mypy: init module (#7656)

modules/programs/mypy.nix

@@ -0,0 +1,50 @@
+{
+  pkgs,
+  config,
+  lib,
+  ...
+}:
+
+let
+
+  iniFormat = pkgs.formats.ini { };
+  cfg = config.programs.mypy;
+
+in
+{
+  meta.maintainers = [ ];
+
+  options.programs.mypy = {
+    enable = lib.mkEnableOption "mypy";
+
+    package = lib.mkPackageOption pkgs "mypy" { nullable = true; };
+
+    settings = lib.mkOption {
+      type = iniFormat.type;
+      default = { };
+      example = lib.literalExpression ''
+        {
+          mypy = {
+            warn_return_any = true;
+            warn_unused_configs = true;
+          };
+        }
+      '';
+      description = ''
+        Configuration written to
+        {file}`$XDG_CONFIG_HOME/mypy/config`.
+
+        See <https://mypy.readthedocs.io/en/stable/config_file.html>
+        for more information.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home.packages = lib.mkIf (cfg.package != null) [ cfg.package ];
+
+    xdg.configFile."mypy/config" = lib.mkIf (cfg.settings != { }) {
+      source = iniFormat.generate "mypy-config" cfg.settings;
+    };
+  };
+}

tests/modules/programs/mypy/basic-config.nix

@@ -0,0 +1,47 @@
+{ pkgs, ... }:
+
+{
+  programs.mypy = {
+    enable = true;
+
+    package = pkgs.mypy;
+
+    settings = {
+      mypy = {
+        warn_return_any = true;
+        warn_unused_configs = true;
+      };
+
+      "mypy-mycode.foo.*" = {
+        disallow_untyped_defs = true;
+      };
+
+      "mypy-mycode.bar".warn_return_any = false;
+
+      "mypy-somelibrary".ignore_missing_imports = true;
+    };
+  };
+
+  nmt.script =
+    let
+      configFile = "home-files/.config/mypy/config";
+    in
+    ''
+      assertFileExists ${configFile}
+      assertFileContent ${configFile} \
+        ${pkgs.writeText "settings-expected" ''
+          [mypy]
+          warn_return_any=true
+          warn_unused_configs=true
+
+          [mypy-mycode.bar]
+          warn_return_any=false
+
+          [mypy-mycode.foo.*]
+          disallow_untyped_defs=true
+
+          [mypy-somelibrary]
+          ignore_missing_imports=true
+        ''}
+    '';
+}

tests/modules/programs/mypy/default.nix

@@ -0,0 +1,3 @@
+{
+  mypy-basic-config = ./basic-config.nix;
+}