[#1421] Extract contents of both drop down lists

app/models/champs/linked_drop_down_list_champ.rb

@@ -1,2 +1,3 @@
 class Champs::LinkedDropDownListChamp < Champ
+  delegate :master_options, :slave_options, to: :type_de_champ
 end

app/models/types_de_champ/linked_drop_down_list_type_de_champ.rb

@@ -1,2 +1,31 @@
 class TypesDeChamp::LinkedDropDownListTypeDeChamp < TypeDeChamp
+  MASTER_PATTERN = /^--(.*)--$/
+
+  def master_options
+    master_options = unpack_options.map(&:first)
+    if master_options.present?
+      master_options.unshift('')
+    end
+    master_options
+  end
+
+  def slave_options
+    slave_options = unpack_options.to_h
+    if slave_options.present?
+      slave_options[''] = []
+    end
+    slave_options
+  end
+
+  private
+
+  def unpack_options
+    _, *options = drop_down_list.options
+    chunked = options.slice_before(MASTER_PATTERN)
+    chunked.map do |chunk|
+      master, *slave = chunk
+      slave.unshift('')
+      [MASTER_PATTERN.match(master)[1], slave]
+    end
+  end
 end

spec/models/types_de_champ/linked_drop_down_list_type_de_champ_spec.rb

@@ -0,0 +1,40 @@
+require 'spec_helper'
+
+describe TypesDeChamp::LinkedDropDownListTypeDeChamp do
+  describe '#unpack_options' do
+    let(:drop_down_list) { build(:drop_down_list, value: menu_options) }
+    let(:type_de_champ) { described_class.new(drop_down_list: drop_down_list) }
+
+    context 'with no options' do
+      let(:menu_options) { '' }
+      it { expect(type_de_champ.slave_options).to eq({}) }
+      it { expect(type_de_champ.master_options).to eq([]) }
+    end
+
+    context 'with two master options' do
+      let(:menu_options) do
+        <<~END_OPTIONS
+          --Master 1--
+          slave 1.1
+          slave 1.2
+          --Master 2--
+          slave 2.1
+          slave 2.2
+          slave 2.3
+        END_OPTIONS
+      end
+
+      it do
+        expect(type_de_champ.slave_options).to eq(
+          {
+            '' => [],
+            'Master 1' => [ '', 'slave 1.1', 'slave 1.2'],
+            'Master 2' => [ '', 'slave 2.1', 'slave 2.2', 'slave 2.3']
+          }
+        )
+      end
+
+      it { expect(type_de_champ.master_options).to eq([ '', 'Master 1', 'Master 2' ]) }
+    end
+  end
+end