Language client: added support for textDocument/diagnostic

src/source_language_protocol.cpp

@@ -277,7 +277,8 @@ LanguageProtocol::Capabilities LanguageProtocol::Client::initialize() {
     "formatting": { "dynamicRegistration": false },
     "rangeFormatting": { "dynamicRegistration": false },
     "rename": { "dynamicRegistration": false },
-    "publishDiagnostics": { "relatedInformation":true }
+    "publishDiagnostics": { "relatedInformation": true },
+    "diagnostic": { "dynamicRegistration": false, "relatedDocumentSupport": true }
   }
 },
 "initializationOptions": {
@@ -340,6 +341,8 @@ LanguageProtocol::Capabilities LanguageProtocol::Client::initialize() {
                   capabilities.workspace_folders = change_notifications->boolean_or(true); // Can be string as well
               }
             }
+            // Workaround since rust-analyzer erroneously uses both publish and pull diagnostic
+            capabilities.pull_diagnostic = language_id == "rust" ? false : boolean_or_object("diagnosticProvider");
           }
 
           // See https://clangd.llvm.org/extensions.html#utf-8-offsets for documentation on offsetEncoding
@@ -743,7 +746,10 @@ void Source::LanguageProtocolView::initialize() {
         update_status_state(this);
     }
 
+    if(capabilities.type_coverage)
       update_type_coverage();
+    if(capabilities.pull_diagnostic)
+      pull_diagnostic();
 
     initialized = true;
   };
@@ -765,6 +771,7 @@ Source::LanguageProtocolView::~LanguageProtocolView() {
   autocomplete_delayed_show_arguments_connection.disconnect();
   resolve_completion_item_connection.disconnect();
   update_type_coverage_connection.disconnect();
+  pull_diagnostic_connection.disconnect();
 
   if(initialize_thread.joinable())
     initialize_thread.join();
@@ -878,6 +885,7 @@ bool Source::LanguageProtocolView::save() {
 
   write_notification("textDocument/didSave");
 
+  if(capabilities.type_coverage)
     update_type_coverage();
 
   return true;
@@ -1545,6 +1553,12 @@ void Source::LanguageProtocolView::setup_signals() {
       write_did_change_notification({{"contentChanges", "[{" + to_string({"text", '"' + JSON::escape_string(get_buffer()->get_text().raw()) + '"'}) + "}]"}});
     });
   }
+
+  if(capabilities.pull_diagnostic) {
+    get_buffer()->signal_changed().connect([this]() {
+      pull_diagnostic();
+    });
+  }
 }
 
 void Source::LanguageProtocolView::setup_autocomplete() {
@@ -2526,7 +2540,6 @@ boost::optional<char> Source::LanguageProtocolView::get_named_parameter_symbol()
 }
 
 void Source::LanguageProtocolView::update_type_coverage() {
-  if(capabilities.type_coverage) {
   write_request("textDocument/typeCoverage", {}, [this](JSON &&result, bool error) {
     if(error) {
       if(update_type_coverage_retries > 0) { // Retry typeCoverage request, since these requests can fail while waiting for language server to start
@@ -2565,5 +2578,26 @@ void Source::LanguageProtocolView::update_type_coverage() {
       update_diagnostics(last_diagnostics);
     });
   });
+}
+
+void Source::LanguageProtocolView::pull_diagnostic() {
+  pull_diagnostic_connection.disconnect();
+  pull_diagnostic_connection = Glib::signal_timeout().connect(
+      [this]() {
+        write_request("textDocument/diagnostic", {}, [this](JSON &&result, bool error) {
+          if(!error) {
+            std::vector<std::shared_ptr<LanguageProtocol::Diagnostic>> diagnostics;
+            for(auto &child : result.array_or_empty("items")) {
+              try {
+                diagnostics.emplace_back(std::make_shared<LanguageProtocol::Diagnostic>(std::move(child)));
               }
+              catch(...) {
+              }
+            }
+            update_diagnostics_async(std::move(diagnostics));
+          }
+        });
+        return false;
+      },
+      1000);
 }

src/source_language_protocol.hpp

@@ -140,6 +140,7 @@ namespace LanguageProtocol {
     bool code_action_resolve = false;
     bool execute_command = false;
     bool type_coverage = false;
+    bool pull_diagnostic = false;
     bool use_line_index = false;
   };
 
@@ -307,5 +308,8 @@ namespace Source {
     size_t num_warnings = 0, num_errors = 0, num_fix_its = 0;
     void update_type_coverage();
     std::atomic<int> update_type_coverage_retries = {60};
+
+    sigc::connection pull_diagnostic_connection;
+    void pull_diagnostic();
   };
 } // namespace Source