refactor CreateGameNight to scope to create join table

app/controllers/game_nights_controller.rb

@@ -1,6 +1,7 @@
 class GameNightsController < AuthenticationController
   def create
-    result = CreateGameNight.call(game_night_params: game_night_params)
+    result = CreateGameNight.call(user:              current_user,
+                                  game_night_params: game_night_params)
 
     if result.success?
       render json: result.game_night, status: :created
@@ -10,7 +11,8 @@ def create
   end
 
   def update
-    result = UpdateGameNight.call(id: params[:id], game_night_params: game_night_params)
+    result = UpdateGameNight.call(id:                params[:id],
+                                  game_night_params: game_night_params)
 
     if result.success?
       render json: result.game_night, status: :ok

app/interactors/create_game_night.rb

@@ -1,10 +1,10 @@
 class CreateGameNight < StandardInteraction
   def validate_input
-    context.fail!(errors: "invalid input") unless context.game_night_params
+    context.fail!(errors: "invalid input") unless valid_input?
   end
 
   def execute
-    context.game_night = GameNight.create(context.game_night_params)
+    context.game_night = create_game_night
   end
 
   def validate_output
@@ -16,4 +16,12 @@ def validate_output
   def game_night_saved?
     context.game_night.persisted?
   end
+
+  def valid_input?
+    context.game_night_params && context.user
+  end
+
+  def create_game_night
+    context.user.game_nights.create(context.game_night_params)
+  end
 end

app/interactors/delete_game_night.rb

@@ -8,6 +8,12 @@ def execute
   end
 
   def validate_output
-    context.fail!(errors: "game night not deleted") unless context.game_night.destroyed?
+    context.fail!(errors: "game night not deleted") unless game_night_destroyed?
+  end
+
+  private
+
+  def game_night_destroyed?
+    context.game_night.destroyed?
   end
 end

spec/controllers/game_nights_controller_spec.rb

@@ -12,11 +12,13 @@
     end
 
     let(:create_game_night_input) do
-      { game_night_params: {
-        name:             game_night.name,
-        time:             game_night.time,
-        location_name:    game_night.location_name,
-        location_address: game_night.location_address }
+      {
+        user:              user,
+        game_night_params: {
+          name:             game_night.name,
+          time:             game_night.time,
+          location_name:    game_night.location_name,
+          location_address: game_night.location_address }
       }
     end
 
@@ -73,11 +75,13 @@
     end
 
     let(:update_game_night_input) do
-      { game_night_params: {
-        name:             game_night.name,
-        time:             game_night.time,
-        location_name:    game_night.location_name,
-        location_address: game_night.location_address }
+      {
+        id:                game_night.id.to_s,
+        game_night_params: {
+          name:             game_night.name,
+          time:             game_night.time,
+          location_name:    game_night.location_name,
+          location_address: game_night.location_address }
       }
     end
 

spec/interactors/create_game_night_spec.rb

@@ -1,16 +1,18 @@
 RSpec.describe CreateGameNight do
   describe ".call" do
+    let(:user) { create(:confirmed_user) }
+
     let(:game_night_params) do
       {
-        time:             DateTime.new(2016, 1, 22, 16, 02, 00),
+        time:             DateTime.new.utc,
         name:             "Space Hulk Tournament",
         location_name:    "The library",
         location_address: "123 fake st"
       }
     end
 
     subject do
-      described_class.call(game_night_params: game_night_params)
+      described_class.call(user: user, game_night_params: game_night_params)
     end
 
     context "when successful" do
@@ -37,7 +39,7 @@
       end
     end
 
-    context "when invalid input is provided" do
+    context "when params not provided" do
       subject do
         described_class.call(game_night_params: nil)
       end
@@ -50,5 +52,19 @@
         expect(subject.errors).to eq("invalid input")
       end
     end
+
+    context "when user not provided" do
+      subject do
+        described_class.call(game_night_params: game_night_params)
+      end
+
+      it "fails" do
+        is_expected.to be_a_failure
+      end
+
+      it "returns an error" do
+        expect(subject.errors).to eq("invalid input")
+      end
+    end
   end
 end

spec/interactors/delete_game_night_spec.rb

@@ -32,7 +32,8 @@
 
     context "when destroy fails" do
       before do
-        allow_any_instance_of(GameNight).to receive(:destroyed?).and_return(false)
+        allow_any_instance_of(GameNight).to receive(:destroyed?).
+          and_return(false)
       end
 
       subject do

spec/interactors/update_game_night_spec.rb

@@ -4,7 +4,7 @@
 
     let(:game_night_params) do
       {
-        time:             DateTime.new(2016, 1, 22, 16, 02, 00),
+        time:             DateTime.new.utc,
         name:             "Space Hulk Tournament",
         location_name:    "The library",
         location_address: "123 fake st"
@@ -13,7 +13,8 @@
 
     context "when successful" do
       subject do
-        described_class.call(id: game_night.id, game_night_params: game_night_params)
+        described_class.call(id:                game_night.id,
+                             game_night_params: game_night_params)
       end
 
       it "returns a successful context" do
@@ -55,7 +56,8 @@
       end
 
       subject do
-        described_class.call(id: game_night.id, game_night_params: game_night_params)
+        described_class.call(id:                game_night.id,
+                             game_night_params: game_night_params)
       end
 
       it "fails" do