1 files changed, 38 insertions, 0 deletions
diff --git a/spec/models/concerns/ignorable_column_spec.rb b/spec/models/concerns/ignorable_column_spec.rb
new file mode 100644
index 00000000000..dba9fe43327
--- /dev/null
+++ b/spec/models/concerns/ignorable_column_spec.rb
@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+describe IgnorableColumn do
+  let :base_class do
+    Class.new do
+      def self.columns
+        # This method does not have access to "double"
+        [Struct.new(:name).new('id'), Struct.new(:name).new('title')]
+      end
+    end
+  end
+
+  let :model do
+    Class.new(base_class) do
+      include IgnorableColumn
+    end
+  end
+
+  describe '.columns' do
+    it 'returns the columns, excluding the ignored ones' do
+      model.ignore_column(:title)
+
+      expect(model.columns.map(&:name)).to eq(%w(id))
+    end
+  end
+
+  describe '.ignored_columns' do
+    it 'returns a Set' do
+      expect(model.ignored_columns).to be_an_instance_of(Set)
+    end
+
+    it 'returns the names of the ignored columns' do
+      model.ignore_column(:title)
+
+      expect(model.ignored_columns).to eq(Set.new(%w(title)))
+    end
+  end
+end