Add rake task `db:obsolete_ignored_columns`

Show a list of obsolete `ignored_columns`

1 files changed, 43 insertions, 0 deletions

diff --git a/spec/lib/gitlab/database/obsolete_ignored_columns_spec.rb b/spec/lib/gitlab/database/obsolete_ignored_columns_spec.rb
new file mode 100644
index 00000000000..6d38f7f1b95
--- /dev/null
+++ b/spec/lib/gitlab/database/obsolete_ignored_columns_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Database::ObsoleteIgnoredColumns do
+  module Testing
+    class MyBase < ApplicationRecord
+    end
+
+    class SomeAbstract < MyBase
+      self.abstract_class = true
+
+      self.table_name = 'projects'
+
+      self.ignored_columns += %i[unused]
+    end
+
+    class B < MyBase
+      self.table_name = 'issues'
+
+      self.ignored_columns += %i[id other]
+    end
+
+    class A < SomeAbstract
+      self.ignored_columns += %i[id also_unused]
+    end
+
+    class C < MyBase
+      self.table_name = 'users'
+    end
+  end
+
+  subject { described_class.new(Testing::MyBase) }
+
+  describe '#execute' do
+    it 'returns a list of class names and columns pairs' do
+      expect(subject.execute).to eq([
+        ['Testing::A', %w(unused also_unused)],
+        ['Testing::B', %w(other)]
+      ])
+    end
+  end
+end