message: Use typeguard in diagnosticsProvider as wel
diff: @@ -272,7 +272,7 @@ class DiagnosticsProvider extends AbstractSupport {
  private _mapQuickFixesAsDiagnosticsInFile(quickFixes: protocol.QuickFix[]): { diagnostic: vscode.Diagnostic, fileName: string }[] {
  return quickFixes
  .map(quickFix => this._asDiagnosticInFileIfAny(quickFix))
  - .filter(diagnosticInFile => diagnosticInFile !== undefined) as { diagnostic: vscode.Diagnostic, fileName: string }[];
  + .filter((diagnosticInFile): diagnosticInFile is NonNullable<typeof diagnosticInFile> => diagnosticInFile !== undefined);
  }
  private async _validateEntireWorkspace() {
  