From 7d3d323e906a06247920c0a8fb2fa473a3770fb9 Mon Sep 17 00:00:00 2001
From: Brian Lyles <brianmlyles@gmail.com>
Date: Thu, 2 Oct 2025 23:53:56 -0500
Subject: [PATCH] git: add `extraArgs` option for difftastic

This option will cover any other arguments that aren't made available
with dedicated options.
---
 modules/programs/git.nix                      | 29 ++++++++++++++-----
 .../programs/git/git-difftastic-expected.conf |  4 +--
 tests/modules/programs/git/git-difftastic.nix |  4 +++
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/modules/programs/git.nix b/modules/programs/git.nix
index 2a0bbad76..94a65747f 100644
--- a/modules/programs/git.nix
+++ b/modules/programs/git.nix
@@ -377,6 +377,18 @@ in
             Determines how the output displays - in one column or two columns.
           '';
         };
+
+        extraArgs = mkOption {
+          type = types.nullOr (types.listOf types.str);
+          default = null;
+          example = [
+            "--tab-width=8"
+            "--sort-paths"
+          ];
+          description = ''
+            Extra command line arguments to pass to {command}`difft`.
+          '';
+        };
       };
 
       delta = {
@@ -837,13 +849,16 @@ in
 
       (
         let
-          difftCommand = concatStringsSep " " [
-            "${lib.getExe cfg.difftastic.package}"
-            "--color ${cfg.difftastic.color}"
-            "--background ${cfg.difftastic.background}"
-            "--display ${cfg.difftastic.display}"
-            "--context ${toString cfg.difftastic.context}"
-          ];
+          difftCommand = concatStringsSep " " (
+            [
+              "${lib.getExe cfg.difftastic.package}"
+              "--color ${cfg.difftastic.color}"
+              "--background ${cfg.difftastic.background}"
+              "--display ${cfg.difftastic.display}"
+              "--context ${toString cfg.difftastic.context}"
+            ]
+            ++ (lib.optionals (cfg.difftastic.extraArgs != null) cfg.difftastic.extraArgs)
+          );
         in
         (lib.mkMerge [
           (mkIf cfg.difftastic.enable {
diff --git a/tests/modules/programs/git/git-difftastic-expected.conf b/tests/modules/programs/git/git-difftastic-expected.conf
index 80c6ba6f0..3603fca31 100644
--- a/tests/modules/programs/git/git-difftastic-expected.conf
+++ b/tests/modules/programs/git/git-difftastic-expected.conf
@@ -1,9 +1,9 @@
 [diff]
-	external = "@difftastic@/bin/difft --color always --background dark --display inline --context 5"
+	external = "@difftastic@/bin/difft --color always --background dark --display inline --context 5 --tab-width=8 --sort-paths"
 	tool = "difftastic"
 
 [difftool "difftastic"]
-	cmd = "@difftastic@/bin/difft --color always --background dark --display inline --context 5 $LOCAL $REMOTE"
+	cmd = "@difftastic@/bin/difft --color always --background dark --display inline --context 5 --tab-width=8 --sort-paths $LOCAL $REMOTE"
 
 [gpg]
 	format = "openpgp"
diff --git a/tests/modules/programs/git/git-difftastic.nix b/tests/modules/programs/git/git-difftastic.nix
index c28e3f263..20fa50c2e 100644
--- a/tests/modules/programs/git/git-difftastic.nix
+++ b/tests/modules/programs/git/git-difftastic.nix
@@ -9,6 +9,10 @@
       color = "always";
       context = 5;
       display = "inline";
+      extraArgs = [
+        "--tab-width=8"
+        "--sort-paths"
+      ];
     };
   };