[meta] flakify batou_ext

add a nix flake to batou_ext to build the batou_ext python package as
well as a devshell for development purposes

.github/workflows/nix.yml

@@ -0,0 +1,20 @@
+name: "Nix Test"
+
+# Controls when the workflow will run
+on:
+  # Trigger the workflow on push or pull request events:
+  push:
+    branches: [ master ]
+  pull_request:
+
+  # Allow to run this workflow manually from the Actions tab:
+  workflow_dispatch:
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v20
+    - run: nix build
+    - run: nix flake check

flake.nix

@@ -0,0 +1,68 @@
+{
+  description = "A flake for the flyingcircus batou_ext library";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+    nix-filter.url = "github:numtide/nix-filter";
+  };
+
+  outputs = inputs @ {flake-parts, ...}:
+    flake-parts.lib.mkFlake {inherit inputs;} {
+      imports = [
+        inputs.treefmt-nix.flakeModule
+      ];
+
+      systems = [
+        "x86_64-linux"
+        "aarch64-darwin"
+      ];
+
+      perSystem = {
+        config,
+        pkgs,
+        ...
+      }: let
+        src = inputs.nix-filter.lib {
+          root = inputs.self;
+          exclude = [
+            (inputs.nix-filter.lib.matchExt "nix")
+            "flake.lock"
+          ];
+        };
+        batou_ext = pkgs.python3Packages.callPackage ./nix/batou_ext.nix {inherit src;};
+      in {
+        treefmt = {
+          projectRootFile = "flake.nix";
+          programs.alejandra.enable = true;
+          settings.formatter.alejandra.excludes = [
+            "src/batou_ext/*"
+          ];
+          flakeCheck = false;
+        };
+
+        formatter = config.treefmt.build.wrapper;
+
+        packages = rec {
+          default = batou_ext;
+          inherit batou_ext;
+        };
+
+        checks = {
+          inherit batou_ext;
+        };
+
+        devShells.default = pkgs.mkShell {
+          packages = [
+            (pkgs.python3.withPackages (ps: [batou_ext ps.tox]))
+          ];
+
+          shellHook = ''
+            export APPENV_BASEDIR=$PWD
+          '';
+        };
+      };
+    };
+}

nix/batou_ext.nix

@@ -0,0 +1,56 @@
+{
+  buildPythonPackage,
+  pyyaml,
+  pyaml,
+  six,
+  fetchPypi,
+  src,
+  markupsafe,
+  requests,
+  execnet,
+  importlib-metadata,
+  remote-pdb,
+  py,
+  configupdater,
+  mock,
+  pytest,
+  setuptools,
+  inquirerpy,
+}: let
+  jinja2 = buildPythonPackage rec {
+    pname = "Jinja2";
+    version = "3.0.1";
+    propagatedBuildInputs = [markupsafe];
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "sha256-cD9IS0emr1AudDyRIllcyBKwJx9mFyJAMRT3GnnQ9aQ=";
+    };
+  };
+  batou = buildPythonPackage rec {
+    pname = "batou";
+    version = "2.3.1";
+    propagatedBuildInputs = [
+      requests
+      pyyaml
+      execnet
+      importlib-metadata
+      remote-pdb
+      py
+      configupdater
+      mock
+      pytest
+      setuptools
+      jinja2
+    ];
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "sha256-fPLYvmsNubKfsYWR039CoF7/767EDtXLFNAWhDAg9m4=";
+    };
+  };
+in
+  buildPythonPackage {
+    pname = "batou_ext";
+    version = "latest";
+    propagatedBuildInputs = [pyyaml pyaml six batou inquirerpy];
+    inherit src;
+  }