fix(wpcarro/fish): prefer absolute path for prompt.fish

Also move prompt.fish out of configs, which is a deprecated location.

Change-Id: I95360bc24b0b147a611881ed53e70bf1f9e5deea
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5256
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI

users/wpcarro/dotfiles/config.fish

@@ -25,7 +25,7 @@ set -gx ALTERNATE_EDITOR "emacs -q -nw"
 set -gx VISUAL "emacsclient"
 
 # Use my custom fish prompt
-source ~/.config/fish/prompt.fish
+source /depot/users/wpcarro/dotfiles/prompt.fish
 
 # Configure fuzzy history, file, directory searching
 source (fzf-share)/key-bindings.fish && fzf_key_bindings

users/wpcarro/dotfiles/prompt.fish

@@ -0,0 +1,87 @@
+# When the Emacs SSH client, Tramp, connects to a remote host that uses Fish,
+# it's important to keep the shell prompt simple so that Tramp can parse it.
+if test "$TERM" = "dumb"
+    function fish_prompt
+        echo "\$ "
+    end
+    function fish_right_prompt; end
+    function fish_greeting; end
+    function fish_title; end
+else
+    function fish_prompt
+        # My custom prompt.
+        #
+        # Design objectives:
+        # - max-length <= 80 characters
+        # - minimal
+        # - no dependencies (well, you know what I mean)
+        #
+        # Components
+        # - ssh connection
+        # - user
+        # - host
+        # - git repo
+        # - git branch
+        # - lambda character as prompt
+
+        # Cache status before we overwrite it.
+        set -l last_status $status
+
+        # Colors
+        set -l color_inactive (set_color red --bold)
+        set -l color_active (set_color green --bold)
+        set -l color_normal (set_color normal)
+
+        # SSH information
+        if set -q SSH_CLIENT; or set -q SSH_TTY
+            echo -en "$color_active \bssh ✓ [$color_normal$USER@"(hostname)"$color_active]$color_normal"
+        else
+            echo -en "$color_inactive \bssh ✗ [$color_normal$USER@"(hostname)"$color_inactive]$color_normal"
+        end
+
+        # Separator
+        echo -n " "
+
+        # Git information
+        set -l git_repo (git rev-parse --show-toplevel 2>/dev/null)
+        set -l git_status $status
+
+        if [ (realpath .) = "/" ]
+            set -g dir_path (realpath .)
+        else if [ (realpath ..) = "/" ]
+            set -g dir_path (realpath .)
+        else
+            set -g dir_path (echo (basename (realpath ..))"/"(basename (realpath .)))
+        end
+
+        if test $git_status -eq 0
+            set -l git_repo_name (basename (git rev-parse --show-toplevel))
+            set -l git_branch (git branch 2>/dev/null | grep '^\*' | cut -d' ' -f2-)
+            echo -en "$color_active \bgit ✓ [$color_normal$git_branch$color_active|$color_normal$git_repo_name$color_active|$color_normal$dir_path$color_active]$color_normal"
+        else
+            echo -en "$color_inactive \bgit ✗ [$color_normal$dir_path$color_inactive]$color_normal"
+        end
+
+        # Newline
+        echo
+
+        # Handle root vs non-root
+        if [ "$USER" = "root" ]
+            set -g prompt_sigil "#"
+        else
+            set -g prompt_sigil "λ"
+        end
+
+        set -l time (date +"%T")
+        if test $last_status -eq 0
+            set -l color_prompt (set_color white --bold)
+            echo -n "$time$color_prompt $prompt_sigil$color_normal "
+        else
+            set -l color_prompt (set_color red --bold)
+            echo -n "$time$color_prompt $prompt_sigil$color_normal "
+        end
+    end
+    function fish_right_prompt; end
+    function fish_greeting; end
+    function fish_title; end
+end