🥗✨ Agreement: Test and implement the #create endpoint

- #1364

This is only for the classic HTML Request <=> Response Cycle. I realized
I probably want to do the `#index` Routes before `#create`, or at least
get started on the bits to expose adding an `Agreement` in the
`Spaces#edit` page.

app/controllers/space/agreements_controller.rb

@@ -1,11 +1,28 @@
 class Space
   class AgreementsController < ApplicationController
     def show
-      authorize(agreement)
+    end
+
+    def create
+      agreement.save
+
+      if agreement.errors.present?
+        render :new
+      else
+        redirect_to space.location(child: :agreements)
+      end
     end
 
     helper_method def agreement
-      @agreement ||= policy_scope(space.agreements).friendly.find(params[:id])
+      @agreement ||= if params[:id]
+        policy_scope(space.agreements).friendly.find(params[:id])
+      else
+        space.agreements.new(agreement_params)
+      end.tap { |agreement| authorize(agreement) }
+    end
+
+    def agreement_params
+      policy(Agreement).permit(params.require(:agreement))
     end
 
     def space

app/lib/space_routes.rb

@@ -1,6 +1,6 @@
 module SpaceRoutes
   def self.append_routes(router)
-    router.resources :agreements, only: %i[show], controller: "space/agreements"
+    router.resources :agreements, only: %i[show create], controller: "space/agreements"
     router.resource :authenticated_session, only: %i[new create update destroy show]
     router.resources :invitations, only: %i[create destroy index] do
       router.resource :rsvp, only: %i[show update]

app/policies/space/agreement_policy.rb

@@ -1,9 +1,19 @@
 class Space
   class AgreementPolicy < ApplicationPolicy
+    alias_method :agreement, :object
+
     def show?
       true
     end
 
+    def create?
+      person&.operator? || person&.member_of?(agreement.space)
+    end
+
+    def permitted_attributes(_)
+      %i[name body]
+    end
+
     class Scope < ::ApplicationScope
       def resolve
         scope.all

spec/requests/space/agreements_controller_request_spec.rb

@@ -1,15 +1,51 @@
 require "rails_helper"
 
 RSpec.describe Space::AgreementsController do
+  let(:space) { create(:space) }
+
   describe "#show" do
     subject(:perform_request) do
       get polymorphic_path([space, agreement])
       response
     end
 
-    let(:space) { agreement.space }
-    let(:agreement) { create(:space_agreement) }
+    let(:agreement) { create(:space_agreement, space: space) }
 
     it { is_expected.to render_template(:show) }
   end
+
+  describe "#create" do
+    subject(:perform_request) do
+      post polymorphic_path(space.location(child: :agreements)), params: {agreement: agreement_params}
+      response
+    end
+
+    let(:agreement_params) { attributes_for(:space_agreement) }
+
+    it { is_expected.to be_not_found }
+
+    context "when signed in as a member" do
+      before { sign_in(space, person) }
+
+      let(:person) { create(:membership, space: space).member }
+
+      specify do
+        perform_request
+        expect(space.reload.agreements).to exist(name: agreement_params[:name], body: agreement_params[:body])
+      end
+
+      it { is_expected.to redirect_to(space.location(child: :agreements)) }
+    end
+
+    context "when the agreement is invalid" do
+      before { sign_in(space, person) }
+
+      let(:person) { create(:membership, space: space).member }
+
+      let(:agreement_params) { attributes_for(:space_agreement, name: nil) }
+
+      it { is_expected.to render_template(:new) }
+      specify { expect { perform_request }.not_to change { space.agreements.reload.count } }
+    end
+  end
 end