task(dossier): remove orphan champs

spec/lib/tasks/deployment/20220705164551_remove_unused_champs_spec.rb

@@ -0,0 +1,22 @@
+describe '20220705164551_remove_unused_champs' do
+  let(:rake_task) { Rake::Task['after_party:remove_unused_champs'] }
+  let(:procedure) { create(:procedure, :with_all_champs) }
+  let(:dossier) { create(:dossier, :with_populated_champs, procedure: procedure) }
+  let(:champ_repetition) { dossier.champs.find(&:repetition?) }
+
+  subject(:run_task) do
+    dossier
+    rake_task.invoke
+  end
+
+  before { champ_repetition.champs.first.update(type_de_champ: create(:type_de_champ)) }
+  after { rake_task.reenable }
+
+  describe 'remove_unused_champs' do
+    it "with bad champs" do
+      expect(Champ.where(dossier: dossier).count).to eq(39)
+      run_task
+      expect(Champ.where(dossier: dossier).count).to eq(38)
+    end
+  end
+end