Add go-langserver

[edkolev]

This PR adds auto-detection for go-mode buffers utilizing https://github.com/sourcegraph/go-langserver.

[edkolev]

I'm getting these errors on save:

server-reply (id:2) ERROR Fri Aug 17 22:22:58 2018:
(:id 2 :error
     (:code -32601 :message "method not supported: textDocument/willSaveWaitUntil" :data nil)
     :jsonrpc "2.0")

Seems like eglot--server-capable is misbehaving when it receives multiple inputs. With go-langserver, the capabilities are (as returned by (eglot--capabilities (eglot--current-server-or-lose))):

(:textDocumentSync 2 :hoverProvider t :completionProvider (:triggerCharacters ["."]) :signatureHelpProvider (:triggerCharacters ["(" ","]) :definitionProvider t :typeDefinitionProvider t :referencesProvider t :documentSymbolProvider t :workspaceSymbolProvider t :implementationProvider t :documentFormattingProvider t :xworkspaceReferencesProvider t :xdefinitionProvider t :xworkspaceSymbolByProperties t)

Here's the return value of eglot--server-capable, which seems to me inconsistent:

;; this is how the function is called here https://github.com/joaotavora/eglot/blob/master/eglot.el#L1215
(eglot--server-capable :textDocumentSync :willSaveWaitUntil) ;; => 2

(eglot--server-capable :willSaveWaitUntil :textDocumentSync) ;; => nil
(eglot--server-capable :textDocumentSync) ;; => 2
(eglot--server-capable :willSaveWaitUntil) ;; => nil

[edkolev]

I just pushed another commit, intended to address the issue above.

[joaotavora]

@edkolev, although redesigning this problematic function isn't bad per se, you are breaking other use cases. I think, the correct fix is more like this

diff --git a/eglot.el b/eglot.el
index 88c6b45..63fbce2 100644
--- a/eglot.el
+++ b/eglot.el
@@ -728,12 +728,12 @@ under cursor."
                    feats)
     (cl-loop for caps = (eglot--capabilities (eglot--current-server-or-lose))
              then (cadr probe)
-             for feat in feats
+             for (feat . more) on feats
              for probe = (plist-member caps feat)
              if (not probe) do (cl-return nil)
              if (eq (cadr probe) :json-false) do (cl-return nil)
-             if (not (listp (cadr probe))) do (cl-return (cadr probe))
-             finally (cl-return (or probe t)))))
+             if (not (listp (cadr probe))) do (cl-return (if more nil (cadr probe)))
+             finally (cl-return (or (cadr probe) t)))))
 
 (defun eglot--range-region (range &optional markers)
   "Return region (BEG . END) that represents LSP RANGE.

Here is a unit test with some cases that the function must pass. Feel free to add more and discuss them here. If there are no objections I will push my version (and the unit test) sometime tomorrow.

(ert-deftest eglot-capabilities ()
  "Test `eglot--server-capable'"
  (cl-letf (((symbol-function 'eglot--capabilities)
             (lambda (_dummy)
               ;; test data lifted from Golangserver example at
               ;; https://github.com/joaotavora/eglot/pull/74
               (list :textDocumentSync 2 :hoverProvider t
                     :completionProvider '(:triggerCharacters ["."])
                     :signatureHelpProvider '(:triggerCharacters ["(" ","])
                     :definitionProvider t :typeDefinitionProvider t
                     :referencesProvider t :documentSymbolProvider t
                     :workspaceSymbolProvider t :implementationProvider t
                     :documentFormattingProvider t :xworkspaceReferencesProvider t
                     :xdefinitionProvider t :xworkspaceSymbolByProperties t)))
            ((symbol-function 'eglot--current-server-or-lose)
             (lambda () nil)))
    (should (eql 2 (eglot--server-capable :textDocumentSync)))
    (should (eglot--server-capable :completionProvider :triggerCharacters))
    (should (equal '(:triggerCharacters ["."]) (eglot--server-capable :completionProvider)))
    (should-not (eglot--server-capable :foobarbaz))
    (should-not (eglot--server-capable :textDocumentSync :foobarbaz))))

[joaotavora]

I will push my version (and the unit test) sometime tomorrow.

Actually, I changed my mind. Better push it now and amend it if you have any objections.

[edkolev]

No objections, plus I don't see the error in the logs anymore. I removed the commit which changed the eglot--server-capable function.

I'm getting however this lisp error with the go language server (I don't see it with the python lang server):

