Make jump-to-definition work in projects needing cider-path-translations

i.e. Dockerized projects.

Fixes #3413

Author: vemv

CHANGELOG.md

@@ -26,6 +26,7 @@
 - [#3393](https://github.com/clojure-emacs/cider/issues/3393): Recompute namespace info on each shadow-cljs recompilation or evaluation.
 - Recompute namespace info on each fighweel-main recompilation.
 - [#3250](https://github.com/clojure-emacs/cider/issues/3250): don't lose the CIDER session over TRAMP files. 
+- [#3413](https://github.com/clojure-emacs/cider/issues/3413): Make jump-to-definition work in projects needing `cider-path-translations` (i.e. Dockerized projects). 
 - Fix the `xref-find-definitions` CIDER backend to return correct filenames.
 - Fix the `cider-xref-fn-deps` buttons to direct to the right file.
 - Make TRAMP functionality work when using non-standard ports.

cider-common.el

@@ -286,22 +286,38 @@ in the container, the alist would be `((\"/src\" \"~/projects/foo/src\"))."
   :group 'cider
   :package-version '(cider . "0.23.0"))
 
-(defun cider--translate-path (path direction)
-  "Attempt to translate the PATH in the given DIRECTION.
+(defun cider--translate-path (path direction &optional return-all)
+  "Attempt to translate the PATH in the given DIRECTION, optionally RETURN-ALL.
 Looks at `cider-path-translations' for (container . host) alist of path
 prefixes and translates PATH from container to host or vice-versa depending on
 whether DIRECTION is 'from-nrepl or 'to-nrepl."
   (seq-let [from-fn to-fn path-fn] (cond ((eq direction 'from-nrepl) '(car cdr identity))
                                          ((eq direction 'to-nrepl) '(cdr car expand-file-name)))
-    (let ((path (funcall path-fn path)))
-      (seq-some (lambda (translation)
-                  (let ((prefix (file-name-as-directory (expand-file-name (funcall from-fn translation)))))
-                    (when (string-prefix-p prefix path)
-                      (replace-regexp-in-string (format "^%s" (regexp-quote prefix))
-                                                (file-name-as-directory
-                                                 (expand-file-name (funcall to-fn translation)))
-                                                path))))
-                cider-path-translations))))
+    (let ((f (lambda (translation)
+               (let ((path (funcall path-fn path))
+                     (prefix (file-name-as-directory (expand-file-name (funcall from-fn translation)))))
+                 (when (string-prefix-p prefix path)
+                   (replace-regexp-in-string (format "^%s" (regexp-quote prefix))
+                                             (file-name-as-directory
+                                              (expand-file-name (funcall to-fn translation)))
+                                             path))))))
+      (if return-all
+          (seq-filter #'identity (mapcar f cider-path-translations))
+        (seq-some f cider-path-translations)))))
+
+(defun cider--all-path-translations ()
+  "Returns `cider-path-translations' if non-empty, else seeks a present value."
+  (or cider-path-translations
+      ;; cider-path-translations often is defined as a directory-local variable,
+      ;; so after jumping to a .jar file, its value can be lost,
+      ;; so we have to figure out a possible translation:
+      (thread-last (buffer-list)
+                   (seq-map (lambda (buffer)
+                              (buffer-local-value 'cider-path-translations buffer)))
+                   (seq-filter #'identity)
+                   (seq-uniq)
+                   (apply #'append)
+                   (seq-uniq))))
 
 (defun cider--translate-path-from-nrepl (path)
   "Attempt to translate the nREPL PATH to a local path."
@@ -336,7 +352,12 @@ If no local or remote file exists, return nil."
           ((and tramp-path (file-exists-p tramp-path))
            tramp-path)
           ((and local-path (file-exists-p local-path))
-           local-path))))
+           local-path)
+          (t
+           (when-let* ((cider-path-translations (cider--all-path-translations)))
+             (thread-last (cider--translate-path local-path 'from-nrepl :return-all)
+                          (seq-filter #'file-exists-p)
+                          car))))))
 
 (declare-function archive-extract "arc-mode")
 (declare-function archive-zip-extract "arc-mode")

cider-connection.el

@@ -614,8 +614,9 @@ REPL defaults to the current REPL."
   (sesman-more-recent-p (cdr session1) (cdr session2)))
 
