hack.el

  (defun lsp--on-diagnostics (workspace params)
    "Callback for textDocument/publishDiagnostics.
interface PublishDiagnosticsParams {
    uri: string;
    diagnostics: Diagnostic[];
}
PARAMS contains the diagnostics data.
WORKSPACE is the workspace that contains the diagnostics."
    (let* ((file (lsp--uri-to-path (gethash "uri" params)))
           (diagnostics (seq-map #'lsp--make-diag (gethash "diagnostics" params)))
           (buffer (lsp--buffer-for-file file))
           (workspace-diagnostics (lsp--workspace-diagnostics workspace))
           (server (lsp--client-server-id (lsp--workspace-client workspace)))
           (filter (lambda (d)
                     (and (eq server 'ts-ls)
                          (< (lsp-diagnostic-severity d) 3)))))

      (if (seq-empty-p diagnostics)
          (remhash file workspace-diagnostics)
        (when (or lsp-report-if-no-buffer buffer)
          (puthash file (-filter filter diagnostics) workspace-diagnostics)))

      (run-hooks 'lsp-diagnostics-updated-hook)

      (when buffer
        (save-mark-and-excursion
          (with-current-buffer buffer
            (run-hooks 'lsp-after-diagnostics-hook))))))