feat: add github workflows and nix checks

.github/workflows/build-library.yml

@@ -0,0 +1,13 @@
+name: Build with Nix
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    - uses: DeterminateSystems/nix-installer-action@main
+    - uses: DeterminateSystems/magic-nix-cache-action@main
+    - run: nix build '.?submodules=1#squirrel'

.github/workflows/test.yml

@@ -0,0 +1,13 @@
+name: Test with Nix
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    - uses: DeterminateSystems/nix-installer-action@main
+    - uses: DeterminateSystems/magic-nix-cache-action@main
+    - run: nix flake check -v

.gitignore

@@ -1,3 +1,6 @@
+# Nix ignores
+result
+
 # CMake ignores
 CMakeLists.txt.user
 CMakeCache.txt

default.nix

@@ -0,0 +1,34 @@
+{ lib
+, gcc
+, gnumake
+, cmake
+, stdenv
+}:
+
+stdenv.mkDerivation {
+  pname = "squirrel";
+  version = "0.0.0";
+
+  src = ./.;
+
+  nativeBuildInputs = [ cmake gnumake ];
+  buildInputs = [ ];
+
+  cmakeFlags = [
+    "-DCMAKE_BUILD_TYPE=Release"
+    "-DCMAKE_C_COMPILER=${gcc}/bin/gcc"
+    "-DCMAKE_CXX_COMPILER=${gcc}/bin/g++"
+  ];
+
+  installPhase = ''cp -r . $out'';
+
+  checkPhase = ''make -C ./build test'';
+
+  meta = with lib; {
+    homepage = "https://github.com/headblockhead/squirrel";
+    description = "Keyboard firmware library inspired by QMK.";
+    licencse = licenses.mit;
+    platforms = with platforms; linux;
+  };
+}
+

flake.nix

@@ -1,7 +1,7 @@
 {
-  description = "Tools for developing and building SQUIRREL";
+  description = "Tools for developing, building and testing SQUIRREL";
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
     flake-utils.url = "github:numtide/flake-utils";
     xc.url = "github:joerdav/xc";
   };
@@ -14,25 +14,30 @@
             overlays = [
               (final: prev: {
                 xc = inputs.xc.packages.x86_64-linux.xc;
+                picotool = pkgs.callPackage ./picotool.nix {
+                  pico-sdk = pkgs.callPackage ./pico-sdk.nix { };
+                };
+                pico-sdk = pkgs.callPackage ./pico-sdk.nix { };
               })
             ];
           };
         in
         {
-          packages.default = pkgs.callPackage ./default.nix { };
+          # Development shell (nix develop)
           devShells.default = pkgs.mkShell {
-            buildInputs = [
-              inputs.xc
-
-              pkgs.cmake
-              pkgs.gcc
-              pkgs.ccls
-              pkgs.python39
-              pkgs.gnumake
-              pkgs.git
-              pkgs.cacert
+            buildInputs = with pkgs; [
+              xc
+              cmake
+              gcc
+              ccls
+              gnumake
+              git
+              cacert
             ];
           };
+          # The firmware (nix build)
+          packages.squirrel = pkgs.callPackage ./default.nix { };
+          checks.squirrel-tests = pkgs.callPackage ./tests.nix { };
         }
       );
 }

tests.nix

@@ -0,0 +1,35 @@
+{ lib
+, gcc
+, gnumake
+, cmake
+, stdenv
+}:
+
+stdenv.mkDerivation {
+  pname = "squirrel-tests";
+  version = "0.0.0";
+
+  src = ./.;
+
+  nativeBuildInputs = [ cmake gnumake ];
+  buildInputs = [ ];
+
+  cmakeFlags = [
+    "-DCMAKE_BUILD_TYPE=Testing"
+    "-DCMAKE_C_COMPILER=${gcc}/bin/gcc"
+    "-DCMAKE_CXX_COMPILER=${gcc}/bin/g++"
+  ];
+
+  installPhase = ''
+    cd tests
+    ctest --timeout 60 # tests should never take longer than 60 seconds each to complete.
+    cp -r . $out'';
+
+  meta = with lib; {
+    homepage = "https://github.com/headblockhead/squirrel";
+    description = "Keyboard firmware library inspired by QMK.";
+    licencse = licenses.mit;
+    platforms = with platforms; linux;
+  };
+}
+