Add support for null literal values

app/graphql/mutations/namespaces/projects/flows/update.rb

@@ -14,7 +14,7 @@ class Update < BaseMutation
 
           argument :flow_input, Types::Input::FlowInputType, description: 'The updated flow', required: true
 
-          def resolve(flow_id:, flow_input:, **_params)
+          def resolve(flow_id:, flow_input:)
             flow = SagittariusSchema.object_from_id(flow_id)
 
             return { errors: [create_error(:flow_not_found, 'Flow does not exist')] } if flow.nil?

app/graphql/types/input/node_parameter_input_type.rb

@@ -8,7 +8,7 @@ class NodeParameterInputType < Types::BaseInputObject
       argument :parameter_definition_id, Types::GlobalIdType[::ParameterDefinition],
                required: true, description: 'The identifier of the Parameter Definition'
 
-      argument :value, Types::Input::NodeParameterValueInputType, required: false,
+      argument :value, Types::Input::NodeParameterValueInputType, required: true,
                                                                   description: 'The value of the parameter'
     end
   end

app/graphql/types/literal_value_type.rb

@@ -5,10 +5,12 @@ class LiteralValueType < Types::BaseObject
     description 'Represents a literal value, such as a string or number.'
 
     field :value, GraphQL::Types::JSON,
-          null: false,
-          description: 'The literal value itself as JSON.',
-          method: :itself
+          null: true,
+          description: 'The literal value itself as JSON.'
 
-    timestamps
+    # can't use method: :itself on the field because that turns {} into null
+    def value
+      object
+    end
   end
 end

app/graphql/types/node_parameter_type.rb

@@ -11,12 +11,12 @@ class NodeParameterType < Types::BaseObject
     field :value, Types::NodeParameterValueType, null: true, description: 'The value of the parameter'
 
     def value
-      if object.literal_value.present?
-        object.literal_value
-      elsif object.reference_value.present?
+      if object.reference_value.present?
         object.reference_value
       elsif object.function_value_id.present?
         object.function_value
+      else
+        object.literal_value
       end
     end
 

app/models/node_parameter.rb

@@ -16,12 +16,12 @@ def to_grpc
 
     param.value = Tucana::Shared::NodeValue.new(literal_value: Tucana::Shared::Value.from_ruby({}))
 
-    if literal_value.present?
-      param.value.literal_value = Tucana::Shared::Value.from_ruby(literal_value)
-    elsif reference_value.present?
+    if reference_value.present?
       param.value.reference_value = reference_value.to_grpc
     elsif function_value.present?
       param.value.node_function_id = function_value.id
+    else
+      param.value.literal_value = Tucana::Shared::Value.from_ruby(literal_value)
     end
 
     param
@@ -31,9 +31,8 @@ def to_grpc
 
   def only_one_value_present
     values = [!literal_value.nil?, reference_value.present?, function_value.present?]
-    return if values.count(true) == 1
+    return if values.count(true) <= 1
 
-    errors.add(:value,
-               'Exactly one of literal_value, reference_value, or function_value must be present')
+    errors.add(:value, 'Only one of literal_value, reference_value, or function_value must be present')
   end
 end

app/models/reference_value.rb

@@ -3,7 +3,7 @@
 class ReferenceValue < ApplicationRecord
   belongs_to :node_function # real value association
   belongs_to :data_type_identifier
-  has_many :reference_paths, inverse_of: :reference_value, autosave: true
+  has_many :reference_paths, inverse_of: :reference_value, autosave: true, dependent: :destroy
   has_many :node_parameters, inverse_of: :reference_value
 
   def to_grpc

app/services/namespaces/projects/flows/update_service.rb

@@ -54,7 +54,9 @@ def update_flow_attributes
         end
 
         def update_settings(t)
-          flow_input.settings&.each do |setting|
+          return if flow_input.settings.blank?
+
+          flow_input.settings.each do |setting|
             flow_setting = flow.flow_settings.find_or_initialize_by(flow_setting_id: setting.flow_setting_identifier)
             flow_setting.object = setting.value
 

db/migrate/20260121183311_allow_all_null_values_in_node_parameter.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class AllowAllNullValuesInNodeParameter < Code0::ZeroTrack::Database::Migration[1.0]
+  def change
+    add_check_constraint :node_parameters,
+                         '(num_nonnulls(literal_value, reference_value_id, function_value_id) <= 1)',
+                         name: check_constraint_name(:node_parameters, :value, :at_most_one)
+
+    remove_check_constraint :node_parameters,
+                            '(num_nonnulls(literal_value, reference_value_id, function_value_id) = 1)',
+                            name: check_constraint_name(:node_parameters, :value, :one_of)
+  end
+end

db/schema_migrations/20260121183311

@@ -0,0 +1 @@
+44b8e5e992817dec1f464949ee61b1c7937421aec377d3ee8d210ca06c2be9bc

db/structure.sql

@@ -596,7 +596,7 @@ CREATE TABLE node_parameters (
     created_at timestamp with time zone NOT NULL,
     updated_at timestamp with time zone NOT NULL,
     parameter_definition_id bigint NOT NULL,
-    CONSTRAINT check_fdac0ea550 CHECK ((num_nonnulls(literal_value, reference_value_id, function_value_id) = 1))
+    CONSTRAINT check_46b42221bc CHECK ((num_nonnulls(literal_value, reference_value_id, function_value_id) <= 1))
 );
 
 CREATE SEQUENCE node_parameters_id_seq

docs/graphql/input_object/nodeparameterinput.md

@@ -9,4 +9,4 @@ Input type for Node parameter
 | Name | Type | Description |
 |------|------|-------------|
 | `parameterDefinitionId` | [`ParameterDefinitionID!`](../scalar/parameterdefinitionid.md) | The identifier of the Parameter Definition |
-| `value` | [`NodeParameterValueInput`](../input_object/nodeparametervalueinput.md) | The value of the parameter |
+| `value` | [`NodeParameterValueInput!`](../input_object/nodeparametervalueinput.md) | The value of the parameter |

docs/graphql/object/literalvalue.md

@@ -8,7 +8,5 @@ Represents a literal value, such as a string or number.
 
 | Name | Type | Description |
 |------|------|-------------|
-| `createdAt` | [`Time!`](../scalar/time.md) | Time when this LiteralValue was created |
-| `updatedAt` | [`Time!`](../scalar/time.md) | Time when this LiteralValue was last updated |
-| `value` | [`JSON!`](../scalar/json.md) | The literal value itself as JSON. |
+| `value` | [`JSON`](../scalar/json.md) | The literal value itself as JSON. |
 

spec/models/node_parameter_spec.rb

@@ -28,8 +28,8 @@
     it 'validates only one of the value fields is present' do
       param = build(
         :node_parameter,
-        literal_value: nil,
-        reference_value: nil,
+        literal_value: 1,
+        reference_value: create(:reference_value),
         function_value: nil,
         parameter_definition: create(
           :parameter_definition,
@@ -41,7 +41,24 @@
       )
       expect(param).not_to be_valid
       expect(param.errors[:value])
-        .to include('Exactly one of literal_value, reference_value, or function_value must be present')
+        .to include('Only one of literal_value, reference_value, or function_value must be present')
+    end
+
+    it 'allows all values to be empty' do
+      param = build(
+        :node_parameter,
+        literal_value: nil,
+        reference_value: nil,
+        function_value: nil,
+        parameter_definition: create(
+          :parameter_definition,
+          data_type: create(
+            :data_type_identifier,
+            data_type: create(:data_type)
+          )
+        )
+      )
+      expect(param).to be_valid
     end
   end
 end