Add a cop to detect usages of Timecop.freeze

.rubocop.yml

@@ -282,6 +282,14 @@ Cop/ActiveRecordAssociationReload:
 Gitlab/AvoidFeatureGet:
   Enabled: true
 
+RSpec/TimecopFreeze:
+  Enabled: false
+  AutoCorrect: true
+  Include:
+    - 'spec/**/*.rb'
+    - 'ee/spec/**/*.rb'
+    - 'qa/spec/**/*.rb'
+
 Naming/PredicateName:
   Enabled: true
   Exclude:

rubocop/cop/rspec/timecop_freeze.rb

+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      # This cop checks for `Timecop.freeze` usage in specs.
+      #
+      # @example
+      #
+      #   # bad
+      #   Timecop.freeze(Time.current) { example.run }
+      #
+      #   # good
+      #   freeze_time(Time.current) { example.run }
+      #
+      class TimecopFreeze < RuboCop::Cop::Cop
+        include MatchRange
+        MESSAGE = 'Do not use `Timecop.freeze`, use `freeze_time` instead. ' \
+                  'See https://gitlab.com/gitlab-org/gitlab/-/issues/214432 for more info.'
+
+        def_node_matcher :timecop_freeze?, <<~PATTERN
+          (send (const nil? :Timecop) :freeze ?_)
+        PATTERN
+
+        def on_send(node)
+          return unless timecop_freeze?(node)
+
+          add_offense(node, location: :expression, message: MESSAGE)
+        end
+
+        def autocorrect(node)
+          -> (corrector) do
+            each_match_range(node.source_range, /^(Timecop\.freeze)/) do |match_range|
+              corrector.replace(match_range, 'freeze_time')
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/rspec/timecop_freeze_spec.rb

+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+
+require_relative '../../../../rubocop/cop/rspec/timecop_freeze'
+
+RSpec.describe RuboCop::Cop::RSpec::TimecopFreeze, type: :rubocop do
+  include CopHelper
+
+  subject(:cop) { described_class.new }
+
+  context 'when calling Timecop.freeze' do
+    let(:source) do
+      <<~SRC
+      Timecop.freeze(Time.current) { example.run }
+      SRC
+    end
+
+    let(:corrected_source) do
+      <<~SRC
+      freeze_time(Time.current) { example.run }
+      SRC
+    end
+
+    it 'registers an offence' do
+      inspect_source(source)
+
+      expect(cop.offenses.size).to eq(1)
+    end
+
+    it 'can autocorrect the source' do
+      expect(autocorrect_source(source)).to eq(corrected_source)
+    end
+  end
+
+  context 'when calling a different method on Timecop' do
+    let(:source) do
+      <<~SRC
+      Timecop.travel(Time.current)
+      SRC
+    end
+
+    it 'does not register an offence' do
+      inspect_source(source)
+
+      expect(cop.offenses).to be_empty
+    end
+  end
+end