helix: add ignores option

modules/programs/helix.nix

@@ -96,6 +96,16 @@ in {
       '';
     };
 
+    ignores = mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+      example = [ ".build/" "!.gitignore" ];
+      description = ''
+        List of paths that should be globally ignored for file picker.
+        Supports the usual ignore and negative ignore (unignore) rules used in `.gitignore` files.
+      '';
+    };
+
     themes = mkOption {
       type = types.attrsOf tomlFormat.type;
       default = { };
@@ -195,6 +205,9 @@ in {
         "helix/languages.toml" = mkIf (cfg.languages != { }) {
           source = tomlFormat.generate "helix-languages-config" cfg.languages;
         };
+        "helix/ignore" = mkIf (cfg.ignores != [ ]) {
+          text = concatStringsSep "\n" cfg.ignores + "\n";
+        };
       };
 
       themes = (mapAttrs' (n: v:

tests/modules/programs/helix/example-settings.nix

@@ -43,6 +43,8 @@ with lib;
         }];
       };
 
+      ignores = [ ".build/" "!.gitignore" ];
+
       themes = {
         base16 = let
           transparent = "none";
@@ -131,6 +133,9 @@ with lib;
       assertFileContent \
         home-files/.config/helix/languages.toml \
         ${./languages-expected.toml}
+      assertFileContent \
+        home-files/.config/helix/ignore \
+        ${./ignore-expected}
       assertFileContent \
         home-files/.config/helix/themes/base16.toml \
         ${./theme-base16-expected.toml}

tests/modules/programs/helix/ignore-expected

@@ -0,0 +1,2 @@
+.build/
+!.gitignore