Describe the bug

Using the flag_overrides parameter on v6+ of this gem causes an error:

NoMethodError (undefined method `create_data_source' for #<ConfigCat::LocalDictionaryDataSource:0x00000001135fd020 @_override_behaviour=0, 
# removed our configuration details ...

      @_override_data_source = options.flag_overrides.create_data_source(@log)
                                                        ^^^^^^^^^^^^^^^^^^^):

To reproduce

Initialise a config cat client with the flag_overrides parameter set.

Failing spec: #26

Expected behavior

This used to override local feature flags when using offline settings. E.g:

flag_overrides = LocalDictionaryDataSource.new(
      { some_feature: "yes" },
      OverrideBehaviour::LOCAL_ONLY,
    )
    client = ConfigCatClient.get("test", ConfigCatOptions.new(flag_overrides: flag_overrides))

Describe the bug

Can't seem to override config in testing my rails app. I have webmock set-up to mock external HTTP calls and I did need to mock the configcat request to get my tests running initially.

To reproduce

As per suggestion in docs, I created a Singleton via an initializer:

# config/initializers/configcat.rb
require 'configcat'
require 'singleton'

class FeatureFlagConfig
  include Singleton
  def initialize
    @client = ConfigCat.create_client(ENV["CONFIGCAT_KEY"])
  end

  def get_value(flag)
  	@client.get_value(flag, false)
  end

  def refresh
    @client.force_refresh
  end
end

i create a stub as per webmock

require 'webmock'
include WebMock::API

def stub_configcat_config
	stub_request(
		:get, 
		"https://cdn-global.configcat.com/configuration-files/#{ENV['CONFIGCAT_KEY']}/config_v5.json"
	).to_return(
		status: 200,
		body: {
		  "f": {
		    "my_feature": {
		      "v": false,
		    }
		  }
		}.to_json
	)
end

within my rails_helper.rb, I add a before hook

  config.before(:each, type: :request) do
    WebMock.disable_net_connect!(allow: '127.0.0.1')
    stub_configcat_config
    FeatureFlagConfig.instance.refresh
puts FeatureFlagConfig.instance.get_value('my_feature')
  end

If i now run 15 or 20 specs, while it's running, toggle the feature flag. It will show the returned value change from true to false (or V.V.) during the run.

Expected behavior

I expected the value I provided in my http mock_request to pverride the result. I guess somehow the caching is bypassing webmock. I anticipate this would cause problems in CI. I also want to avoid using a different Client / caching strategy for the test environment

Screenshots

bundle exec rspec spec/requests/
{"my_feature"=>false}
.{"my_feature"=>false}
.{"my_feature"=>false}
.{"my_feature"=>false}
.{"my_feature"=>false}
.{"my_feature"=>false}
.{"my_feature"=>false}
.*{"my_feature"=>true}
F{"my_feature"=>true}
.{"my_feature"=>true}
.{"my_feature"=>true}
F{"my_feature"=>true}
.**{"my_feature"=>true}
F{"my_feature"=>true}
.{"my_feature"=>true}