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Add Timecop cop
This cop makes `Timecop` illegal, in favour of `ActiveSupport::Testing::TimeHelpers`. Specifically, - `Timecop.freeze` should be replaced with `freeze_time` (autocorrected) - `Timecop.freeze(...)` should be replaced with `travel` or `travel_to` - `Timecop.return` should be replaced with `travel_back` (autocorrected) - `Timecop.travel` should be replaced with `travel` or `travel_to`. - Explicitly travelling again should be used instead of relying on time continuing to flow - `Timecop` should not appear anywhere
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‎lib/rubocop/cop/rails/timecop.rb

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# frozen_string_literal: true
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module RuboCop
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module Cop
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module Rails
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class Timecop < Cop
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FREEZE_MESSAGE = 'Use `freeze_time` instead of `Timecop.freeze`'
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FREEZE_WITH_ARGUMENTS_MESSAGE = 'Use `travel` or `travel_to` instead of `Timecop.freeze`'
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RETURN_MESSAGE = 'Use `travel_back` instead of `Timecop.return`'
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TRAVEL_MESSAGE = 'Use `travel` or `travel_to` instead of `Timecop.travel`. If you need time to keep flowing, ' \
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'simulate it by travelling again.'
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MSG = 'Use `ActiveSupport::Testing::TimeHelpers` instead of `Timecop`'
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FREEZE_TIME = 'freeze_time'
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TRAVEL_BACK = 'travel_back'
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TIMECOP_PATTERN_STRING = <<~PATTERN
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(const {nil? (:cbase)} :Timecop)
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PATTERN
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def_node_matcher :timecop, TIMECOP_PATTERN_STRING
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def_node_matcher :timecop_send, <<~PATTERN
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(send
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#{TIMECOP_PATTERN_STRING} ${:freeze :return :travel}
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$...
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)
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PATTERN
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def on_const(node)
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return unless timecop(node)
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timecop_send(node.parent) do |message, arguments|
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return on_timecop_send(node.parent, message, arguments)
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end
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add_offense(node)
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end
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def autocorrect(node)
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lambda do |corrector|
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timecop_send(node) do |message, arguments|
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case message
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when :freeze
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autocorrect_freeze(corrector, node, arguments)
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when :return
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autocorrect_return(corrector, node, arguments)
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end
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end
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end
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end
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private
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def on_timecop_send(node, message, arguments)
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case message
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when :freeze
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on_timecop_freeze(node, arguments)
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when :return
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on_timecop_return(node, arguments)
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when :travel
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on_timecop_travel(node, arguments)
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else
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add_offense(node)
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end
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end
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def on_timecop_freeze(node, arguments)
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if arguments.empty?
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add_offense(node, message: FREEZE_MESSAGE)
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else
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add_offense(node, message: FREEZE_WITH_ARGUMENTS_MESSAGE)
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end
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end
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def on_timecop_return(node, _arguments)
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add_offense(node, message: RETURN_MESSAGE)
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end
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def on_timecop_travel(node, _arguments)
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add_offense(node, message: TRAVEL_MESSAGE)
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end
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def autocorrect_freeze(corrector, node, arguments)
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return unless arguments.empty?
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corrector.replace(receiver_and_message_range(node), FREEZE_TIME)
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end
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def autocorrect_return(corrector, node, _arguments)
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corrector.replace(receiver_and_message_range(node), TRAVEL_BACK)
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end
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def receiver_and_message_range(node)
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# FIXME: There is probably a better way to do this
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# Just trying to get the range of `Timecop.method_name`, without args, or block, or anything
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node.location.expression.with(end_pos: node.location.selector.end_pos)
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end
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end
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end
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end
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end

‎lib/rubocop/cop/rails_cops.rb

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require_relative 'rails/scope_args'
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require_relative 'rails/skips_model_validations'
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require_relative 'rails/time_zone'
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require_relative 'rails/timecop'
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require_relative 'rails/uniq_before_pluck'
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require_relative 'rails/unknown_env'
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require_relative 'rails/validation'

‎spec/rubocop/cop/rails/timecop_spec.rb

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# frozen_string_literal: true
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RSpec.describe(RuboCop::Cop::Rails::Timecop, :config) do
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subject(:cop) { described_class.new(config) }
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describe 'Timecop.freeze' do
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context 'without a block' do
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context 'without arguments' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.freeze
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^^^^^^^^^^^^^^ Use `freeze_time` instead of `Timecop.freeze`
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RUBY
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end
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it 'autocorrects to `freeze_time`' do
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expect(autocorrect_source('Timecop.freeze')).to(eq('freeze_time'))
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end
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end
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context 'with arguments' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.freeze(123)
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^^^^^^^^^^^^^^^^^^^ Use `travel` or `travel_to` instead of `Timecop.freeze`
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RUBY
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end
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it 'does not autocorrect' do
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source = 'Timecop.freeze(123)'
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expect(autocorrect_source(source)).to(eq(source))
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end
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end
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end
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context 'with a block' do
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context 'without arguments' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.freeze { }
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^^^^^^^^^^^^^^ Use `freeze_time` instead of `Timecop.freeze`
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RUBY
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end
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it 'autocorrects to `freeze_time`' do
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expect(autocorrect_source('Timecop.freeze { }')).to(eq('freeze_time { }'))
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end
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end
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context 'with arguments' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.freeze(123) { }
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^^^^^^^^^^^^^^^^^^^ Use `travel` or `travel_to` instead of `Timecop.freeze`
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RUBY
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end
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# FIXME: Is this how NOT autocorrecting something should be tested?
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it 'does not autocorrect' do
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source = 'Timecop.freeze(123) { }'
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expect(autocorrect_source(source)).to(eq(source))
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end
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end
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end
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end
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describe 'Timecop.return' do
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context 'without a block' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.return
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^^^^^^^^^^^^^^ Use `travel_back` instead of `Timecop.return`
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RUBY
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end
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it 'autocorrects to `travel_back`' do
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expect(autocorrect_source('Timecop.return')).to(eq('travel_back'))
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end
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end
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context 'with a block' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.return { }
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^^^^^^^^^^^^^^ Use `travel_back` instead of `Timecop.return`
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RUBY
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end
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it 'autocorrects to `travel_back`' do
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expect(autocorrect_source('Timecop.return { }')).to(eq('travel_back { }'))
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end
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end
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end
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describe 'Timecop.travel' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.travel(123) { }
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^^^^^^^^^^^^^^^^^^^ Use `travel` or `travel_to` instead of `Timecop.travel`. If you need time to keep flowing, simulate it by travelling again.
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RUBY
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end
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end
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describe 'Timecop.*' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.foo
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^^^^^^^ Use `ActiveSupport::Testing::TimeHelpers` instead of `Timecop`
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RUBY
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end
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end
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describe 'Timecop' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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Timecop.foo
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^^^^^^^ Use `ActiveSupport::Testing::TimeHelpers` instead of `Timecop`
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RUBY
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end
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end
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describe '::Timecop' do
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it 'adds an offense' do
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expect_offense(<<~RUBY)
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::Timecop.foo
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^^^^^^^^^ Use `ActiveSupport::Testing::TimeHelpers` instead of `Timecop`
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RUBY
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end
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end
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end

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