refactor: cardanoNix.tests is a perSystem module

checks/testing.nix

@@ -1,88 +1,100 @@
 {
-  config,
   lib,
   inputs,
+  config,
   ...
 }: let
   inherit (lib) mkOption types mapAttrs' nameValuePair;
+  inherit (config.flake) nixosModules;
 in {
-  options.cardanoNix = {
-    tests = mkOption {
-      type = types.lazyAttrsOf (types.submodule ({config, ...}: {
-        options = {
-          name = mkOption {
-            type = types.str;
-            default = config._module.args.name;
-            internal = true;
-          };
-          systems = mkOption {
-            type = types.listOf types.str;
-          };
-          module = mkOption {
-            type = types.deferredModule;
-          };
-        };
-      }));
-    };
-  };
-
-  config.perSystem = {
+  perSystem = {
+    config,
     lib,
     system,
     pkgs,
     ...
-  } @ perSystemArgs: {
-    options.cardanoNix.runTestScript = mkOption {
-      type = types.package;
-      default = pkgs.callPackage ./run-test.nix {inherit (config.cardanoNix) tests;};
-      description = "A convenience script to run tests";
-      internal = true;
-    };
-
-    config = let
-      nixos-lib = import (inputs.nixpkgs.outPath + "/nixos/lib") {};
-      tests =
-        lib.filterAttrs
-        (_: v: lib.elem system v.systems)
-        config.cardanoNix.tests;
-
-      inherit (perSystemArgs.config.cardanoNix) runTestScript;
-    in {
-      checks =
-        mapAttrs'
-        (name: test:
-          nameValuePair "testing-${test.name}"
-          (nixos-lib.runTest {
+  }: let
+    cfg = config.cardanoNix;
+  in {
+    options.cardanoNix = {
+      tests = mkOption {
+        type = types.lazyAttrsOf (types.submodule ({config, ...}: {
+          options = {
+            name = mkOption {
+              type = types.str;
+              default = config._module.args.name;
+              internal = true;
+            };
+            systems = mkOption {
+              type = types.listOf types.str;
+            };
+            module = mkOption {
+              type = types.deferredModule;
+            };
+            documentation = mkOption {
+              type = types.bool;
+              default = false;
+            };
+            specialArgs = mkOption {
+              type = types.attrsOf types.anything;
+              default = {};
+            };
+          };
+        }));
+      };
+      runTestScript = mkOption {
+        type = types.package;
+        default = pkgs.callPackage ./run-test.nix {inherit (cfg) tests;};
+        description = "A convenience script to run tests";
+      };
+      _nixosLib = mkOption {
+        type = types.anything;
+        default = import (inputs.nixpkgs.outPath + "/nixos/lib") {};
+        internal = true;
+      };
+      _mkCheckFromTest = mkOption {
+        type = types.functionTo types.package;
+        internal = true;
+        default = test:
+          (cfg._nixosLib.runTest {
             hostPkgs = pkgs;
 
-            # speed up evaluation by skipping docs
-            defaults.documentation.enable = lib.mkDefault false;
+            # false by default, it speeds up evaluation by skipping docs generation
+            defaults.documentation.enable = test.documentation;
 
-            # make self available in test modules and our custom pkgs
-            node.specialArgs = {
-              inherit pkgs;
+            node = {
+              inherit (test) specialArgs;
             };
 
             # import all of our flake nixos modules by default
             defaults.imports = [
-              config.flake.nixosModules.default
+              nixosModules.default
             ];
 
             # import the test module
             imports = [test.module];
           })
           .config
-          .result)
-        tests;
+          .result;
+      };
+    };
+
+    config = {
+      checks =
+        mapAttrs'
+        (name: test: nameValuePair "testing-${test.name}" (cfg._mkCheckFromTest test))
+        (lib.filterAttrs
+          (_: v: lib.elem system v.systems)
+          cfg.tests);
 
-      apps.run-test.program = lib.getExe runTestScript;
+      apps.run-test.program = lib.getExe cfg.runTestScript;
 
       devshells.default.commands = [
         {
           name = "run-test";
           category = "testing";
           help = "Run tests";
-          command = "${lib.getExe runTestScript} $@";
+          command = "${lib.getExe cfg.runTestScript} $@";
         }
       ];
     };

tests/cardano-cli.nix

@@ -1,4 +1,4 @@
-_: {
+{
   cardanoNix.tests = {
     dummy = {
       systems = ["x86_64-linux"];
@@ -16,6 +16,7 @@ _: {
             cardano-ecosystem.cli.enable = true;
           };
         };
+
         testScript = ''
           # FIXME: check for cardano cli, not git
           machine.succeed("git --version")

tests/default.nix

@@ -1,5 +1,7 @@
 {
-  imports = [
-    ./cardano-cli.nix
-  ];
+  perSystem = _: {
+    imports = [
+      ./cardano-cli.nix
+    ];
+  };
 }