From e9c599e40c8d0d754980f51e580d00ebef3f2fea Mon Sep 17 00:00:00 2001
From: Friedrich Altheide <11352905+FriedrichAltheide@users.noreply.github.com>
Date: Wed, 23 Jul 2025 17:42:37 +0200
Subject: [PATCH] yarn: add module (#7526)

---
 modules/programs/yarn/default.nix             | 53 +++++++++++++++++++
 tests/modules/programs/yarn/default.nix       |  4 ++
 tests/modules/programs/yarn/empty-config.nix  | 12 +++++
 .../modules/programs/yarn/example-config.nix  | 20 +++++++
 .../modules/programs/yarn/example-config.yml  |  2 +
 5 files changed, 91 insertions(+)
 create mode 100644 modules/programs/yarn/default.nix
 create mode 100644 tests/modules/programs/yarn/default.nix
 create mode 100644 tests/modules/programs/yarn/empty-config.nix
 create mode 100644 tests/modules/programs/yarn/example-config.nix
 create mode 100644 tests/modules/programs/yarn/example-config.yml

diff --git a/modules/programs/yarn/default.nix b/modules/programs/yarn/default.nix
new file mode 100644
index 00000000..1f879218
--- /dev/null
+++ b/modules/programs/yarn/default.nix
@@ -0,0 +1,53 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+let
+  inherit (lib)
+    mkIf
+    mkEnableOption
+    mkOption
+    ;
+
+  cfg = config.programs.yarn;
+
+  yamlFormat = pkgs.formats.yaml { };
+in
+{
+  meta.maintainers = [ lib.maintainers.friedrichaltheide ];
+
+  options.programs.yarn = {
+    enable = mkEnableOption "management of yarn config";
+
+    settings = mkOption {
+      type = yamlFormat.type;
+      default = { };
+      example = ''
+        {
+          httpProxy = "http://proxy.example.org:3128";
+          httpsProxy = "http://proxy.example.org:3128";
+        }
+      '';
+      description = ''
+        Available configuration options for yarn see:
+        <https://yarnpkg.com/configuration/yarnrc>
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    home = {
+      file =
+        let
+          yarnRcFileName = ".yarnrc.yml";
+        in
+        {
+          "${yarnRcFileName}" = {
+            source = yamlFormat.generate "${yarnRcFileName}" cfg.settings;
+          };
+        };
+    };
+  };
+}
diff --git a/tests/modules/programs/yarn/default.nix b/tests/modules/programs/yarn/default.nix
new file mode 100644
index 00000000..86086e95
--- /dev/null
+++ b/tests/modules/programs/yarn/default.nix
@@ -0,0 +1,4 @@
+{
+  yarn = ./example-config.nix;
+  yarn-empty-config = ./empty-config.nix;
+}
diff --git a/tests/modules/programs/yarn/empty-config.nix b/tests/modules/programs/yarn/empty-config.nix
new file mode 100644
index 00000000..9ec25e9c
--- /dev/null
+++ b/tests/modules/programs/yarn/empty-config.nix
@@ -0,0 +1,12 @@
+{
+  programs.yarn = {
+    settings = {
+      httpProxy = "http://proxy.example.org:3128";
+      httpsProxy = "http://proxy.example.org:3128";
+    };
+  };
+
+  nmt.script = ''
+    assertPathNotExists home-files/.yarnrc.yml
+  '';
+}
diff --git a/tests/modules/programs/yarn/example-config.nix b/tests/modules/programs/yarn/example-config.nix
new file mode 100644
index 00000000..baf8c690
--- /dev/null
+++ b/tests/modules/programs/yarn/example-config.nix
@@ -0,0 +1,20 @@
+{
+  programs.yarn = {
+    enable = true;
+
+    settings = {
+      httpProxy = "http://proxy.example.org:3128";
+      httpsProxy = "http://proxy.example.org:3128";
+    };
+  };
+
+  nmt.script =
+    let
+      configPath = "home-files/.yarnrc.yml";
+    in
+    ''
+      assertFileExists ${configPath}
+      assertFileContent ${configPath} \
+        ${./example-config.yml}
+    '';
+}
diff --git a/tests/modules/programs/yarn/example-config.yml b/tests/modules/programs/yarn/example-config.yml
new file mode 100644
index 00000000..1936833d
--- /dev/null
+++ b/tests/modules/programs/yarn/example-config.yml
@@ -0,0 +1,2 @@
+httpProxy: http://proxy.example.org:3128
+httpsProxy: http://proxy.example.org:3128