate::handlers::auto_save::AutoSaveHandler;
+use crate::handlers::diagnostics::PullDiagnosticsHandler;
 use crate::handlers::signature_help::SignatureHelpHandler;
 
 pub use helix_view::handlers::Handlers;
@@ -14,7 +16,7 @@ use self::document_colors::DocumentColorsHandler;
 
 mod auto_save;
 pub mod completion;
-mod diagnostics;
+pub mod diagnostics;
 mod document_colors;
 mod signature_help;
 mod snippet;
@@ -26,12 +28,16 @@ pub fn setup(config: Arc<ArcSwap<Config>>) -> Handlers {
     let signature_hints = SignatureHelpHandler::new().spawn();
     let auto_save = AutoSaveHandler::new().spawn();
     let document_colors = DocumentColorsHandler::default().spawn();
+    let pull_diagnostics = PullDiagnosticsHandler::new().spawn();
+    let pull_all_documents_diagnostics = PullAllDocumentsDiagnosticHandler::new().spawn();
 
     let handlers = Handlers {
         completions: helix_view::handlers::completion::CompletionHandler::new(event_tx),
         signature_hints,
         auto_save,
         document_colors,
+        pull_diagnostics,
+        pull_all_documents_diagnostics,
     };
 
     helix_view::handlers::register_hooks(&handlers);