[Fix #3733] Remove support for sideloading

Sideloading was removed in nREPL 1.3, as it was not particularly useful
and never gain any meaningful adoption in the broader Clojure community.

Author: bbatsov

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 - Bump the injected nREPL version to 1.3.
 - Bump the injected `cider-nrepl` to [0.49.3](https://github.com/clojure-emacs/cider-nrepl/blob/master/CHANGELOG.md#0493-2024-08-13).
+- [#3733](https://github.com/clojure-emacs/cider/issues/3733): Remove support for sideloading. (this experimental feature was removed from nREPL 1.3)
 
 ### Bugs fixed
 

ROADMAP.md

@@ -49,7 +49,6 @@ There's a bit of info on the subject [here](https://github.com/clojure-emacs/cid
 
 ## Implement new nREPL features
 
-* sideloading (there's some experimental support for this)
 * dynamic middleware loading
 * ~~completion~~
 * ~~lookup~~

cider-eval.el

@@ -204,190 +204,6 @@ When invoked with a prefix ARG the command doesn't prompt for confirmation."
     (save-excursion
       (quit-window nil error-win))))
 
-
-;;; Sideloader
-;;
-;; nREPL includes sideloader middleware which provides a Java classloader that
-;; is able to dynamically load classes and resources at runtime by interacting
-;; with the nREPL client (as opposed to using the classpath of the JVM hosting
-;; nREPL server).
-;;
-;; This performs a similar functionality as the load-file
-;; operation, where we can load Clojure namespaces (as source files) or Java
-;; classes (as bytecode) by simply requiring or importing them.
-;;
-;; See https://nrepl.org/nrepl/design/middleware.html#sideloading
-
-(defcustom cider-sideloader-path nil
-  "List of directories and jar files to scan for sideloader resources.
-When not set the cider-nrepl jar will be added automatically when upgrading
-an nREPL connection."
-  :type 'list
-  :group 'cider
-  :package-version '(cider . "1.2.0"))
-
-(defcustom cider-dynload-cider-nrepl-version nil
-  "Version of the cider-nrepl jar used for dynamically upgrading a connection.
-Defaults to `cider-required-middleware-version'."
-  :type 'string
-  :group 'cider
-  :package-version '(cider . "1.2.0"))
-
-(defun cider-read-bytes (path)
-  "Read binary data from PATH.
-Return the binary data as unibyte string."
-  ;; based on f-read-bytes
-  (with-temp-buffer
-    (set-buffer-multibyte nil)
-    (setq buffer-file-coding-system 'binary)
-    (insert-file-contents-literally path nil)
-    (buffer-substring-no-properties (point-min) (point-max))))
-
-(defun cider-retrieve-resource (dirs name)
-  "Find a resource NAME in a list DIRS of directories or jar files.
-Similar to a classpath lookup.  Returns the file contents as a string."
-  (seq-some
-   (lambda (path)
-     (cond
-      ((file-directory-p path)
-       (let ((expanded (expand-file-name name path)))
-         (when (file-exists-p expanded)
-           (cider-read-bytes expanded))))
-      ((and (file-exists-p path) (string-suffix-p ".jar" path))
-       (cider-jar-retrieve-resource path name))))
-   dirs))
-
-(defun cider-provide-file (file)
-  "Provide FILE in a format suitable for sideloading."
-  (let ((contents (cider-retrieve-resource cider-sideloader-path file)))
-    (if contents
-        (base64-encode-string contents 'no-line-breaks)
-      ;; if we can't find the file we should return an empty string
-      (base64-encode-string ""))))
-
-(defun cider-sideloader-lookup-handler ()
-  "Make a sideloader-lookup handler."
-  (lambda (response)
-    (nrepl-dbind-response response (id status type name)
-      (if status
-          (when (member "sideloader-lookup" status)
-            (cider-request:sideloader-provide id type name))))))
-
-(defun cider-add-middleware-handler (continue)
-  "Make a add-middleware handler.
-CONTINUE is an optional continuation function."
-  (lambda (response)
-    (nrepl-dbind-response response (status unresolved-middleware) ;; id middleware
-      (when unresolved-middleware
-        (seq-do
-         (lambda (mw)
-           (cider-repl-emit-interactive-stderr
-            (concat "WARNING: middleware " mw " was not found or failed to load.\n")))
-         unresolved-middleware))
-      (when (and status (member "done" status) continue)
-        (funcall continue)))))
-
-(defun cider-request:sideloader-start (&optional connection tooling)
