Workaround new Eldoc on Emacs 27 (#3810)

* Revert "Revert "Move to new eldoc (#3275)""

This reverts commit 056865f.

* Correctly declare lsp-eldoc-hook as an obsolete variable

* Workaround new Eldoc on Emacs 27

Fixes #3295

* Just override eldoc strategy on older Emacs for simplicity

Add remove reminder comment.

* New eldoc: try to pass CI

Author: daanturo

.github/workflows/test.yml

@@ -14,8 +14,6 @@ jobs:
             matrix:
                 os: [ubuntu-latest, macos-latest]
                 emacs-version:
-                    - 26.1
-                    - 26.2
                     - 26.3
                     - 27.1
                     - 27.2
@@ -72,8 +70,6 @@ jobs:
             fail-fast: false
             matrix:
                 emacs-version:
-                    - 26.1
-                    - 26.2
                     - 26.3
                     - 27.1
                     - 27.2

CHANGELOG.org

@@ -1,5 +1,6 @@
 * Changelog
 ** Unreleased 8.0.1
+  * Drop support for emacs 26.1 and 26.2
   * Added support for ~textDocument/linkedEditingRange~ via
     ~lsp-iedit-linked-ranges~ and ~lsp-evil-multiedit-ranges~ (see [[https://github.com/emacs-lsp/lsp-mode/pull/3166][#3166]])
   * Add [[https://github.com/graphql/graphiql/tree/main/packages/graphql-language-service-cli#readme][GraphQL Language Server]] for autocomplete graphql query

lsp-mode.el

@@ -4,7 +4,7 @@
 
 ;; Author: Vibhav Pant, Fangrui Song, Ivan Yonchovski
 ;; Keywords: languages
-;; Package-Requires: ((emacs "26.1") (dash "2.18.0") (f "0.20.0") (ht "2.3") (spinner "1.7.3") (markdown-mode "2.3") (lv "0"))
+;; Package-Requires: ((emacs "26.3") (dash "2.18.0") (f "0.20.0") (ht "2.3") (spinner "1.7.3") (markdown-mode "2.3") (lv "0") (eldoc "1.11"))
 ;; Version: 8.0.1
 
 ;; URL: https://github.com/emacs-lsp/lsp-mode
@@ -607,10 +607,7 @@ The hook will receive two parameters list of added and removed folders."
   :type 'hook
   :group 'lsp-mode)
 
-(defcustom lsp-eldoc-hook '(lsp-hover)
-  "Hooks to run for eldoc."
-  :type 'hook
-  :group 'lsp-mode)
+(define-obsolete-variable-alias 'lsp-eldoc-hook 'eldoc-documentation-functions "lsp-mode 8.0.1")
 
 (defcustom lsp-before-apply-edits-hook nil
   "Hooks to run before applying edits."
@@ -1190,17 +1187,6 @@ See #2049"
   "Display lsp error message with FORMAT with ARGS."
   (lsp--message "%s :: %s" (propertize "LSP" 'face 'error) (apply #'format format args)))
 
-(defun lsp--eldoc-message (&optional msg)
-  "Show MSG in eldoc."
-  (setq lsp--eldoc-saved-message msg)
-  (run-with-idle-timer 0 nil (lambda ()
-                               ;; XXX: new eldoc in Emacs 28
-                               ;; recommends running the hook variable
-                               ;; `eldoc-documentation-functions'
-                               ;; instead of using eldoc-message
-                               (with-no-warnings
-                                 (eldoc-message msg)))))
-
 (defun lsp-log (format &rest args)
   "Log message to the ’*lsp-log*’ buffer.
 
@@ -3972,13 +3958,23 @@ yet."
   (lsp-disconnect)
   (lsp))
 
+;; TODO remove those eldoc workarounds when dropping support for Emacs 27
+;; https://github.com/emacs-lsp/lsp-mode/issues/3295#issuecomment-1308994099
+(defvar eldoc-documentation-default) ; CI
+(when (< emacs-major-version 28)
+  (unless (boundp 'eldoc-documentation-functions)
+    (load "eldoc"))
+  (when (memq (default-value 'eldoc-documentation-function) '(nil ignore))
+    ;; actually `eldoc-documentation-strategy', but CI was failing
+    (setq-default eldoc-documentation-function 'eldoc-documentation-default)))
+
 (define-minor-mode lsp-managed-mode
   "Mode for source buffers managed by lsp-mode."
   :lighter nil
   (cond
    (lsp-managed-mode
     (when (lsp-feature? "textDocument/hover")
-      (add-function :before-until (local 'eldoc-documentation-function) #'lsp-eldoc-function)
+      (add-hook 'eldoc-documentation-functions #'lsp-eldoc-function nil t)
       (eldoc-mode 1))
 
