Flags with prerequisites `check_variation_range` compares the range for the flag's variations instead of the prerequisite's flag variations.

[JoSuzuki]

Describe the bug
When starting an app with the launchdarkly-server-sdk I get the following error:

I, [2024-03-20T13:20:56.879571 #2115]  INFO -- : [LDClient] Initializing stream connection
I, [2024-03-20T13:20:56.883992 #2115]  INFO -- : Connecting to event stream at https://stream.launchdarkly.com/all
E, [2024-03-20T13:20:57.472795 #2115] ERROR -- : [LDClient] Data inconsistency in feature flag "feature_flag_B": prerequisite has invalid variation index
I, [2024-03-20T13:20:57.479488 #2115]  INFO -- : [LDClient] Stream initialized

feature_flag_B has a prerequisite feature_flag_A on variation 2 (live)
feature_flag_A has 4 variations [off , onboarding, live, offboarding]

To reproduce

• Create feature_flag_A with 4 variations
• Create feature_flag_B with two variations
• Make feature_flag_A with variation of index 2 a prerequisite of feature_flag_B
• When starting the app with those feature flags the error will appear as ERROR -- : [LDClient] Data inconsistency in feature flag "feature_flag_B": prerequisite has invalid variation index.

Expected behavior
When starting the app no error is logged.

SDK version
7.2.0

Language version, developer tools
ruby 3.2.2

OS/platform
Ubuntu 22.04

Additional context
I believe the code path followed to get the error is:
When creating the feature_flag_B at

ruby-server-sdk/lib/ldclient-rb/impl/model/feature_flag.rb

Line 40 in 389953b

Prerequisite.new(prereq_data, self, errors)

There will be a prerequisite {:key=>"feature_flag_A", :variation=>2}, which will create a Prerequisite

ruby-server-sdk/lib/ldclient-rb/impl/model/feature_flag.rb

Lines 120 to 128 in 389953b

	class Prerequisite
	def initialize(data, flag, errors_out = nil)
	@data = data
	@key = data[:key]
	@variation = data[:variation]
	@failure_result = EvaluatorHelpers.evaluation_detail_for_off_variation(flag,
	EvaluationReason::prerequisite_failed(@key))
	check_variation_range(flag, errors_out, @variation, "prerequisite")
	end

and call check_variation_range

ruby-server-sdk/lib/ldclient-rb/impl/model/feature_flag.rb

Lines 7 to 13 in 389953b

	def check_variation_range(flag, errors_out, variation, description)
	unless flag.nil? || errors_out.nil? || variation.nil?
	if variation < 0 || variation >= flag.variations.length
	errors_out << "#{description} has invalid variation index"
	end
	end
	end

Which compares the feature_flag_B.variations.length with feature_flag_A prerequisite variation 2. I believe the intended action would be to compare the feature_flag_A.variations.length instead.

[keelerm84]

Sorry for the delay on this. This has been fixed in 7.3.3

[JoSuzuki]

Sorry for the delay on this. This has been fixed in 7.3.3

Thank you!