swap out the input types to hopefully trigger an evaluation error - unfortunately does not seem to work yet

deployment/data-model-test.nix

@@ -185,7 +185,6 @@ in
           deploymentFunction = lib.isFunction result.deploymentFunction;
           getProviders = lib.isFunction result.getProviders;
         };
-        deploy = lib.isFunction fediversity.deployments.example.deployment;
       };
     expected = {
       number-of-resources = 1;

deployment/data-model.nix

@@ -143,7 +143,7 @@ in
             resource-mapping = mkOption {
               description = "Function type for the mapping from resources to a (NixOps4) deployment";
               type = functionType;
-              # readOnly = true;
+              readOnly = true;
               default = {
                 # input-type = application-resources;
                 input-type = types.int;
@@ -203,14 +203,14 @@ in
             };
             environment = mkOption {
               description = "The run-time environment to deploy to";
-              type = options.environments.type.nestedTypes.elemType;
+              type = options.environments.nestedType;
             };
             # TODO(@fricklerhandwerk): maybe this should be a separate thing such as `fediversity-setup`,
             # which makes explicit which applications and environments are available.
             # then the deployments can simply be the result of the function application baked into this module.
             deployment = mkOption {
               description = "Generate a deployment from a configuration, by applying an environment's resource policies to the applications' resource mappings";
-              type = deployment.config.environment.resource-mapping.output-type;
+              type = functionTo deployment.config.environment.resource-mapping.output-type;
               readOnly = true;
               # TODO: check cfg.enable.true
               default =

deployment/function.nix

@@ -20,7 +20,7 @@ submodule (function: {
     };
     function-type = mkOption {
       type = optionType;
-      # readOnly = true;
+      readOnly = true;
       default = functionTo (submodule {
         options = {
           input = mkOption {