 (declare-function cider-classpath-entries "cider-client")
-(cl-defmethod sesman-friendly-session-p ((_system (eql CIDER)) session)
-  "Check if SESSION is a friendly session."
+
+(defun cider--sesman-friendly-session-p (session &optional debug)
+  "Check if SESSION is a friendly session, DEBUG optionally."
   (setcdr session (seq-filter #'buffer-live-p (cdr session)))
   (when-let* ((repl (cadr session))
               (proc (get-buffer-process repl))
@@ -644,7 +645,33 @@ REPL defaults to the current REPL."
         (or (seq-find (lambda (path) (string-prefix-p path file))
                       classpath)
             (seq-find (lambda (path) (string-prefix-p path file))
-                      classpath-roots))))))
+                      classpath-roots)
+            (when-let* ((cider-path-translations (cider--all-path-translations))
+                        (translated (cider--translate-path file 'to-nrepl :return-all)))
+              (seq-find (lambda (translated-path)
+                          (or (seq-find (lambda (path)
+                                          (string-prefix-p path translated-path))
+                                        classpath)
+                              (seq-find (lambda (path)
+                                          (string-prefix-p path translated-path))
+                                        classpath-roots)))
+                        translated))
+            (when debug
+              (list file "was not determined to belong to classpath:" classpath "or classpath-roots:" classpath-roots)))))))
+
+(defun cider-debug-sesman-friendly-session-p ()
+  "`message's debugging information relative to friendly sessions.
+
+This is useful for when one sees 'No linked CIDER sessions'
+in an unexpected place."
+  (interactive)
+  (message (prin1-to-string (mapcar (lambda (session)
+                                      (cider--sesman-friendly-session-p session t))
+                                    (sesman--all-system-sessions 'CIDER)))))
+
+(cl-defmethod sesman-friendly-session-p ((_system (eql CIDER)) session)
+  "Check if SESSION is a friendly session."
+  (cider--sesman-friendly-session-p session))
 
 (defvar cider-sesman-browser-map
   (let ((map (make-sparse-keymap)))

dev/docker-sample-project/.dir-locals.el

@@ -0,0 +1,4 @@
+((nil . ((eval . (customize-set-variable 'cider-path-translations
+                                         (list
+                                          (cons "/src" (clojure-project-dir))
+                                          (cons "/root/.m2" (concat (getenv "HOME") "/.m2"))))))))

dev/docker-sample-project/Dockerfile

@@ -0,0 +1,9 @@
+FROM clojure:temurin-17-lein-bullseye
+ENV DEBIAN_FRONTEND=noninteractive
+ENV NREPL_PORT=7888
+WORKDIR /root/app
+COPY . /root/app
+RUN lein deps
+EXPOSE 7888
+RUN lein classpath
+CMD ["lein", "repl", ":headless", ":host", "0.0.0.0", ":port", "7888"]

dev/docker-sample-project/Makefile

@@ -0,0 +1,5 @@
+build:
+	DOCKER_BUILDKIT=0 docker build --no-cache -t cider-docker-dev .
+
+run: build
+	docker run -v $$PWD/src:/app/src -p 7888:7888 cider-docker-dev

dev/docker-sample-project/README.md

@@ -0,0 +1,14 @@
+This project spins up a Clojure project within a Docker image.
+
+The Docker image exposes an nREPL server.
+
+This way, for development purposes, we can exercise CIDER's Docker-related capabilities.
+
+To get started:
+
+* From a terminal tab, run `make run` to run the Docker image
+  * Note that it has a volume mapping for `src`, so any local changes will be visible in the Docker image.
+  * Also note that the root of this subproject has a .dir-locals.el setting up `cider-path-translations`.
+* `M-x cider-connect-clj`, choose localhost, 7888
+* `M-x cider-load-buffer` the foo.clj namespace.
+* From now on, you can `M-.` (jump to definition) recursively, starting from `clj-http.client`.

dev/docker-sample-project/project.clj

@@ -0,0 +1,5 @@
+(defproject cider-docker-dev "0"
+  :dependencies [[org.clojure/clojure "1.11.1"]
+                 [clj-http "3.12.3"]]
+  :source-paths ["src"]
+  :plugins [[cider/cider-nrepl "0.35.0"]])

dev/docker-sample-project/src/bar.clj

@@ -0,0 +1,2 @@
+(ns bar
+  (:require [foo]))

dev/docker-sample-project/src/foo.clj

@@ -0,0 +1,3 @@
+(ns foo
+  (:require
+   [clj-http.client :as client]))

doc/modules/ROOT/pages/config/basic_config.adoc

@@ -201,9 +201,10 @@ To prefer local resources to remote resources (tramp) when both are available:
 
 == Translate File Paths
 
-If you wish to translate file paths from your running instance you may use the
-`cider-path-translations` defcustom to do so. For instance, suppose your app is
-running in a docker container with your source directories mounted there. The
+If you are running Clojure within a Docker image, or doing something similar (i.e. you're `cider-connect`ing to a process,
+and there's a directory mapping for your source paths), you typically need to set `cider-path-translations`
+for jump-to-definition to properly work. For instance, suppose your app is
+running in a docker container with your source directories mounted there as volumes. The
 navigation paths you'd get from nREPL will be relative to the source in the
 docker container rather than the correct path on your host machine. You can add
 translation mappings easily by setting the following (typically in `.dir-locals.el`):