fix: Forced variation not available in experiment (#292)

* fixes

* unit test  fix

* unit test added

* refactor

Author: ozayr-zaviar

lib/optimizely.rb

@@ -214,8 +214,8 @@ def decide(user_context, key, decide_options = [])
         experiment = decision.experiment
         rule_key = experiment ? experiment['key'] : nil
         variation = decision['variation']
-        variation_key = variation['key']
-        feature_enabled = variation['featureEnabled']
+        variation_key = variation ? variation['key'] : nil
+        feature_enabled = variation ? variation['featureEnabled'] : false
         decision_source = decision.source
       end
 
@@ -298,8 +298,17 @@ def decide_for_keys(user_context, keys, decide_options = [])
       decisions
     end
 
-    def get_flag_variation_by_key(flag_key, variation_key)
-      project_config.get_variation_from_flag(flag_key, variation_key)
+    # Gets variation using variation key or id and flag key.
+    #
+    # @param flag_key - flag key from which the variation is required.
+    # @param target_value - variation value either id or key that will be matched.
+    # @param attribute - string representing variation attribute.
+    #
+    # @return [variation]
+    # @return [nil] if no variation found in flag_variation_map.
+
+    def get_flag_variation(flag_key, target_value, attribute)
+      project_config.get_variation_from_flag(flag_key, target_value, attribute)
     end
 
     # Buckets visitor and sends impression event to Optimizely.
@@ -1098,11 +1107,11 @@ def send_impression(config, experiment, variation_key, flag_key, rule_key, enabl
       experiment_id = experiment['id']
       experiment_key = experiment['key']
 
-      if experiment_id != ''
-        variation_id = config.get_variation_id_from_key_by_experiment_id(experiment_id, variation_key)
-      else
-        varaition = get_flag_variation_by_key(flag_key, variation_key)
-        variation_id = varaition ? varaition['id'] : ''
+      variation_id = config.get_variation_id_from_key_by_experiment_id(experiment_id, variation_key) unless experiment_id.empty?
+
+      unless variation_id
+        variation = !flag_key.empty? ? get_flag_variation(flag_key, variation_key, 'key') : nil
+        variation_id = variation ? variation['id'] : ''
       end
 
       metadata = {

lib/optimizely/config/datafile_project_config.rb

@@ -302,9 +302,9 @@ def get_audience_from_id(audience_id)
       nil
     end
 
-    def get_variation_from_flag(flag_key, variation_key)
+    def get_variation_from_flag(flag_key, target_value, attribute)
       variations = @flag_variation_map[flag_key]
-      return variations.select { |variation| variation['key'] == variation_key }.first if variations
+      return variations.select { |variation| variation[attribute] == target_value }.first if variations
 
       nil
     end

lib/optimizely/decision_service.rb

@@ -193,6 +193,7 @@ def get_variation_for_feature_experiment(project_config, feature_flag, user_cont
         next unless variation_id
 
         variation = project_config.get_variation_from_id_by_experiment_id(experiment_id, variation_id)
+        variation = project_config.get_variation_from_flag(feature_flag['key'], variation_id, 'id') if variation.nil?
 
         return Decision.new(experiment, variation, DECISION_SOURCES['FEATURE_TEST']), decide_reasons
       end

lib/optimizely/optimizely_user_context.rb

@@ -164,7 +164,7 @@ def find_validated_forced_decision(context)
       reasons = []
       target = rule_key ? "flag (#{flag_key}), rule (#{rule_key})" : "flag (#{flag_key})"
       if variation_key
-        variation = @optimizely_client.get_flag_variation_by_key(flag_key, variation_key)
+        variation = @optimizely_client.get_flag_variation(flag_key, variation_key, 'key')
         if variation
           reason = "Variation (#{variation_key}) is mapped to #{target} and user (#{@user_id}) in the forced decision map."
           reasons.push(reason)

spec/optimizely_user_context_spec.rb

@@ -284,6 +284,29 @@
       expect(decision.reasons).to eq(['Variation (b) is mapped to flag (feature_1), rule (exp_with_audience) and user (tester) in the forced decision map.'])
     end
 
+    it 'should return an expected decision object when forced decision is called and variation of different experiment but same flag key' do
+      user_id = 'tester'
+      feature_key = 'feature_1'
+      original_attributes = {}
+      user_context_obj = Optimizely::OptimizelyUserContext.new(forced_decision_project_instance, user_id, original_attributes)
+      context = Optimizely::OptimizelyUserContext::OptimizelyDecisionContext.new(feature_key, 'exp_with_audience')
+      forced_decision = Optimizely::OptimizelyUserContext::OptimizelyForcedDecision.new('3324490633')
+      user_context_obj.set_forced_decision(context, forced_decision)
+      expected = expect do
+        decision = user_context_obj.decide(feature_key, [Optimizely::Decide::OptimizelyDecideOption::INCLUDE_REASONS])
+        expect(decision.variation_key).to eq('3324490633')
+        expect(decision.rule_key).to eq('exp_with_audience')
+        expect(decision.enabled).to be false
+        expect(decision.flag_key).to eq(feature_key)
+        expect(decision.user_context.user_id).to eq(user_id)
+        expect(decision.user_context.user_attributes.length).to eq(0)
+        expect(decision.user_context.forced_decisions.length).to eq(1)
+        expect(decision.user_context.forced_decisions).to eq(context => forced_decision)
+        expect(decision.reasons).to eq(['Variation (3324490633) is mapped to flag (feature_1), rule (exp_with_audience) and user (tester) in the forced decision map.'])
+      end
+      expected.to raise_error
+    end
+
     it 'should return correct variation if rule in forced decision is deleted' do
       impression_log_url = 'https://logx.optimizely.com/v1/events'
       time_now = Time.now