Sideloader: handle binary files, support multiple directories (#3041)

Make sure that files are served byte-for-byte as they are on disk, without emacs
doing any coding system conversion. This also prevents base64-encode from
complaining about multibyte characters.

Support multiple directories as sources for the sideloader, e.g.
cider-nrepl/src, cider-nrepl/resources, orchard/src.

Author: plexus

CHANGELOG.md

@@ -14,6 +14,7 @@
 * [#3020](https://github.com/clojure-emacs/cider/issues/3020): Fix session linking on Windows, e.g. when jumping into a library on the classpath.
 * [#3031](https://github.com/clojure-emacs/cider/pull/3031): Fix `cider-eval-defun-up-to-point` failing to match delimiters correctly in some cases, resulting in reader exceptions.
 * [#3039](https://github.com/clojure-emacs/cider/pull/3039): Allow starting the sideloader for the tooling session.
+* [#3041](https://github.com/clojure-emacs/cider/pull/3041): Sideloader: handle binary files, support multiple directories
 
 ## 1.1.1 (2021-05-24)
 

cider-eval.el

@@ -189,14 +189,29 @@ When invoked with a prefix ARG the command doesn't prompt for confirmation."
 
 ;;; Sideloader
 
-(defvar cider-sideloader-dir (file-name-directory load-file-name))
+(defvar cider-sideloader-dirs
+  (list (file-name-directory load-file-name))
+  "Directories where we look for resources requested by the sideloader.")
+
+;; based on f-read-bytes
+(defun cider-read-bytes (path)
+  "Read binary data from PATH.
+Return the binary data as unibyte string."
+  (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-provide-file (file)
   "Provide FILE in a format suitable for sideloading."
-  (let ((file (expand-file-name file cider-sideloader-dir)))
-    (if (file-exists-p file)
-        (with-current-buffer (find-file-noselect file)
-          (base64-encode-string (substring-no-properties (buffer-string)) 'no-line-breaks))
+  (let ((file (seq-find
+               #'file-exists-p
+               (seq-map (lambda (dir)
+                          (expand-file-name file dir))
+                        cider-sideloader-dirs))))
+    (if file
+        (base64-encode-string (cider-read-bytes file) 'no-line-breaks)
       ;; if we can't find the file we should return an empty string
       (base64-encode-string ""))))
 
@@ -235,7 +250,8 @@ If CONNECTION is nil, use `cider-current-repl'."
 If CONNECTION is nil, use `cider-current-repl'."
   (interactive)
   (message "Starting nREPL's sideloader")
-  (cider-request:sideloader-start connection))
+  (cider-request:sideloader-start connection)
+  (cider-request:sideloader-start connection 'tooling))
 
 
 ;;; Dealing with compilation (evaluation) errors and warnings

test/cider-eval-test.el

@@ -37,6 +37,13 @@
           (filename (make-temp-file "abc.clj")))
       (with-temp-file filename
         (dotimes (_ 60) (insert "x")))
-      (expect (cider-provide-file filename) :not :to-match "\n"))))
+      (expect (cider-provide-file filename) :not :to-match "\n")))
+  (it "can handle multibyte characters"
+    (let ((cider-sideloader-dir "/tmp")
+          (default-directory "/tmp")
+          (filename (make-temp-file "abc.clj")))
+      (with-temp-file filename
+        (insert "🍻"))
+      (expect (cider-provide-file filename) :to-equal "8J+Nuw=="))))
 
 (provide 'cider-eval-tests)