From 86ff0ef506c209bb397849706e85cc3a913cb577 Mon Sep 17 00:00:00 2001
From: Friedrich Altheide <friedrich.altheide@w34you.de>
Date: Wed, 26 Nov 2025 06:15:02 +0100
Subject: [PATCH] cargo: add module

---
 .../misc/news/2025/11/2025-11-26_06-33-49.nix |  9 ++++
 modules/programs/cargo.nix                    | 43 +++++++++++++++++++
 tests/modules/programs/cargo/default.nix      |  4 ++
 tests/modules/programs/cargo/empty-config.nix | 14 ++++++
 .../modules/programs/cargo/example-config.nix | 22 ++++++++++
 .../programs/cargo/example-config.toml        |  2 +
 6 files changed, 94 insertions(+)
 create mode 100644 modules/misc/news/2025/11/2025-11-26_06-33-49.nix
 create mode 100644 modules/programs/cargo.nix
 create mode 100644 tests/modules/programs/cargo/default.nix
 create mode 100644 tests/modules/programs/cargo/empty-config.nix
 create mode 100644 tests/modules/programs/cargo/example-config.nix
 create mode 100644 tests/modules/programs/cargo/example-config.toml

diff --git a/modules/misc/news/2025/11/2025-11-26_06-33-49.nix b/modules/misc/news/2025/11/2025-11-26_06-33-49.nix
new file mode 100644
index 00000000..ee5a3515
--- /dev/null
+++ b/modules/misc/news/2025/11/2025-11-26_06-33-49.nix
@@ -0,0 +1,9 @@
+{
+  time = "2025-11-26T05:33:49+00:00";
+  condition = true;
+  message = ''
+    A new module is available: 'programs.cargo'.
+
+    cargo is the build system and package manager of Rust.
+  '';
+}
diff --git a/modules/programs/cargo.nix b/modules/programs/cargo.nix
new file mode 100644
index 00000000..3b83b909
--- /dev/null
+++ b/modules/programs/cargo.nix
@@ -0,0 +1,43 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  inherit (lib) mkEnableOption;
+
+  tomlFormat = pkgs.formats.toml { };
+
+  cfg = config.programs.cargo;
+in
+{
+  meta.maintainers = [ lib.maintainers.friedrichaltheide ];
+
+  options = {
+    programs = {
+      cargo = {
+        enable = mkEnableOption "management of cargo config";
+
+        settings = lib.mkOption {
+          inherit (tomlFormat) type;
+          default = { };
+          description = ''
+            Available configuration options for the .cargo/config see:
+            https://doc.rust-lang.org/cargo/reference/config.html
+          '';
+        };
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home = {
+      file = {
+        ".cargo/config.toml" = {
+          source = tomlFormat.generate "config.toml" cfg.settings;
+        };
+      };
+    };
+  };
+}
diff --git a/tests/modules/programs/cargo/default.nix b/tests/modules/programs/cargo/default.nix
new file mode 100644
index 00000000..34280847
--- /dev/null
+++ b/tests/modules/programs/cargo/default.nix
@@ -0,0 +1,4 @@
+{
+  cargo = ./example-config.nix;
+  cargo-empty-config = ./empty-config.nix;
+}
diff --git a/tests/modules/programs/cargo/empty-config.nix b/tests/modules/programs/cargo/empty-config.nix
new file mode 100644
index 00000000..78aa00f8
--- /dev/null
+++ b/tests/modules/programs/cargo/empty-config.nix
@@ -0,0 +1,14 @@
+{
+  programs.docker-cli = {
+    settings = {
+      net = {
+        git-fetch-with-cli = true;
+      };
+    };
+  };
+
+  nmt.script = ''
+    assertPathNotExists home-files/.cargo/config
+    assertPathNotExists home-files/.cargo/config.toml
+  '';
+}
diff --git a/tests/modules/programs/cargo/example-config.nix b/tests/modules/programs/cargo/example-config.nix
new file mode 100644
index 00000000..7a14fc2a
--- /dev/null
+++ b/tests/modules/programs/cargo/example-config.nix
@@ -0,0 +1,22 @@
+{
+  programs.cargo = {
+    enable = true;
+
+    settings = {
+      net = {
+        git-fetch-with-cli = true;
+      };
+    };
+  };
+
+  nmt.script =
+    let
+      configTestPath = "home-files/.cargo/config.toml";
+    in
+    ''
+      assertPathNotExists home-files/.cargo/config
+      assertFileExists ${configTestPath}
+      assertFileContent ${configTestPath} \
+        ${./example-config.toml}
+    '';
+}
diff --git a/tests/modules/programs/cargo/example-config.toml b/tests/modules/programs/cargo/example-config.toml
new file mode 100644
index 00000000..c91c3f38
--- /dev/null
+++ b/tests/modules/programs/cargo/example-config.toml
@@ -0,0 +1,2 @@
+[net]
+git-fetch-with-cli = true