Rspec, VCR custom request matchers to ignore nondeterministic params

vcr_config_and_example.rb

#In your rails_helper.rb
some_api_matcher = VCR.request_matchers.uri_without_param(:token)

VCR.configure do |config|
  # use the following option to debug VCR
  # config.debug_logger = STDOUT
  config.cassette_library_dir = "spec/cassettes"
  config.hook_into :webmock, :typhoeus, :faraday
  config.default_cassette_options = { record: :new_episodes }
  config.allow_http_connections_when_no_cassette = false
  config.register_request_matcher :no_random_token, &some_api_matcher
end

#In your test
require "rails_helper"

feature "Filling in a form that calls an api with nondeterministic params", :feature do
  describe "The form" do
  it "should autopopulate the fields from the api" do
      VCR.use_cassette "features/api_form",
                        match_requests_on:
                        [:method, :no_random_token] do
        visit forms_path
        fill_in "person_form_id_field", with: "123456"
        click_on "Call API to Get Form"
        api_form_value = find_field("some_value[value_name]").value
        expect(api_form_value).to eq("This is data from an api with a crazy random token")
        
        #this calls another api but VCR can handle that in 1 cassette
        click_on "Submit form"
        visit forms_path
        click_on "PDF output of the form"
        #now we know the processing of second apis response worked
        expect(page.body[1..3]).to eq("PDF") #crude, but its a pdf
      end
    end
  end
end