chore: initial prototype

lib/default.nix

@@ -0,0 +1,31 @@
+{pkgs, ...}: {
+  mkTest = {
+    type ? "unit",
+    name,
+    description ? "",
+    expected ? null,
+    actual ? null,
+    actualDrv ? null,
+    pos ? null,
+  }: {
+    inherit type name description expected actual;
+    actualDrv = actualDrv.drvPath or "";
+    pos =
+      if pos == null
+      then ""
+      else "${pos.file}:${toString pos.line}:${toString pos.column}";
+  };
+  mkSuite = name: tests: {
+    inherit name tests;
+  };
+  exportSuites = suites: let
+    suitesList =
+      if builtins.isList suites
+      then suites
+      else [suites];
+    testsMapped = builtins.toJSON suitesList;
+  in
+    pkgs.runCommand "tests.json" {} ''
+      echo '${testsMapped}' > $out
+    '';
+}

lib/flake.nix

@@ -0,0 +1,6 @@
+{
+  outputs = inputs: {
+    lib = import ./.;
+    flakeModule = import ./flakeModule.nix;
+  };
+}

lib/flakeModule.nix

@@ -0,0 +1,41 @@
+{
+  flake-parts-lib,
+  lib,
+  ...
+}: let
+  inherit (lib) mkOption types;
+in {
+  options.perSystem = flake-parts-lib.mkPerSystemOption (
+    {
+      config,
+      pkgs,
+      ...
+    }: let
+      nixtests-lib = import ./. {inherit pkgs;};
+    in {
+      options.testSuites = mkOption {
+        type = types.attrsOf (types.listOf types.attrs);
+        default = {};
+      };
+
+      config.legacyPackages = rec {
+        "nixtests" = let
+          suites = map (suiteName: let
+            tests = builtins.getAttr suiteName config.testSuites;
+          in
+            nixtests-lib.mkSuite
+            suiteName
+            (map (test: nixtests-lib.mkTest test) tests))
+          (builtins.attrNames config.testSuites);
+        in
+          nixtests-lib.exportSuites suites;
+        "nixtests:run" = let
+          program = pkgs.callPackage ./../package.nix {};
+        in
+          pkgs.writeShellScriptBin "nixtests:run" ''
+            ${program}/bin/nixtest --tests=${nixtests} "$@"
+          '';
+      };
+    }
+  );
+}