feat: switch from flake-parts & devenv to rensa + add nixtest

tests/fixtures/example/nixlet.nix

@@ -0,0 +1,6 @@
+{
+  name = "example";
+  version = "0.0.1";
+  description = "hello world";
+  defaultProject = "example";
+}

tests/fixtures/example/values.nix

@@ -0,0 +1,12 @@
+{lib, ...}:
+with lib; {
+  options = {
+    example = mkOption {
+      type = types.str;
+      default = "Hello world!";
+      description = ''
+        Some description.
+      '';
+    };
+  };
+}

tests/lib_test.nix

@@ -0,0 +1,47 @@
+{
+  pkgs,
+  ntlib,
+  nixlet-lib,
+  ...
+}: {
+  suites."Lib Tests" = {
+    pos = __curPos;
+    tests = let
+      nixlet = nixlet-lib.mkNixlet ./fixtures/example;
+    in [
+      {
+        name = "mkNixlet fail on nonexistant nixlet.nix";
+        expected = {
+          success = false;
+          value = false;
+        };
+        actual = builtins.tryEval (nixlet-lib.mkNixlet "/nonexistant").name;
+      }
+      {
+        name = "mkNixlet success";
+        expected = {
+          name = "example";
+          version = "0.0.1";
+          description = "hello world";
+        };
+        actual = {inherit (nixlet) name description version;};
+      }
+      {
+        name = "Nixlet mkDocs";
+        type = "script";
+        script = let
+          docs = nixlet.mkDocs {};
+        in
+          # sh
+          ''
+            ${ntlib.helpers.path [pkgs.gnugrep]}
+            ${ntlib.helpers.scriptHelpers}
+            assert "-f ${docs}" "generated the file"
+            assert_file_contains "${docs}" '`example`'
+            assert_file_contains "${docs}" "Some description."
+            assert_file_contains "${docs}" '"Hello world!"'
+          '';
+      }
+    ];
+  };
+}

tests/render_test.nix

@@ -0,0 +1,30 @@
+{
+  pkgs,
+  ntlib,
+  system,
+  nixlets,
+  ...
+}: {
+  suites."Render Tests" = {
+    pos = __curPos;
+    tests = builtins.map (
+      nixlet: {
+        name = "render ${nixlet.name}";
+        type = "script";
+        script = let
+          output = nixlet.render {inherit system;};
+        in
+          # sh
+          ''
+            ${ntlib.helpers.path [pkgs.gnugrep]}
+            ${ntlib.helpers.scriptHelpers}
+
+            assert "-f ${output}" "should render"
+            assert_file_contains "${output}" "apiVersion"
+            assert_file_contains "${output}" "kubenix/k8s-version"
+            assert_file_contains "${output}" "kubenix/project-name"
+          '';
+      }
+    ) (builtins.attrValues nixlets);
+  };
+}