Debugger entered--Lisp error: (wrong-type-argument char-or-string-p nil)
  insert(nil)
  (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string))
  (unwind-protect (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))
  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer))))
  (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))))
  (let ((mode x6) (string x4)) (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer))))))
  (let* ((val (if (stringp markup) (list (string-trim markup) (intern "gfm-mode")) (list (plist-get markup :value) (intern (concat (plist-get markup :language) "-mode"))))) (x4 (car val)) (x5 (cdr val)) (x6 (car x5)) (x7 (cdr x5))) (let ((mode x6) (string x4)) (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (condition-case nil (progn (funcall mode)) (error nil)) (insert string) (font-lock-ensure) (buffer-string)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))))))
  eglot--format-markup(nil)
  mapconcat(eglot--format-markup (nil) "\n")
  (let ((heading (and range (let* ((val (eglot--range-region range)) (x24 (car val)) (x25 (cdr val))) (let ((end x25) (beg x24)) (concat (buffer-substring beg end) ": "))))) (body (mapconcat (function eglot--format-markup) (if (vectorp contents) contents (list contents)) "\n"))) (if (or heading (cl-plusp (length body))) (progn (concat heading body))))
  eglot--hover-info(nil nil)
  (and t (eglot--hover-info contents range))
  (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil))
  (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil)))
  (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil))))
  (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil)))))
  (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil))))))
  (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car --cl-keys--) '(:contents :range :allow-other-keys)) (setq --cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ':allow-other-keys --cl-rest--))) (setq --cl-keys-- nil)) (t (error "Keyword argument %s not one of (:contents :range)" (car --cl-keys--)))))) (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil)))))))
  (let* ((contents (car (cdr (plist-member --cl-rest-- ':contents)))) (range (car (cdr (plist-member --cl-rest-- ':range))))) (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car --cl-keys--) '(:contents :range :allow-other-keys)) (setq --cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ':allow-other-keys --cl-rest--))) (setq --cl-keys-- nil)) (t (error "Keyword argument %s not one of (:contents :range)" (car --cl-keys--)))))) (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil))))))))
  (closure ((jsonrpc-lambda-elem12) (sig-showing) (position-params :textDocument (:uri "file:///Users/edkolev/Exercism/go/isogram/isogram.go") :position (:line 6 :character 0)) (server . #<eglot-lsp-server eglot-lsp-server>) (buffer . #<buffer isogram.go>) eglot--managed-mode t) (&rest --cl-rest--) "\n\n(fn &key CONTENTS RANGE)" (let* ((contents (car (cdr (plist-member --cl-rest-- ':contents)))) (range (car (cdr (plist-member --cl-rest-- ':range))))) (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car --cl-keys--) '(:contents :range :allow-other-keys)) (setq --cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ':allow-other-keys --cl-rest--))) (setq --cl-keys-- nil)) (t (error "Keyword argument %s not one of (:contents :range)" (car --cl-keys--)))))) (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil)))))))))()
  apply((closure ((jsonrpc-lambda-elem12) (sig-showing) (position-params :textDocument (:uri "file:///Users/edkolev/Exercism/go/isogram/isogram.go") :position (:line 6 :character 0)) (server . #<eglot-lsp-server eglot-lsp-server>) (buffer . #<buffer isogram.go>) eglot--managed-mode t) (&rest --cl-rest--) "\n\n(fn &key CONTENTS RANGE)" (let* ((contents (car (cdr (plist-member --cl-rest-- ':contents)))) (range (car (cdr (plist-member --cl-rest-- ':range))))) (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car --cl-keys--) '(:contents :range :allow-other-keys)) (setq --cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ':allow-other-keys --cl-rest--))) (setq --cl-keys-- nil)) (t (error "Keyword argument %s not one of (:contents :range)" (car --cl-keys--)))))) (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil))))))))) nil)
  (closure ((sig-showing) (position-params :textDocument (:uri "file:///Users/edkolev/Exercism/go/isogram/isogram.go") :position (:line 6 :character 0)) (server . #<eglot-lsp-server eglot-lsp-server>) (buffer . #<buffer isogram.go>) eglot--managed-mode t) (jsonrpc-lambda-elem12) (apply (function (lambda (&rest --cl-rest--) "\n\n(fn &key CONTENTS RANGE)" (let* ((contents (car (cdr (plist-member --cl-rest-- ':contents)))) (range (car (cdr (plist-member --cl-rest-- ':range))))) (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car --cl-keys--) '(:contents :range :allow-other-keys)) (setq --cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ':allow-other-keys --cl-rest--))) (setq --cl-keys-- nil)) (t (error "Keyword argument %s not one of (:contents :range)" (car --cl-keys--)))))) (if sig-showing nil (if (or (get-buffer-window buffer) (ert-running-test)) (progn (save-current-buffer (set-buffer buffer) (let* ((info (and t (eglot--hover-info contents range)))) (if info (eldoc-message info) nil)))))))))) jsonrpc-lambda-elem12))(nil)
  jsonrpc-connection-receive(#<eglot-lsp-server eglot-lsp-server> (:id 13 :result nil :jsonrpc "2.0"))
  jsonrpc--process-filter(#<process EGLOT (isogram/go-mode)> "Content-Length: 39\015\n\015\n{\"id\":13,\"result\":null,\"jsonrpc\":\"2.0\"}")

[joaotavora]

I'm getting however this lisp error with the go language server (I don't see it with the python lang server):

This is likely a bug introduced by a later commit. It shouldn't be very hard to fix...

[joaotavora]

This is likely a bug introduced by a later commit.

Actually, it wasn't, but I fixed it anyway.

[joaotavora]

Pushed with a tweak to the commit message

[edkolev]

Great, thanks!

I've signed FSF's copyright assignment BTW.

[joaotavora]

Thanks. That's good to know.

…

On Sun, Aug 19, 2018, 05:20 Evgeni Kolev ***@***.***> wrote: Great, thanks! I've signed FSF's copyright assignment BTW. — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#74 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAXnw5VevJBoiFzn8nkU16x5z7MUZCGaks5uSOd9gaJpZM4V-uDS> .