#3467 lsp: add setting to show log output as debug log

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

CHANGELOG.md

@@ -16,6 +16,24 @@
   was called synchronously, causing a SIGSEGV in QtWidgets; the UI update is now
   deferred via `QTimer::singleShot` so it runs after the current event is fully
   processed (for [#3578](https://github.com/pbek/QOwnNotes/issues/3578))
+- Added a **Show all LSP server log output in debug log** checkbox to the
+  **Markdown language server** section in the **Editor** settings; when
+  enabled, every line written to the LSP server's stderr is forwarded to
+  the Qt debug log so the full server output is visible (e.g. via
+  `QT_LOGGING_RULES="*.debug=true"`); the checkbox is disabled when the
+  LSP is not enabled (for [#3467](https://github.com/pbek/QOwnNotes/issues/3467))
+  - All Markdown LSP server stderr output is then forwarded to the debug log
+    (via `qDebug`) so the full server log is visible when running QOwnNotes
+    with debug output enabled; previously only lines containing `ERR`/`ERROR`
+    were forwarded
+  - Added debug logging when `textDocument/publishDiagnostics` notifications
+    are received from the Markdown LSP server and when they are applied to the
+    note text edit, to help diagnose why error markers may not appear; note that
+    `marksman` (the default LSP server) does not publish diagnostics — it
+    focuses on cross-reference and wiki-link completion only; to get real-time
+    wave-underline error markers in the note editor, configure a linting LSP
+    such as `rumdl` (command: `rumdl`, argument: `server`) which provides 71
+    Markdown lint rules and publishes `textDocument/publishDiagnostics`
 
 ## 26.4.22
 

src/services/markdownlspclient.cpp

@@ -28,6 +28,8 @@ void MarkdownLspClient::setServerCommand(const QString &command, const QStringLi
     _arguments = arguments;
 }
 
+void MarkdownLspClient::setVerboseLogging(bool enabled) { _verboseLogging = enabled; }
+
 bool MarkdownLspClient::start() {
     if (_command.isEmpty()) {
         emit errorMessage(tr("Markdown LSP server command is empty"));
@@ -427,6 +429,10 @@ void MarkdownLspClient::onReadyReadStandardError() {
             if (trimmed.isEmpty()) {
                 continue;
             }
+            // Log all stderr output as debug if verbose logging is enabled
+            if (_verboseLogging) {
+                qDebug() << "Markdown LSP server:" << trimmed;
+            }
             if (errorPattern.match(trimmed).hasMatch()) {
                 emit errorMessage(trimmed);
             }
@@ -625,6 +631,7 @@ void MarkdownLspClient::handleNotification(const QJsonObject &object) {
         diagnostics.push_back(diagnostic);
     }
 
+    qDebug() << "Markdown LSP diagnostics received for" << uri << "- count:" << diagnostics.size();
     emit diagnosticsReceived(uri, diagnostics);
 }
 

src/services/markdownlspclient.h

@@ -45,6 +45,7 @@ class MarkdownLspClient : public QObject {
     ~MarkdownLspClient() override;
 
     void setServerCommand(const QString &command, const QStringList &arguments);
+    void setVerboseLogging(bool enabled);
     bool start();
     void shutdown();
     bool isRunning() const;
@@ -99,6 +100,7 @@ class MarkdownLspClient : public QObject {
     QByteArray _readBuffer;
     QString _command;
     QStringList _arguments;
+    bool _verboseLogging = false;
     int _nextRequestId = 1;
     int _initializeRequestId = -1;
     bool _initialized = false;

src/widgets/qownnotesmarkdowntextedit.cpp

@@ -3439,6 +3439,8 @@ void QOwnNotesMarkdownTextEdit::applyMarkdownLspSettings() {
             .toString();
     const QStringList arguments =
         settings.value(QStringLiteral("Editor/markdownLspArguments")).toStringList();
+    const bool verboseLogging =
+        settings.value(QStringLiteral("Editor/markdownLspVerboseLogging"), false).toBool();
 
     if (!enabled) {
         _markdownLspEnabled = false;
@@ -3473,6 +3475,7 @@ void QOwnNotesMarkdownTextEdit::applyMarkdownLspSettings() {
     }
 
