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

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 "0.35.1"]])

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

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

dev/sample-project/Dockerfile → dev/tramp-sample-project/Dockerfile

@@ -1,10 +1,5 @@
-# Use an official Clojure runtime as a parent image
 FROM clojure:temurin-17-lein-bullseye
-
-# Set environment variables to non-interactive (this prevents some prompts)
 ENV DEBIAN_FRONTEND=noninteractive
-
-# Define environment variable for nREPL port
 ENV NREPL_PORT=7888
 
 RUN apt-get update \
@@ -21,7 +16,6 @@ RUN locale-gen en_US.UTF-8
 RUN locale-gen en en_US en_US.UTF-8
 RUN dpkg-reconfigure locales
 
-# Set root password
 RUN echo 'root:cider' | chpasswd
 
 RUN sed -i 's/^#* *PasswordAuthentication .*/PasswordAuthentication yes/' /etc/ssh/sshd_config
@@ -31,31 +25,20 @@ RUN sed -i 's/^#* *ChallengeResponseAuthentication .*/ChallengeResponseAuthentic
 # SSH login fix. Otherwise user is kicked off after login
 RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd
 
-# Expose SSH port
 EXPOSE 22
 
 CMD ["/usr/sbin/sshd", "-D"]
 
-# Set the working directory in the docker image
 WORKDIR /usr/src/app
 
-# Copy the current directory contents into the directory at /usr/src/app in the image
 COPY . /usr/src/app
 
-# Install any needed packages specified in project.clj
 RUN lein deps
 
-# Forward all relevant env vars for ssh sessions
 RUN echo "export JAVA_HOME=${JAVA_HOME}" >> /root/.bashrc
 RUN echo "export LEIN_HOME=${LEIN_HOME}" >> /root/.bashrc
 RUN echo "export LEIN_JAVA_CMD=${LEIN_JAVA_CMD}" >> /root/.bashrc
 RUN echo "export LEIN_JVM_OPTS=${LEIN_JVM_OPTS}" >> /root/.bashrc
 RUN echo "export LEIN_ROOT=${LEIN_ROOT}" >> /root/.bashrc
 RUN echo "export NREPL_PORT=${NREPL_PORT}" >> /root/.bashrc
 RUN echo "export PATH=${PATH}" >> /root/.bashrc
-
-# Make port 7888 available to the world outside this container (nREPL default port)
-#EXPOSE 7888
-
-# Run lein repl when the container launches, on port defined by NREPL_PORT
-#CMD ["lein", "repl", ":headless", ":host", "0.0.0.0", ":port", "7888"]

dev/sample-project/project.clj → dev/tramp-sample-project/project.clj

@@ -2,4 +2,4 @@
   :dependencies [[org.clojure/clojure "1.11.1"]
                  [clj-http "3.12.3"]]
   :source-paths ["src"]
-  :plugins [[cider/cider-nrepl "0.35.0"]])
+  :plugins [[cider/cider-nrepl "0.35.1"]])

dev/tramp-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`):
@@ -237,6 +238,14 @@ different configurations.
 In this example, the path `/src` will be translated to the correct path of your
 Clojure project on the host machine. And `/root/.m2` to the host's `~/.m2` folder.
 
+You need to run `lein deps` (or `clojure -P`, etc) in the host machine in order for
+navigation to fully work, at least once, and then, preferably, every time your Maven dependencies change.
+This allows the `.m2` part of `cider-path-translations` to be actually useful.
+
+If you can't or won't do that, you can use TRAMP capabilities (which CIDER supports) instead of
+setting up `cider-path-translations`. For that, you'd typically need to set up a SSH daemon
+within your Docker image. 
+
 == Filter out namespaces in certain namespace-related commands
 
 You can hide all nREPL middleware details from `cider-browse-ns*` and `cider-apropos*`

doc/modules/ROOT/pages/troubleshooting.adoc

@@ -352,3 +352,17 @@ You can disable this Paredit behaviour by adding the following to your `init.el`
 ----
 (define-key paredit-mode-map (kbd "RET") nil)
 ----
+
+=== Interactions fail with `No linked CIDER sessions`
+
+If any interactive feature is being shortcircuited for you with the message `No linked CIDER sessions`,
+that's due to one of the following reasons:
+
+* You're evaluating code in a buffer from a project that hasn't started a repl
+  * You can fix this by switching instead to a project that has.
+  * You can also, simply, start a repl in the current project.
+* There's a bug in the CIDER/Sesman integration
+  * Session linking generally works by determining whether the current buffer is related to the classpath of some REPL.
+  * You can obtain debug info echoed to the `*messages*` buffer by running `M-x cider-debug-sesman-friendly-session-p` on the problematic buffer.
+    * By reading it, you might be able to determine why CIDER failed to see the relationship between `(buffer-filename)` and the classpath.
+    * Feel free to created a detailed GitHub issue including this information.