     (add-hook 'after-change-functions #'lsp-on-change nil t)
@@ -4013,8 +4009,8 @@ yet."
              (lsp--on-idle buffer)))))))
    (t
     (lsp-unconfig-buffer)
-    (remove-function (local 'eldoc-documentation-function) #'lsp-eldoc-function)
 
+    (remove-hook 'eldoc-documentation-functions #'lsp-eldoc-function t)
     (remove-hook 'post-command-hook #'lsp--post-command t)
     (remove-hook 'after-change-functions #'lsp-on-change t)
     (remove-hook 'after-revert-hook #'lsp-on-revert t)
@@ -5078,10 +5074,32 @@ If EXCLUDE-DECLARATION is non-nil, request the server to include declarations."
    (->> lsp--cur-workspace lsp--workspace-client lsp--client-response-handlers (remhash id))
    (lsp-notify "$/cancelRequest" `(:id ,id))))
 
-(defun lsp-eldoc-function ()
-  "`lsp-mode' eldoc function."
-  (run-hooks 'lsp-eldoc-hook)
-  eldoc-last-message)
+(defvar-local lsp--hover-saved-bounds nil)
+
+(defun lsp-eldoc-function (cb &rest _ignored)
+  "`lsp-mode' eldoc function to display hover info (based on `textDocument/hover')."
+  (if (and lsp--hover-saved-bounds
+           (lsp--point-in-bounds-p lsp--hover-saved-bounds))
+      lsp--eldoc-saved-message
+    (setq lsp--hover-saved-bounds nil
+          lsp--eldoc-saved-message nil)
+    (if (looking-at "[[:space:]\n]")
+        (setq lsp--eldoc-saved-message nil) ; And returns nil.
+      (when (and lsp-eldoc-enable-hover (lsp--capability :hoverProvider))
+        (lsp-request-async
+         "textDocument/hover"
+         (lsp--text-document-position-params)
+         (-lambda ((hover &as &Hover? :range? :contents))
+           (setq lsp--hover-saved-bounds (when range?
+                                           (lsp--range-to-region range?)))
+           (funcall cb (setq lsp--eldoc-saved-message
+                             (when contents
+                               (lsp--render-on-hover-content
+                                contents
+                                lsp-eldoc-render-all)))))
+         :error-handler #'ignore
+         :mode 'tick
+         :cancel-token :eldoc-hover)))))
 
 (defun lsp--point-on-highlight? ()
   (-some? (lambda (overlay)
@@ -5675,36 +5693,6 @@ It will show up only if current point has signature help."
      :mode 'unchanged
      :cancel-token :document-color-token)))
 
-
-;; hover
-
-(defvar-local lsp--hover-saved-bounds nil)
-
-(defun lsp-hover ()
-  "Display hover info (based on `textDocument/signatureHelp')."
-  (if (and lsp--hover-saved-bounds
-           (lsp--point-in-bounds-p lsp--hover-saved-bounds))
-      (lsp--eldoc-message lsp--eldoc-saved-message)
-    (setq lsp--hover-saved-bounds nil
-          lsp--eldoc-saved-message nil)
-    (if (looking-at "[[:space:]\n]")
-        (lsp--eldoc-message nil)
-      (when (and lsp-eldoc-enable-hover (lsp-feature? "textDocument/hover"))
-        (lsp-request-async
-         "textDocument/hover"
-         (lsp--text-document-position-params)
-         (-lambda ((hover &as &Hover? :range? :contents))
-           (when hover
-             (when range?
-               (setq lsp--hover-saved-bounds (lsp--range-to-region range?)))
-             (lsp--eldoc-message (and contents
-                                      (lsp--render-on-hover-content
-                                       contents
-                                       lsp-eldoc-render-all)))))
-         :error-handler #'ignore
-         :mode 'tick
-         :cancel-token :eldoc-hover)))))
-
 
 
 (defun lsp--action-trigger-parameter-hints (_command)