     _markdownLspClient->setServerCommand(command, arguments);
+    _markdownLspClient->setVerboseLogging(verboseLogging);
     if (_markdownLspClient->start()) {
         const QString rootPath = NoteFolder::currentLocalPath();
         _markdownLspClient->initialize(rootPath, QStringLiteral("QOwnNotes"),
@@ -3598,9 +3601,12 @@ void QOwnNotesMarkdownTextEdit::showMarkdownLspCompletions(int requestId,
 void QOwnNotesMarkdownTextEdit::showMarkdownLspDiagnostics(
     const QString &uri, const QVector<MarkdownLspClient::Diagnostic> &diagnostics) {
     if (uri != _markdownLspUri) {
+        qDebug() << "Markdown LSP: ignoring diagnostics for" << uri
+                 << "(current:" << _markdownLspUri << ")";
         return;
     }
 
+    qDebug() << "Markdown LSP: applying" << diagnostics.size() << "diagnostics for" << uri;
     _markdownLspDiagnostics = diagnostics;
     _markdownLspDiagnosticsSelections.clear();
     for (const MarkdownLspClient::Diagnostic &diagnostic : diagnostics) {

src/widgets/settings/editorsettingswidget.cpp

@@ -91,6 +91,8 @@ void EditorSettingsWidget::readSettings() {
         settings.value(QStringLiteral("Editor/markdownLspArguments"))
             .toStringList()
             .join(QLatin1Char(' ')));
+    ui->markdownLspVerboseLoggingCheckBox->setChecked(
+        settings.value(QStringLiteral("Editor/markdownLspVerboseLogging"), false).toBool());
     // Initialize dependent widget state for LSP fields
     on_markdownLspEnabledCheckBox_toggled(ui->markdownLspEnabledCheckBox->isChecked());
     ui->cursorWidthSpinBox->setValue(settings.value(QStringLiteral("cursorWidth"), 1).toInt());
@@ -147,6 +149,8 @@ void EditorSettingsWidget::storeSettings() {
 #else
                           QRegularExpression(QStringLiteral("\\s+")), Qt::SkipEmptyParts));
 #endif
+    settings.setValue(QStringLiteral("Editor/markdownLspVerboseLogging"),
+                      ui->markdownLspVerboseLoggingCheckBox->isChecked());
     settings.setValue(QStringLiteral("cursorWidth"), ui->cursorWidthSpinBox->value());
     settings.setValue(QStringLiteral("insertTimeFormat"), ui->timeFormatLineEdit->text());
 }
@@ -173,6 +177,7 @@ void EditorSettingsWidget::on_markdownLspEnabledCheckBox_toggled(bool checked) {
     ui->markdownLspArgumentsLineEdit->setEnabled(checked);
     ui->markdownLspCommandLabel->setEnabled(checked);
     ui->markdownLspArgumentsLabel->setEnabled(checked);
+    ui->markdownLspVerboseLoggingCheckBox->setEnabled(checked);
 }
 
 /**

src/widgets/settings/editorsettingswidget.ui

@@ -302,19 +302,29 @@
         </property>
        </widget>
       </item>
-      <item row="2" column="1">
-       <widget class="QLineEdit" name="markdownLspArgumentsLineEdit">
-        <property name="toolTip">
-         <string>Optional arguments separated by spaces.</string>
-        </property>
-        <property name="placeholderText">
-         <string>Optional arguments</string>
-        </property>
-        <property name="clearButtonEnabled">
-         <bool>true</bool>
-        </property>
-       </widget>
-      </item>
+       <item row="2" column="1">
+        <widget class="QLineEdit" name="markdownLspArgumentsLineEdit">
+         <property name="toolTip">
+          <string>Optional arguments separated by spaces.</string>
+         </property>
+         <property name="placeholderText">
+          <string>Optional arguments</string>
+         </property>
+         <property name="clearButtonEnabled">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+       <item row="3" column="0" colspan="2">
+        <widget class="QCheckBox" name="markdownLspVerboseLoggingCheckBox">
+         <property name="toolTip">
+          <string>Log all LSP server output (stderr) to the debug log. Useful for troubleshooting LSP server issues.</string>
+         </property>
+         <property name="text">
+          <string>Show all LSP server log output in debug log</string>
+         </property>
+        </widget>
+       </item>
      </layout>
     </widget>
    </item>