Modules included by a context block doesn't take effect in another context block

modules_spec.rb

require 'spec_helper'

describe RSpec, 'module isolation' do
  module Example1
    def hoge
      "example1"
    end
  end
  module Example2
    def hoge
      "example2"
    end
  end

  context '#include Example1' do
    include Example1
    it 'should respond to :hoge and return "example1"' do
      expect(self).to respond_to(:hoge)
      expect(hoge).to eq("example1")
    end
  end
  context '#include Example2' do
    include Example2
    it 'should respond to :hoge and return "example2"' do
      expect(self).to respond_to(:hoge)
      expect(hoge).to eq("example2")
    end
  end
  context '#include nothing' do
    it 'should not respond to :hoge' do
      expect(self).not_to respond_to(:hoge)
    end
  end
end

describe RSpec do
  before { ExampleJob.perform_later }

  context '#include ActiveJob::TestHelper' do
    include ActiveJob::TestHelper

    it 'should be available to call #have_been_enqueued' do
      expect { expect(ExampleJob).to have_been_enqueued }.not_to raise_error
    end

    it 'should be available to call #assert_enqueued_jobs' do
      expect(self).to respond_to(:assert_enqueued_jobs)
      assert_enqueued_jobs 1
    end

    it 'should change queue_adapter to :test' do
      expect(ActiveJob::Base.queue_adapter).to be_kind_of(ActiveJob::QueueAdapters::TestAdapter)
    end
  end

  context 'not #include ActiveJob::TestHelper' do
    it 'should not be available to call #have_been_enqueued' do
      expect { expect(ExampleJob).to have_been_enqueued }.to raise_error(StandardError)
    end

    it 'should not be available to call #assert_enqueued_jobs' do
      expect(self).not_to respond_to(:assert_enqueued_jobs)
      expect{assert_enqueued_jobs(1)}.to raise_error(StandardError)
    end

    it 'should not change queue_adapter to :test' do
      expect(ActiveJob::Base.queue_adapter).not_to be_kind_of(ActiveJob::QueueAdapters::TestAdapter)
    end
  end
end

Background: I wanted to use ActiveJob::TestHelper only in some specific feature / context / describe block and I conducted a behavior test in such case that modules included in a specific context block and made sure that the modules doesn't take effect in the other context block in parallel.
Along with that, I determined that it is not needed to explicitly switch queue_adapter to :test if I include ActiveJob::TestHelper, as the module implicitly arranges queue_adapter for testing.

特定の spec でだけ ActiveJob::TestHelper を include して使いたかったので、特定の spec で include したモジュールが別の spec に影響を与えないことを確認する挙動テストを書いた。
また、 ActiveJob::TestHelper を include してしまえば明示的に queue_adapter を :test に切り替えなくても良いことを確認した。