LSP is reinstalled even when UPDATE? is nil

[EmilyGraceSeville7cf]

Thank you for the bug report

• I am using the latest version of lsp-mode related packages.
• I checked FAQ and Troubleshooting sections
• You may also try reproduce the issue using clean environment using the following command: M-x lsp-start-plain

Bug description

When I open any file Emacs shows message for csharp-ls LSP even I told it not to reinstall ((lsp-install-server nil server)) LSP:

Steps to reproduce

1. Open any file with my ~/.emacs config

Expected behavior

No reinstallation occured when UPDATE? is nil.

Which Language Server did you use?

csharp-ls

OS

Linux

Error callstack

No response

Anything else?

~/.emacs:

;;; .emacs --- My custom .emacs config.
;;; Commentary:
;;; Installs different packages for code linting and formatting to enable user feel Emacs like an IDE.
;;; Code:

(require 'package)
(require 'lsp-mode)

(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)

(defvar emacs-themes '(soft-stone-theme) "Themes installed as packages.")
(defvar emacs-linters '(flycheck json-mode yaml-mode markdown-mode) "Code linters installed as packages.")
(defvar emacs-language-servers '(lsp-mode lsp-pyright lsp-java) "Language servers installed as packages.")
(defvar emacs-formatters '(format-all) "Code formatters installed as packages.")
(defvar emacs-other '(company) "Other packages installed as packages.")

(defvar emacs-packages (append emacs-themes emacs-linters emacs-language-servers emacs-formatters emacs-other))
(dolist (package emacs-packages)
  (package-install package))

(setq emacs-language-servers '(bash-ls csharp-ls))
(dolist (server emacs-language-servers)
  (lsp-install-server nil server)) ; Reinstallation occures even when UPDATE? is nil

(defvar bookmark-save-flag 1)
(load-theme 'soft-stone t)
(setq-default tab-width 4)
(setq-default display-line-numbers 'relative)
(add-hook 'prog-mode-hook #'flycheck-mode)
(add-hook 'prog-mode-hook #'company-mode)
(add-hook 'prog-mode-hook #'format-all-mode)
(defvar emacs-hooks '(shell-mode-hook python-mode-hook java-mode-hook csharp-mode-hook c++-mode-hook))
(dolist (hook emacs-hooks)
  (add-hook hook #'lsp))
(defvar format-all-formatters '(("JSON" prettier)
				("YAML" prettier)
				("Shell" shfmt)
				("Python" black)
				("Java" clang-format)
				("C#" clang-format)))

(custom-set-variables
 ;; custom-set-variables was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(package-selected-packages
   '(lsp-java csharp-mode company lsp-pyright lsp-mode format-all yaml-mode json-mode markdown-mode flycheck soft-stone-theme)))
(custom-set-faces
 ;; custom-set-faces was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 )

(provide '.emacs)
;;; .emacs ends here

lsp-log:

Command "/usr/local/bin/bash-language-server start" is present on the path.

[yyoncho]

Use lsp-ensure-server instead of calling install with update nil.

[EmilyGraceSeville7cf]

@yyoncho, is it a bug with update == nil? Why there is an update parameter anyway? 🤔

[EmilyGraceSeville7cf]

Ensure server SERVER-ID

Doesn't describe what this function returns. Please fix docs.

[EmilyGraceSeville7cf]

Working code:

(dolist (server emacs-language-servers)                                                                                                        
  (lsp-ensure-server server))

Not working code (but documentation doesn't describe how to use this function clearly):

(dolist (server emacs-language-servers)                                                                                                        
   (if (not (lsp-ensure-server server))                                                                                                         
      (lsp-install-server nil server)))