Fix behavior for missing attributes in submit/assign_form_params: set the attribute to its default value or nil

Author: Intrepidd

lib/hyper_active_form/base.rb

@@ -28,7 +28,8 @@ def perform
     def assign_form_attributes(params)
       params = ActionController::Parameters.new(params) unless params.is_a?(ActionController::Parameters)
       attribute_names.each do |attribute|
-        public_send(:"#{attribute}=", params&.dig(attribute)) if params&.key?(attribute)
+        default_value = self.class._default_attributes[attribute]&.value_before_type_cast
+        public_send(:"#{attribute}=", params&.dig(attribute) || default_value)
       end
     end
 

spec/hyper_active_form/base_spec.rb

@@ -12,6 +12,7 @@ def self.model_name
     Class.new(HyperActiveForm::Base) do
       attribute :name
       attribute :age
+      attribute :hobbies, default: []
 
       def self.model_name
         ActiveModel::Name.new(self, nil, "Dummy")
@@ -42,6 +43,16 @@ def perform
     end
   end
 
+  describe "#assign_form_attributes" do
+    it "assigns attributes from params or defaults or nil" do
+      form = dummy_class.new(name: "John", age: 20)
+      form.assign_form_attributes(name: "Mike")
+      expect(form.name).to eq("Mike")
+      expect(form.age).to eq(nil)
+      expect(form.hobbies).to eq([])
+    end
+  end
+
   describe "#submit" do
     context "when the form is valid" do
       it "returns true and performs the form" do