[Fix #501] Nil appearing in nrepl-server buffer name when no project …

…directory.

CHANGELOG.md

@@ -29,6 +29,8 @@ visually distinctive from `cider-repl-output-face` (used for STDOUT output).
 
 ### Bugs fixed
 
+* [#501](https://github.com/clojure-emacs/cider/issues/501) Fix
+nil appearing in nrepl-server buffer name when no project directory.
 * [#493](https://github.com/clojure-emacs/cider/issues/493) Fix rotate connection to handle no
 nREPL connection.
 * [#468](https://github.com/clojure-emacs/cider/issues/468) Fix

nrepl-client.el

@@ -102,6 +102,13 @@ buffer will be hidden.")
   "Apply a prefix to BUFFER-NAME that will hide the buffer."
   (concat (if nrepl-hide-special-buffers " " "") buffer-name))
 
+(defun nrepl-format-buffer-name-template (buffer-name-template designation)
+  "Apply the DESIGNATION to the corresponding BUFFER-NAME-TEMPLATE."
+  (format buffer-name-template
+          (if (> (length designation) 0)
+              (concat nrepl-buffer-name-separator designation)
+            "")))
+
 (defun nrepl-buffer-name (buffer-name-template)
   "Generate a buffer name using BUFFER-NAME-TEMPLATE.
 
@@ -111,10 +118,9 @@ connection port if `nrepl-buffer-name-show-port' is true."
   (generate-new-buffer-name
    (let ((project-name (nrepl--project-name nrepl-project-dir))
          (nrepl-proj-port (cadr nrepl-endpoint)))
-     (format
+     (nrepl-format-buffer-name-template
       buffer-name-template
-      (concat (format "%s%s" nrepl-buffer-name-separator
-                      (if project-name project-name (car nrepl-endpoint)))
+      (concat (if project-name project-name (car nrepl-endpoint))
               (if (and nrepl-proj-port nrepl-buffer-name-show-port)
                   (format ":%s" nrepl-proj-port) ""))))))
 

test/cider-tests.el

@@ -212,6 +212,23 @@
                     (should (equal b3 (current-buffer))))))
               (kill-buffer "*nrepl-connections*"))))))))
 
+(ert-deftest test-nrepl-format-buffer-name-template ()
+  (should (equal "*template designation-foo*"
+                 (nrepl-format-buffer-name-template "*template%s*" "designation-foo"))))
+
+(ert-deftest test-nrepl-format-buffer-name-template-use-separator ()
+  (let ((nrepl-buffer-name-separator "_"))
+    (should (equal "*template_designation-foo*"
+                   (nrepl-format-buffer-name-template "*template%s*" "designation-foo")))))
+
+(ert-deftest test-nrepl-format-buffer-name-template-handle-nil-designation ()
+  (should (equal "*template*"
+                 (nrepl-format-buffer-name-template "*template%s*" nil))))
+
+(ert-deftest test-nrepl-format-buffer-name-template-handle-empty-designation ()
+  (should (equal "*template*"
+                 (nrepl-format-buffer-name-template "*template%s*" ""))))
+
 (ert-deftest test-nrepl-buffer-name ()
   (with-temp-buffer
     (setq-local nrepl-endpoint '("localhost" 1))