Added Cop to blacklist the use of serialize

This Cop blacklists the use of ActiveRecord's "serialize" method, except
for cases where we already use this.

1 files changed, 33 insertions, 0 deletions

diff --git a/spec/rubocop/cop/activerecord_serialize_spec.rb b/spec/rubocop/cop/activerecord_serialize_spec.rb
new file mode 100644
index 00000000000..a303b16d264
--- /dev/null
+++ b/spec/rubocop/cop/activerecord_serialize_spec.rb
@@ -0,0 +1,33 @@
+require 'spec_helper'
+require 'rubocop'
+require 'rubocop/rspec/support'
+require_relative '../../../rubocop/cop/activerecord_serialize'
+
+describe RuboCop::Cop::ActiverecordSerialize do
+  include CopHelper
+
+  subject(:cop) { described_class.new }
+
+  context 'inside the app/models directory' do
+    it 'registers an offense when serialize is used' do
+      allow(cop).to receive(:in_models?).and_return(true)
+
+      inspect_source(cop, 'serialize :foo')
+
+      aggregate_failures do
+        expect(cop.offenses.size).to eq(1)
+        expect(cop.offenses.map(&:line)).to eq([1])
+      end
+    end
+  end
+
+  context 'outside the app/models directory' do
+    it 'does nothing' do
+      allow(cop).to receive(:in_models?).and_return(false)
+
+      inspect_source(cop, 'serialize :foo')
+
+      expect(cop.offenses).to be_empty
+    end
+  end
+end