Add ghostel

README.md

@@ -352,12 +352,21 @@ Caveats:
 ## Terminal DWIM command
 
 I often like using a separate terminal to run most commands, instead of emacs.
-This package provides a `devops-open-terminal-dwim` command, which opens the current source block in a terminal. (Only `ghostty` supported at the moment, but more terminals planned.)
+This package provides a `devops-open-terminal-dwim` command, which opens a terminal at the heading's target (or at `default-directory` when the heading has none).
 
 Any `var` references become environment variables loaded into the (usually remote) 
 shell. The source block content is copied to the clipboard, so you can do 
 `devops-open-terminal-dwim`, then paste, and you will be running the command at the correct location.
 
+`devops-terminal-program` picks the terminal:
+
+- `ghostty` (default): opens an external [Ghostty](https://ghostty.org) window, running `ssh` for a remote target.
+- `ghostel`: opens a [ghostel](https://github.com/dakra/ghostel) terminal inside Emacs, reaching a remote target through TRAMP. Each target gets its own buffer (`*ghostel /ssh:web1:/srv/app/*`), reused on the next call. When that terminal is already open, the `export` lines and the block body are pasted at its prompt, so you only press `RET`. A new terminal gets the variables in its environment, and you yank the body yourself (`C-y`): its shell isn't at a prompt yet, and a paste would run line by line.
+
+```elisp
+(setq devops-terminal-program 'ghostel)
+```
+
 ## devops-lob
 
 `devops.el` uses org's Library of Babel (LOB) to save commonly used server commands. 

devops-test.el

@@ -1706,6 +1706,78 @@ override (issue #14)."
                  '("ghostty" "-e" "ssh" "-t" "example.com"
                    "cd /srv/app && $SHELL"))))
 
+(ert-deftest devops--ghostel-buffer-name-test ()
+  "Each target gets its own ghostel terminal, local or remote."
+  (should (equal (devops--ghostel-buffer-name "/ssh:deploy@example.com:/srv/app/")
+                 "*ghostel /ssh:deploy@example.com:/srv/app/*"))
+  (should-not (equal (devops--ghostel-buffer-name "/ssh:web1:/srv/")
+                     (devops--ghostel-buffer-name "/ssh:web2:/srv/"))))
+
+(ert-deftest devops--ghostel-environment-test ()
+  "Env vars become KEY=VALUE entries, any value printed as text."
+  (should (equal (devops--ghostel-environment '(("FOO" . "a b") ("N" . 3)))
+                 '("FOO=a b" "N=3")))
+  (should-not (devops--ghostel-environment nil)))
+
+(ert-deftest devops--terminal-input-test ()
+  "Exports, shell-quoted, come before the body; nothing to paste is nil."
+  (should (equal (devops--terminal-input '(("FOO" . "a b")) "echo $FOO")
+                 "export FOO=a\\ b\necho $FOO"))
+  (should (equal (devops--terminal-input nil "ls") "ls"))
+  (should (equal (devops--terminal-input '(("N" . 3)) nil) "export N=3"))
+  (should-not (devops--terminal-input nil nil)))
+
+(defvar ghostel-buffer-name)
+(defvar ghostel-environment)
+
+(defmacro devops-test--with-fake-ghostel (&rest body)
+  "Run BODY with a stand-in for the ghostel package.
+`ghostel' records the buffer name and environment it was called with in
+`started' and returns a buffer of that name; `ghostel-paste-string'
+records its text in `pasted'.  Buffers it made are killed afterwards."
+  (declare (indent 0) (debug t))
+  ;; `features' is not special, so it is set and restored, not let-bound.
+  `(let ((saved-features features)
+         (ghostel-buffer-name "*ghostel*")
+         (ghostel-environment '("KEEP=1"))
+         (started nil)
+         (pasted nil))
+     (cl-letf (((symbol-function 'ghostel)
+                (lambda (&optional _arg)
+                  (push (list ghostel-buffer-name ghostel-environment) started)
+                  (get-buffer-create ghostel-buffer-name)))
+               ((symbol-function 'ghostel-paste-string)
+                (lambda (text) (push (list (buffer-name) text) pasted))))
+       (unwind-protect
+           (progn
+             (push 'ghostel features)
+             ,@body)
+         (setq features saved-features)
+         (dolist (s started)
+           (when-let* ((buf (get-buffer (car s))))
+             (kill-buffer buf)))))))
+
+(ert-deftest devops--open-ghostel-new-terminal-test ()
+  "A new terminal gets the env vars in its environment; nothing is pasted."
+  (devops-test--with-local-target dir
+    (devops-test--with-fake-ghostel
+      (devops--open-ghostel dir '(("FOO" . "bar")) "echo $FOO")
+      (should (equal started
+                     `((,(devops--ghostel-buffer-name (file-name-as-directory dir))
+                        ("FOO=bar" "KEEP=1")))))
+      (should-not pasted))))
+
+(ert-deftest devops--open-ghostel-open-terminal-test ()
+  "A terminal already open gets exports and body pasted, not its environment."
+  (devops-test--with-local-target dir
+    (devops-test--with-fake-ghostel
+      (let ((name (devops--ghostel-buffer-name (file-name-as-directory dir))))
+        (get-buffer-create name)
+        (push (list name nil) started)  ; so the macro kills it
+        (devops--open-ghostel dir '(("FOO" . "bar")) "echo $FOO")
+        (should (equal (car started) `(,name ("KEEP=1"))))
+        (should (equal pasted `((,name "export FOO=bar\necho $FOO"))))))))
+
 ;;; Drift detection (devops-drift.el)
 
