From 925a55de1ee2739f38fdd1c5d20d0d63479268c8 Mon Sep 17 00:00:00 2001
From: Daniel Borchmann <daniel@algebra20.de>
Date: Sat, 27 Aug 2022 16:17:14 +0200
Subject: [PATCH] Include base directory of current git repository in eshell
 prompt

This allows to see of which git repository the current working directory is part
of.

This is also included in Howard Abrams configuration, but he instead determines
the name of the current git repository by looking at `remote.origin.url`.
However, my upstream branch is not always called `origin`, and sometimes there
is no upstream repository at all.  Using the name of the current directory (not
the whole path, though) instead seems to be a good compromise from my point of
view.
---
 site-lisp/db-eshell.el | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/site-lisp/db-eshell.el b/site-lisp/db-eshell.el
index 2f69af7..38c98ad 100644
--- a/site-lisp/db-eshell.el
+++ b/site-lisp/db-eshell.el
@@ -56,16 +56,25 @@
 (defun db/eshell-git-branch-string ()
   ;; Inspired by https://github.com/howardabrams/dot-files/blob/master/emacs-eshell.org#special-prompt
   "Return name of git branch of current directory, as a string.
+
+The format will be BASE-DIR::BRANCH-NAME, where BASE-DIR is the
+directory containing the .git directory or link file of the
+current git repository, and BRANCH-NAME is the name of the
+current branch.
+
 Return the empty string if the current directory is not part of a
 git repository."
   (interactive)
-  (let ((pwd (eshell/pwd)))
-   (when (and (not (file-remote-p pwd))
-              (eshell-search-path "git")
-              (locate-dominating-file pwd ".git"))
-     (save-match-data
-      (string-trim
-       (shell-command-to-string "git rev-parse --abbrev-ref HEAD"))))))
+  (let ((pwd (eshell/pwd))
+        repo-dir)
+    (when (and (not (file-remote-p pwd))
+               (eshell-search-path "git")
+               (setq repo-dir (locate-dominating-file pwd ".git")))
+      (save-match-data
+        (let* ((git-branch (string-trim
+                            (shell-command-to-string "git rev-parse --abbrev-ref HEAD")))
+               (base-dir (file-name-base (string-trim-right repo-dir "/?"))))
+          (format "%s::%s" base-dir git-branch))))))
 
 (defun eshell/default-prompt-function ()
   "A prompt for eshell of the form
@@ -73,9 +82,10 @@ git repository."
    ┌─[$USER@$HOST] [$PWD] (current-git-branch)
    └─
 
-Information about the current git branch will be empty when
-the current directory is not part of a git repository.
-"
+Information about the current git branch will be empty when the
+current directory is not part of a git repository.  See
+`db/eshell-git-branch-string' for more details about the
+formatting."
   (let ((head-face '(:foreground "#859900")))
     (concat (propertize "┌─" 'face head-face)
             (user-login-name)