fish: functions: Add jujutsu information to prompt

fish shell prompt for jujutsu is copied from
https://gist.github.com/hroi/d0dc0e95221af858ee129fd66251897e

fish/.config/fish/functions/fish_jj_prompt.fish

@@ -0,0 +1,38 @@
+function fish_jj_prompt --description 'Write out the jj prompt'
+    if not command -sq jj
+        return 1
+    end
+
+    if not jj root --quiet &>/dev/null
+        return 1
+    end
+
+    jj log --ignore-working-copy --no-graph --color always -r @ -T '
+        surround(
+            " (",
+            ")",
+            separate(
+                " ",
+                bookmarks.join(", "),
+                coalesce(
+                    surround(
+                        "\"",
+                        "\"",
+                        if(
+                            description.first_line().substr(0, 24).starts_with(description.first_line()),
+                            description.first_line().substr(0, 24),
+                            description.first_line().substr(0, 23) ++ "…"
+                        )
+                    ),
+                    "(no description set)"
+                ),
+                change_id.shortest(),
+                commit_id.shortest(),
+                if(conflict, "(conflict)"),
+                if(empty, "(empty)"),
+                if(divergent, "(divergent)"),
+                if(hidden, "(hidden)"),
+            )
+        )
+    '
+end

fish/.config/fish/functions/fish_prompt.fish

@@ -31,7 +31,8 @@ function fish_prompt
     end
     echo -n ' '
 
-    fish_custom_git_prompt
+    fish_jj_prompt
+    or fish_custom_git_prompt
 
     if [ "$command_status" -eq 0 ]
         set_color brcyan