-  "Perform the nREPL \"sideloader-start\" op.
-If CONNECTION is nil, use `cider-current-repl'.
-If TOOLING is truthy then the operation is performed over the tooling
-session, rather than the regular session."
-  (cider-ensure-op-supported "sideloader-start")
-  (cider-nrepl-send-request `("op" "sideloader-start")
-                            (cider-sideloader-lookup-handler)
-                            connection
-                            tooling))
-
-(defun cider-request:sideloader-provide (id type file &optional connection)
-  "Perform the nREPL \"sideloader-provide\" op for ID, TYPE and FILE.
-If CONNECTION is nil, use `cider-current-repl'."
-  (cider-nrepl-send-request `("id" ,id
-                              "op" "sideloader-provide"
-                              "type" ,type
-                              "name" ,file
-                              "content" ,(cider-provide-file file))
-                            (cider-sideloader-lookup-handler)
-                            connection))
-
-(defun cider-sideloader-start (&optional connection)
-  "Start nREPL's sideloader.
-If CONNECTION is nil, use `cider-current-repl'."
-  (interactive)
-  (message "Starting nREPL's sideloader")
-  (cider-request:sideloader-start connection)
-  (cider-request:sideloader-start connection 'tooling))
-
-(defvar cider-nrepl-middlewares
-  '("cider.nrepl/wrap-apropos"
-    "cider.nrepl/wrap-classpath"
-    "cider.nrepl/wrap-clojuredocs"
-    "cider.nrepl/wrap-complete"
-    "cider.nrepl/wrap-content-type"
-    "cider.nrepl/wrap-debug"
-    "cider.nrepl/wrap-enlighten"
-    "cider.nrepl/wrap-format"
-    "cider.nrepl/wrap-info"
-    "cider.nrepl/wrap-inspect"
-    "cider.nrepl/wrap-log"
-    "cider.nrepl/wrap-macroexpand"
-    "cider.nrepl/wrap-ns"
-    "cider.nrepl/wrap-out"
-    "cider.nrepl/wrap-slurp"
-    "cider.nrepl/wrap-profile"
-    "cider.nrepl/wrap-refresh"
-    "cider.nrepl/wrap-resource"
-    "cider.nrepl/wrap-spec"
-    "cider.nrepl/wrap-stacktrace"
-    "cider.nrepl/wrap-test"
-    "cider.nrepl/wrap-trace"
-    "cider.nrepl/wrap-tracker"
-    "cider.nrepl/wrap-undef"
-    "cider.nrepl/wrap-version"
-    "cider.nrepl/wrap-xref"))
-
-(defun cider-request:add-middleware (middlewares
-                                     &optional connection tooling continue)
-  "Use the nREPL dynamic loader to add MIDDLEWARES to the nREPL session.
-
-- If CONNECTION is nil, use `cider-current-repl'.
-- If TOOLING it truthy, use the tooling session instead of the main session.
-- CONTINUE is an optional continuation function, which will be called when the
-add-middleware op has finished successfully."
-  (cider-nrepl-send-request `("op" "add-middleware"
-                              "middleware" ,middlewares)
-                            (cider-add-middleware-handler continue)
-                            connection
-                            tooling))
-
-(defun cider-add-cider-nrepl-middlewares (&optional connection)
-  "Use dynamic loading to add the cider-nrepl middlewares to nREPL.
-If CONNECTION is nil, use `cider-current-repl'."
-  (cider-request:add-middleware
-   cider-nrepl-middlewares connection nil
-   (lambda ()
-     ;; When the main session is done adding middleware, then do the tooling
-     ;; session. At this point all the namespaces have been sideloaded so this
-     ;; is faster, we don't want these to race to sideload resources.
-     (cider-request:add-middleware
-      cider-nrepl-middlewares connection 'tooling
-      (lambda ()
-        ;; Ask nREPL again what its capabilities are, so we know which new
-        ;; operations are supported.
-        (nrepl--init-capabilities (or connection (cider-current-repl))))))))
-
-(defvar cider-required-middleware-version)
-(defun cider-upgrade-nrepl-connection (&optional connection)
-  "Sideload cider-nrepl middleware.
-If CONNECTION is nil, use `cider-current-repl'."
-  (interactive)
-  (when (not cider-sideloader-path)
-    (setq cider-sideloader-path (list (cider-jar-find-or-fetch
-                                       "cider" "cider-nrepl"
-                                       (or cider-dynload-cider-nrepl-version
-                                           cider-required-middleware-version)))))
-  (cider-sideloader-start connection)
-  (cider-add-cider-nrepl-middlewares connection))
-
 
