Support individual exemption deregistration

Gemfile.lock

@@ -66,7 +66,7 @@ GEM
     ast (2.4.0)
     aws-eventstream (1.0.2)
     aws-partitions (1.144.0)
-    aws-sdk-core (3.48.0)
+    aws-sdk-core (3.48.1)
       aws-eventstream (~> 1.0, >= 1.0.2)
       aws-partitions (~> 1.0)
       aws-sigv4 (~> 1.1)
@@ -117,7 +117,7 @@ GEM
       railties (>= 3.2, < 6.1)
     erubis (2.7.0)
     execjs (2.7.0)
-    factory_bot (5.0.0)
+    factory_bot (5.0.2)
       activesupport (>= 4.2.0)
     factory_bot_rails (5.0.1)
       factory_bot (~> 5.0.0)

app/assets/stylesheets/application.scss

@@ -37,6 +37,7 @@
 @import 'partials/dashboard';
 @import 'partials/dates';
 @import 'partials/footer';
+@import 'partials/input';
 @import 'partials/pagination';
 @import 'partials/people';
 @import 'partials/resource_details';

app/assets/stylesheets/partials/_input.scss

@@ -0,0 +1,38 @@
+// Reset all input widths to default
+input.form-control {
+  width: 100%
+}
+
+// Following styles taken from https://github.com/alphagov/govuk-frontend/blob/master/src/components/input/_input.scss
+
+// The ex measurements are based on the number of W's that can fit inside the input
+// Extra space is left on the right hand side to allow for the Safari prefill icon
+// Linear regression estimation based on visual tests: y = 1.76 + 1.81x
+
+.govuk-input--width-30 {
+  max-width: 56ex + 3ex;
+}
+
+.govuk-input--width-20 {
+  max-width: 38ex + 3ex;
+}
+
+.govuk-input--width-10 {
+  max-width: 20ex + 3ex;
+}
+
+.govuk-input--width-5 {
+  max-width: 10.8ex;
+}
+
+.govuk-input--width-4 {
+  max-width: 9ex;
+}
+
+.govuk-input--width-3 {
+  max-width: 7.2ex;
+}
+
+.govuk-input--width-2 {
+  max-width: 5.4ex;
+}

app/models/concerns/waste_exemptions_engine/can_deactivate_exemption.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module WasteExemptionsEngine
+  module CanDeactivateExemption
+    extend ActiveSupport::Concern
+
+    included do
+      include AASM
+
+      aasm column: :state do
+        state :active
+        state :ceased
+        state :expired
+        state :revoked
+
+        event :cease do
+          transitions from: :active,
+                      to: :ceased
+        end
+
+        event :revoke do
+          transitions from: :active,
+                      to: :revoked
+        end
+
+        event :expire do
+          transitions from: :active,
+                      to: :expired
+        end
+      end
+    end
+  end
+end

app/models/waste_exemptions_engine/registration_exemption.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+require WasteExemptionsEngine::Engine.root.join("app", "models", "waste_exemptions_engine", "registration_Exemption")
+
+module WasteExemptionsEngine
+  class RegistrationExemption
+    include CanDeactivateExemption
+  end
+end

spec/models/registration_exemption_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe WasteExemptionsEngine::RegistrationExemption, type: :model do
+  subject(:registration_exemption) { build(:registration).registration_exemptions.first }
+  let(:permitted_states) { registration_exemption.aasm.states(permitted: true).map(&:name) }
+
+  transitions = %i[cease revoke expire]
+  inactive_states = %i[ceased revoked expired]
+
+  describe "exemption state" do
+    context "when the state is 'active'" do
+      before(:each) { registration_exemption.state = :active }
+
+      it "can transition to any of the inactive states" do
+        expect(permitted_states).to match_array(inactive_states)
+      end
+
+      transitions.zip(inactive_states).each do |tansition, expected_state|
+        context "and the '#{tansition}' transition is executed" do
+          it "reflects the correct state" do
+            expect { registration_exemption.send("#{tansition}!") }
+              .to change { registration_exemption.state }
+              .from("active")
+              .to(expected_state.to_s)
+          end
+        end
+      end
+    end
+
+    inactive_states.each do |inactive_state|
+      context "when the state is #{inactive_state}" do
+        before(:each) { registration_exemption.state = inactive_state }
+        it "can not transition to any other status" do
+          expect(permitted_states).to be_empty
+        end
+      end
+    end
+  end
+end