#+TITLE: Language - JavaScript - LSP
#+AUTHOR: Juan Placencia

* Package

Define JavaScript language LSP Integration package.

#+BEGIN_SRC emacs-lisp
  (use-package emacs
    :after (uno-lang-js uno-dev-lsp projectile)
    :config
    (provide 'uno-lang-js-lsp))
#+END_SRC

* LSP Integration

#+BEGIN_SRC emacs-lisp
  (use-package emacs
    :after uno-lang-js-lsp
    :init
    (require 'seq)
    (defun uno/lang/js/lsp/add-to-local (name file)
      "Add NAME dependency from FILE to local instance."
      (when (uno/lang/js/lsp/local-provider file)
        (lsp-dependency name `(:local ,file))
        t))
    (defun uno/lang/js/lsp/check ()
      "Set up support with local SDK instance."
      (when (uno/lang/js/lsp/local-provider)
        (require 'lsp-javascript)
        (make-local-variable 'lsp-enabled-clients)
        (plist-put lsp-deps-providers
                   :local '(:path uno/lang/js/lsp/local-provider))
        (setq-local lsp-auto-guess-root t)
        (run-hooks 'uno-lang-js-lsp-hook)))
    (defun uno/lang/js/lsp/local-provider (&optional path)
      "Provide path for local SDK instance relative to PATH."
      (seq-reduce
       (lambda (current sdk)
         (if current
             current
           (let ((-path (concat (projectile-project-root) sdk path)))
             (if (file-exists-p -path) -path nil))))
       '(".yarn/sdks/" "node_modules/")
       nil))
    (defun uno/lang/js/lsp/local-provider-type (&optional path)
      "Check SDK instance type relative to PATH."
      (let ((-path (uno/lang/js/lsp/local-provider path)))
        (cond
         (string-match-p ".yarn/sdks/" -path) "yarn")
         (string-match-p "node_modules/" -path) "npm")))
#+END_SRC

** ESLint Integration

#+BEGIN_SRC emacs-lisp
  (use-package emacs
    :after (uno-lang-js-lsp flycheck)
    :hook
    (uno-lang-js-lsp . uno/lang/js/eslint/add)
    :init
    (defun uno/lang/js/eslint/add ()
      "Add support for ESLint."
      (when (uno/lang/js/lsp/local-provider "eslint/bin/eslint.js")
        (let ((-eslint-full
               (uno/lang/js/lsp/local-provider "eslint/bin/eslint.js"))
              (-node-path (uno/lang/js/lsp/local-provider)))
          (setq-local
           flycheck-javascript-eslint-executable -eslint-full
           lsp-eslint-node-path -node-path
           lsp-eslint-package-manager (uno/lang/js/lsp/local-provider-type)))
        (push 'eslint lsp-enabled-clients)))
    (uno/add-useless-buffer "\\*eslint\\*")
    (uno/add-useless-buffer "\\*eslint::.*\\*"))
#+END_SRC