 ;;; Dealing with compilation (evaluation) errors and warnings
 (defun cider-find-property (property &optional backward)

cider-repl.el

@@ -1692,7 +1692,6 @@ constructs."
 (declare-function cider-version "cider")
 (declare-function cider-test-run-loaded-tests "cider-test")
 (declare-function cider-test-run-project-tests "cider-test")
-(declare-function cider-sideloader-start "cider-eval")
 (cider-repl-add-shortcut "clear-output" #'cider-repl-clear-output)
 (cider-repl-add-shortcut "clear" #'cider-repl-clear-buffer)
 (cider-repl-add-shortcut "clear-banners" #'cider-repl-clear-banners)
@@ -1706,7 +1705,6 @@ constructs."
 (cider-repl-add-shortcut "classpath" #'cider-classpath)
 (cider-repl-add-shortcut "history" #'cider-repl-history)
 (cider-repl-add-shortcut "trace-ns" #'cider-toggle-trace-ns)
-(cider-repl-add-shortcut "sideloader-start" #'cider-sideloader-start)
 (cider-repl-add-shortcut "undef" #'cider-undef)
 (cider-repl-add-shortcut "refresh" #'cider-ns-refresh)
 (cider-repl-add-shortcut "reload" #'cider-ns-reload)

test/cider-eval-tests.el

@@ -30,26 +30,6 @@
 
 ;; Please, for each `describe', ensure there's an `it' block, so that its execution is visible in CI.
 
-(describe "cider-provide-file"
-  (let ((tmp-dir (temporary-file-directory)))
-    (it "returns an empty string when the file is not found"
-        (expect (cider-provide-file "abc.clj") :to-equal ""))
-    (it "base64 encodes without newlines"
-        (let ((cider-sideloader-path (list tmp-dir))
-              (default-directory tmp-dir)
-              (filename (make-temp-file "abc.clj")))
-          (with-temp-file filename
-            (dotimes (_ 60) (insert "x")))
-          (expect (cider-provide-file filename) :not :to-match "\n")))
-    (it "can handle multibyte characters"
-        (let ((cider-sideloader-path (list tmp-dir))
-              (default-directory tmp-dir)
-              (filename (make-temp-file "abc.clj"))
-              (coding-system-for-write 'utf-8-unix))
-          (with-temp-file filename
-            (insert "🍻"))
-          (expect (cider-provide-file filename) :to-equal "8J+Nuw==")))))
-
 (describe "cider-extract-error-info"
   (it "Matches Clojure compilation exceptions"
     (expect (cider-extract-error-info cider-compilation-regexp "Syntax error compiling clojure.core/let at (src/haystack/analyzer.clj:18:1).\n[1] - failed: even-number-of-forms? at: [:bindings] spec: :clojure.core.specs.alpha/bindings\n")