[Fix #1300] Make it possible to quickly replicate an existing nREPL connection

1 files changed, 37 insertions, 2 deletions

diff --git a/cider-client.el b/cider-client.el
index 19b6c712..4380be98 100644
--- a/cider-client.el
+++ b/cider-client.el
@@ -139,6 +139,10 @@ connections are returned, instead of just the most recent."
             cider-connections
           (car cider-connections)))))
 
+(defun cider-read-connection (prompt)
+  "Completing read for connections using PROMPT."
+  (get-buffer (completing-read prompt (mapcar #'buffer-name (cider-connections)))))
+
 (defun cider-assoc-project-with-connection (&optional project connection)
   "Associate a Clojure PROJECT with an nREPL CONNECTION.
 
@@ -146,7 +150,7 @@ Useful for connections created using `cider-connect', as for them
 such a link cannot be established automatically."
   (interactive)
   (cider-ensure-connected)
-  (let ((conn-buf (or connection (completing-read "Connection: " (mapcar #'buffer-name (cider-connections)))))
+  (let ((conn-buf (or connection (cider-read-connection "Connection: ")))
         (project-dir (or project (read-directory-name "Project directory: " nil (clojure-project-dir) nil (clojure-project-dir)))))
     (when conn-buf
       (with-current-buffer conn-buf
@@ -159,7 +163,7 @@ Useful for connections created using `cider-connect', as for them
 such a link cannot be established automatically."
   (interactive)
   (cider-ensure-connected)
-  (let ((conn (completing-read "Connection: " (cider-connections))))
+  (let ((conn (cider-read-connection "Connection: ")))
     (when conn
       (setq-local cider-connections (list conn)))))
 
@@ -752,6 +756,26 @@ endpoint and Clojure version."
             (cider--clojure-version)
             (cider--nrepl-version))))
 
+(defun cider--connection-properties (conn-buffer)
+  "Extract the essential properties of CONN-BUFFER."
+  (with-current-buffer conn-buffer
+    (list
+     :host (car nrepl-endpoint)
+     :port (cadr nrepl-endpoint)
+     :project-dir nrepl-project-dir)))
+
+(defun cider--connection-host (conn-buffer)
+  "Get CONN-BUFFER's host."
+  (plist-get (cider--connection-properties conn-buffer) :host))
+
+(defun cider--connection-port (conn-buffer)
+  "Get CONN-BUFFER's port."
+  (plist-get (cider--connection-properties conn-buffer) :port))
+
+(defun cider--connection-project-dir (conn-buffer)
+  "Get CONN-BUFFER's project dir."
+  (plist-get (cider--connection-properties conn-buffer) :project-dir))
+
 (defun cider-display-connection-info (&optional show-default)
   "Display information about the current connection.
 
@@ -774,6 +798,17 @@ default connection."
   (message "Default nREPL connection: %s"
            (cider--connection-info (car cider-connections))))
 
+(defun cider-replicate-connection (&optional conn)
+  "Establish a new connection based on an existing connection.
+The new connection will use the same host and port.
+If CONN is not provided the user will be prompted to select a connection."
+  (interactive)
+  (let* ((conn (or conn (cider-read-connection "Select connection to replicate: ")))
+         (host (cider--connection-host conn))
+         (port (cider--connection-port conn))
+         (project-dir (cider--connection-project-dir conn)))
+    (cider-connect host port project-dir)))
+
 (define-obsolete-function-alias 'cider-rotate-connection 'cider-rotate-default-connection "0.10")
 (defun cider-extract-designation-from-current-repl-buffer ()
   "Extract the designation from the cider repl buffer name."