Add interactor SetAccountPerson

app/interactors/set_account_person.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class SetAccountPerson
+  include Interactor
+
+  def call
+    context.account.update! person: context.person,
+                            contact_list: context.new_contact_list
+  end
+end

spec/interactors/set_account_person_spec.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe SetAccountPerson do
+  subject { described_class.call account: account, person: person }
+
+  let(:account) { create :usual_account, contact_list: old_contact_list }
+  let(:person) { create :initial_person, contact_list: new_contact_list }
+
+  let(:old_contact_list) { create :some_contact_list }
+  let(:new_contact_list) { create :some_contact_list }
+
+  specify do
+    expect { subject }.to \
+      change(account, :person)
+      .from(nil)
+      .to(person)
+  end
+
+  specify do
+    expect { subject }.to \
+      change(person, :account)
+      .from(nil)
+      .to(account)
+  end
+
+  specify do
+    expect { subject }.to \
+      change(account, :contact_list)
+      .from(old_contact_list)
+      .to(new_contact_list)
+  end
+
+  specify do
+    expect { subject }.not_to \
+      change(person, :contact_list)
+      .from(new_contact_list)
+  end
+
+  specify do
+    expect { subject }.not_to \
+      change(old_contact_list.contacts, :count)
+      .from(old_contact_list.contacts.count)
+  end
+
+  specify do
+    expect { subject }.not_to \
+      change(new_contact_list.contacts, :count)
+      .from(new_contact_list.contacts.count)
+  end
+
+  specify do
+    expect { subject }.not_to \
+      change(old_contact_list.contacts, :to_a)
+      .from(old_contact_list.contacts.to_a)
+  end
+
+  specify do
+    expect { subject }.not_to \
+      change(new_contact_list.contacts, :to_a)
+      .from(new_contact_list.contacts.to_a)
+  end
+end