example refactor snowflake module system

nix/snow/flake/outputs/checks.nix

@@ -0,0 +1,5 @@
+    checks =
+      inputs.deploy-rs.lib
+      |> mapAttrs (system: deployLib:
+        deployLib.deployChecks deploy);
+

nix/snow/flake/outputs/deploy.nix

@@ -0,0 +1,57 @@
+    deploy.nodes = mapNodes nodes ({
+      name,
+      node,
+      ...
+    }: let
+      inherit
+        (node.deploy)
+        ssh
+        user
+        interactiveSudo
+        remoteBuild
+        rollback
+        autoRollback
+        magicRollback
+        activationTimeout
+        confirmTimeout
+        ;
+
+      nixosFor = system: inputs.deploy-rs.lib.${system}.activate.nixos;
+    in {
+      hostname =
+        if ssh.host != null
+        then ssh.host
+        else "";
+
+      profilesOrder = ["default"]; # profiles priority
+      profiles.default = {
+        path = nixosFor node.system nixosConfigurations.${name};
+
+        user = user;
+        sudo = "sudo -u";
+        interactiveSudo = interactiveSudo;
+
+        fastConnection = false;
+
+        autoRollback = autoRollback -> rollback;
+        magicRollback = magicRollback -> rollback;
+        activationTimeout = activationTimeout;
+        confirmTimeout = confirmTimeout;
+
+        remoteBuild = remoteBuild;
+        sshUser = ssh.user;
+        sshOpts =
+          ssh.opts
+          ++ (
+            if elem "-p" ssh.opts
+            then []
+            else ["-p" (toString ssh.port)]
+          )
+          ++ (
+            if elem "-A" ssh.opts
+            then []
+            else ["-A"]
+          );
+      };
+    });
+

nix/snow/flake/outputs/nixosConfigurations.nix

@@ -0,0 +1,67 @@
+# {
+#   _module = { ... };
+#   _type = "configuration";
+#   class = null;
+#   config = { ... };
+#   extendModules = «lambda extendModules @ /nix/store/9hfp0agnm43kz72l5lpfn9var5p0x2fa-source/lib/modules.nix:340:9»;
+#   graph = [ ... ];
+#   options = { ... };
+#   type = { ... };
+# }
+    nixosConfigurations = mapNodes nodes (
+      {
+        base,
+        lib,
+        name,
+        node,
+        groupModules,
+        ...
+      }: let
+        homeManager =
+          if node.homeManager != null
+          then node.homeManager
+          else if nodes.homeManager != null
+          then nodes.homeManager
+          else
+            warn ''
+              [snowflake] Neither `nodes.homeManager` nor `nodes.nodes.${name}.homeManager` were specified!
+              [snowflake] home-manager will NOT be used! User configuration will be ignored!
+            ''
+            null;
+
+        userArgs = nodes.args // node.args;
+        ceruleanArgs = {
+          inherit systems root base nodes node;
+          inherit (node) system;
+          inherit (this) snow;
+          hostname = name;
+
+          _cerulean = {
+            inherit inputs userArgs ceruleanArgs homeManager;
+            specialArgs = userArgs // ceruleanArgs;
+          };
+        };
+        specialArgs = assert (userArgs
+          |> attrNames
+          |> all (argName:
+            ! ceruleanArgs ? argName
+            || abort ''
+              `specialArgs` are like super important to Cerulean my love... </3
+              But `args.${argName}` is a reserved argument name :(
+            ''));
+          ceruleanArgs._cerulean.specialArgs;
+      in
+        lib.nixosSystem {
+          inherit (node) system;
+          inherit specialArgs;
+          modules =
+            [
+              self.nixosModules.default
+              (this.findImport /${root}/hosts/${name})
+            ]
+            ++ (groupModules root)
+            ++ node.modules
+            ++ nodes.modules;
+        }
+    );
+