WIP: ADD NOTE FOR FUTURE SELF

They have a custom `jj` with Piper CitC integration.

hosts/homes/ambroisie@bazin/default.nix

@@ -22,6 +22,10 @@
       package = pkgs.emptyDirectory;
     };
 
+    jujutsu = {
+      package = pkgs.emptyDirectory;
+    };
+
     tmux = {
       # I use scripts that use the passthrough sequence often on this host
       enablePassthrough = true;

hosts/homes/ambroisie@mousqueton/default.nix

@@ -25,6 +25,10 @@
       package = pkgs.emptyDirectory;
     };
 
+    jujutsu = {
+      package = pkgs.emptyDirectory;
+    };
+
     tmux = {
       # I use scripts that use the passthrough sequence often on this host
       enablePassthrough = true;

modules/home/delta/default.nix

@@ -11,6 +11,10 @@ in
     git = {
       enable = my.mkDisableOption "git integration";
     };
+
+    jujutsu = {
+      enable = my.mkDisableOption "jujutsu integration";
+    };
   };
 
   config = lib.mkIf cfg.enable {
@@ -45,5 +49,26 @@ in
         };
       };
     };
+
+    # `jj log -p` does not use `delta`
+    # https://github.com/jj-vcs/jj/issues/4142
+    programs.jujutsu = lib.mkIf cfg.jujutsu.enable {
+      settings = {
+        merge-tools = {
+          delta = {
+            # Errors are signaled with exit codes greater or equal to 2
+            diff-expected-exit-codes = [ 0 1 ];
+          };
+        };
+
+        ui = {
+          # Delta expects a `git diff` input
+          diff-formatter = ":git";
+
+          # `finalPackage` automatically applied `--config` if necessary
+          pager = [ (lib.getExe config.programs.delta.finalPackage) ];
+        };
+      };
+    };
   };
 }

modules/home/jujutsu/default.nix

@@ -35,9 +35,68 @@ in
         };
 
         aliases = {
-          jj = [ "util" "exec" "--" "jj" ];
+          jj = [ ];
+          # FIXME:
+          # * still not a big fan of the template
           lol = [ "log" "-r" "..@" "-T" "builtin_log_oneline" ];
           lola = [ "lol" "-r" "all()" ];
+          # FIXME: equivalent to `git switch -`
+          # See https://github.com/jj-vcs/jj/issues/2871
+          # Might be broken recently https://discord.com/channels/968932220549103686/1380272574709366989/1380432041983606855
+          # TODO:
+          # * `pick` (https://github.com/jj-vcs/jj/issues/5446): [ "util" "exec" "--" "bash" "-c" "jj log -p -r \"diff_contains($1)\"" "" ]
+          # * `root`: `jj workspace root` (barely necessary then)
+        };
+
+        # FIXME: git equivalents
+        # I'd like a better formatted blame (more like delta's?)
+        # blame = {
+        #   coloring = "repeatedLines";
+        #   markIgnoredLines = true;
+        #   markUnblamables = true;
+        # };
+        # FIXME: log colors should probably match git
+        # FIXME: patience diff?
+        # FIXME: fetch prune/pruneTags?
+        # FIXME: pull.rebase=true? Probably true TBH
+        # FIXME: push.default=simple? Probably true TBH
+        # FIXME: conflict style? ui.conflict-marker-style=git is diff3, not zdiff3. Default looks fine-ish
+
+        # FIXME: from ma_9's config, plus my own stuff
+        # snapshot = {
+        #   auto-track = "none()";
+        # };
+        #
+        # ui = {
+        #   diff-editor = ":builtin"; # To silence hints
+        #   movement = {
+        #     edit = false;
+        #   };
+        # };
+
+        templates = {
+          # Equivalent to `commit.verbose = true` in Git
+          draft_commit_description = "commit_description_verbose(self)";
+        };
+
+        template-aliases = {
+          "commit_description_verbose(commit)" = ''
+            concat(
+              commit_description(commit),
+              "JJ: ignore-rest\n",
+              diff.git(),
+            )
+          '';
+          # FIXME: use `diff.summary()` instead? Supported by syntax highlighting
+          # See https://github.com/jj-vcs/jj/issues/1946#issuecomment-2572986485
+          # FIXME: tree-sitter grammar isn't in `nvim-treesitter` (https://github.com/kareigu/tree-sitter-jjdescription)
+          "commit_description(commit)" = ''
+            concat(
+              commit.description(), "\n",
+              "JJ: This commit contains the following changes:\n",
+              indent("JJ:    ", diff.stat(72)),
+            )
+          '';
         };
 
         "--scope" = [
@@ -63,5 +122,10 @@ in
         ];
       };
     };
+
+    # To drop in a `local.toml` configuration, not-versioned
+    xdg.configFile = {
+      "jj/conf.d/.keep".text = "";
+    };
   };
 }