 (defmacro devops-test--with-drift-check (target org-fmt &rest body)

devops.el

@@ -91,8 +91,12 @@
   :prefix "devops-")
 
 (defcustom devops-terminal-program 'ghostty
-  "Terminal program to use for externally opening target locations."
-  :type '(choice (const ghostty))
+  "Terminal program `devops-open-terminal-dwim' opens target locations in.
+`ghostty' is an external terminal, which reaches a remote target by
+running ssh.  `ghostel' is a terminal inside Emacs, from the ghostel
+package, which reaches it through TRAMP."
+  :type '(choice (const :tag "Ghostty (external)" ghostty)
+                 (const :tag "Ghostel (inside Emacs)" ghostel))
   :group 'devops)
 
 (defcustom devops-enable-session-async nil
@@ -875,13 +879,63 @@ is an alist of (NAME . VALUE) exported in that shell."
           `("ghostty" ,(concat "--working-directory=" dir) "-e" "bash" "-c" ,(concat env-exports " && exec $SHELL"))
         `("ghostty" ,(concat "--working-directory=" dir))))))
 
-(defun devops--open-terminal-at-dir (dir &optional env-vars)
-  "Open `devops-terminal-program' in DIR with ENV-VARS exported."
+(defvar ghostel-buffer-name)
+(defvar ghostel-environment)
+(declare-function ghostel "ghostel" (&optional arg))
+(declare-function ghostel-paste-string "ghostel" (string))
+
+(defun devops--ghostel-buffer-name (dir)
+  "Return the name of the ghostel terminal for DIR, one per target."
+  (format "*ghostel %s*" (abbreviate-file-name dir)))
+
+(defun devops--ghostel-environment (env-vars)
+  "Return ENV-VARS, an alist of (NAME . VALUE), as `ghostel-environment'."
+  (mapcar (lambda (pair) (format "%s=%s" (car pair) (cdr pair)))
+          env-vars))
+
+(defun devops--terminal-input (env-vars body)
+  "Return the text to paste at a shell prompt, or nil.
+ENV-VARS, an alist of (NAME . VALUE), become `export' lines ahead of
+BODY, which may be nil."
+  (let ((lines (append (mapcar (lambda (pair)
+                                 (format "export %s=%s" (car pair)
+                                         (shell-quote-argument
+                                          (format "%s" (cdr pair)))))
+                               env-vars)
+                       (and body (list body)))))
+    (and lines (string-join lines "\n"))))
+
+(defun devops--open-ghostel (dir env-vars body)
+  "Pop to the ghostel terminal for DIR, with ENV-VARS exported.
+A new terminal starts with ENV-VARS in its environment.  A terminal
+already open gets ENV-VARS and BODY pasted at its prompt, not run.
+A new one does not, since its shell would run each pasted line as it
+started; BODY is in the kill ring for it."
+  (unless (require 'ghostel nil t)
+    (user-error "Package ghostel is not installed"))
+  (let* ((default-directory (file-name-as-directory (expand-file-name dir)))
+         (ghostel-buffer-name (devops--ghostel-buffer-name default-directory))
+         (open (get-buffer ghostel-buffer-name))
+         (ghostel-environment (append (unless open
+                                        (devops--ghostel-environment env-vars))
+                                      ghostel-environment))
+         (buf (ghostel)))
+    (when-let* ((open)
+                (text (devops--terminal-input env-vars body)))
+      (with-current-buffer buf
+        (ghostel-paste-string text)))))
+
+(defun devops--open-terminal-at-dir (dir &optional env-vars body)
+  "Open `devops-terminal-program' in DIR with ENV-VARS exported.
+BODY, a src block's body or nil, is for the program to offer at the
+prompt."
   (pcase devops-terminal-program
     ('ghostty
      (let ((ghostty (devops--ghostty-command dir env-vars)))
        (message "Calling process:\n%s" (string-join ghostty " "))
-       (apply #'start-process "devops-terminal" nil ghostty)))))
+       (apply #'start-process "devops-terminal" nil ghostty)))
+    ('ghostel
+     (devops--open-ghostel dir env-vars body))))
 
 (defun devops-src-block-env-vars ()
   "Return alist of evaluated :var params from current src block."
@@ -909,16 +963,21 @@ is an alist of (NAME . VALUE) exported in that shell."
 
 ;;;###autoload
 (defun devops-open-terminal-dwim ()
-  "Open terminal at contextual directory.
-In a src block, if the : copies body to clipboard and exports :var env vars."
+  "Open `devops-terminal-program' at the heading's target.
+With no target, open it in `default-directory'.  In a shell src block,
+export the block's :var arguments as environment variables and copy its
+body to the kill ring.  Ghostel also pastes them at the prompt of a
+terminal already open at the target."
   (interactive)
-  (let* ((dir (devops--heading-target-dir))
+  (let* ((dir (or (devops--heading-target-dir) default-directory))
          (env-vars (devops-src-block-env-vars))
-         (lang (org-element-property :language (org-element-at-point))))
-    (when (or (string= lang "shell") (string= lang "sh"))
-      (kill-new (devops--src-block-body))
+         (lang (org-element-property :language (org-element-at-point)))
+         (body (and (member lang '("shell" "sh"))
+                    (devops--src-block-body))))
+    (when body
+      (kill-new body)
       (message "Source block copied to kill ring."))
-    (devops--open-terminal-at-dir dir env-vars)))
+    (devops--open-terminal-at-dir dir env-vars body)))
 
 (defun devops-unload-function ()
   "Turn `devops-mode' off, removing its advice before unloading.