VCR with placeholders

some_spec.rb

use_vcr_cassette 'some/cassette', :tag => :bad_staging_api

spec_helper.rb

VCR.configure do |c|
  c.cassette_library_dir = Rails.root.join('spec/fixtures/vcr_cassettes')
  c.hook_into :webmock
  c.default_cassette_options = { :record => :new_episodes }

  newly_recorded_bad_staging_api_request = lambda do |req|
    VCR.current_cassette &&
    VCR.current_cassette.tags.include?(:bad_staging_api) &&
    req.recordable?
  end

  # Needed for the 1st test run when the cassette is recorded, since the test
  # assumes the value is 836.00.
  c.after_http_request(newly_recorded_bad_staging_api_request) do |req, res|
    res.body.gsub!(/TotalRate\=["']([^"']+)["']/, %q{TotalRate="836.00"})
  end

  c.before_record(:bad_staging_api) do |interaction, cassette|
    interaction.response.body.gsub!(/TotalRate\=["']([^"']+)["']/, %q{TotalRate="<TOTAL_RATE>"})
  end

  # Needed for subsequent test runs...
  c.before_playback(:bad_staging_api) do |interaction|
    interaction.filter!('<TOTAL_RATE>', "836.00")
  end
end