#431

backend/spec/models/tag_group_spec.rb

@@ -20,4 +20,33 @@ RSpec.describe TagGroup, type: :model do
         .to include('id' => group.id, 'name' => 'history owner', 'members' => [])
   end
 
+  it 'destroys a group with nested placements and child membership, retaining history' do
+    child = create_group(name: 'child group')
+
+    parent = create_group(
+        name: 'parent group',
+        members: [{ 'tag_group_id' => child.id }],
+        placements: [{
+            'section_name' => 'section',
+            'description' => nil,
+            'children' => [{
+                'tag_group_id' => child.id,
+                'children' => []
+            }]
+        }])
+
+    versions = parent.versions.order(:version_no).map(&:attributes)
+
+    expect { parent.destroy! }
+        .to change(TagGroup, :count).by(-1)
+        .and change(TagGroupVersion, :count).by(0)
+
+    expect(TagGroupVersion.where(tag_group_id: parent.id)
+        .order(:version_no).map(&:attributes)).to eq(versions)
+
+    expect(child.reload).to be_persisted
+    expect(TagGroupPlacement.where(tag_group_id: parent.id)).to be_empty
+    expect(TagGroupTag.where(tag_group_id: parent.id)).to be_empty
+    expect(TagGroupGroup.where(tag_group_id: parent.id)).to be_empty
+  end
 end