Check nil to prevent panic. (#162)

Author: Mike Davis

pkg/client/client.go

@@ -96,7 +96,7 @@ func (o *OptimizelyClient) IsFeatureEnabled(featureKey string, userContext entit
 		}
 	}()
 
-	context, featureDecision, err := o.getFeatureDecision(featureKey, userContext)
+	decisionContext, featureDecision, err := o.getFeatureDecision(featureKey, userContext)
 	if err != nil {
 		logger.Error("received an error while computing feature decision", err)
 		return result, err
@@ -116,7 +116,7 @@ func (o *OptimizelyClient) IsFeatureEnabled(featureKey string, userContext entit
 
 	if featureDecision.Source == decision.FeatureTest {
 		// send impression event for feature tests
-		impressionEvent := event.CreateImpressionUserEvent(context.ProjectConfig, featureDecision.Experiment, *featureDecision.Variation, userContext)
+		impressionEvent := event.CreateImpressionUserEvent(decisionContext.ProjectConfig, featureDecision.Experiment, *featureDecision.Variation, userContext)
 		o.EventProcessor.ProcessEvent(impressionEvent)
 	}
 	return result, err
@@ -214,12 +214,12 @@ func (o *OptimizelyClient) GetFeatureVariableString(featureKey, variableKey stri
 // GetFeatureVariable returns feature as a string along with it's associated type
 func (o *OptimizelyClient) GetFeatureVariable(featureKey, variableKey string, userContext entities.UserContext) (value string, valueType entities.VariableType, err error) {
 
-	context, featureDecision, err := o.getFeatureDecision(featureKey, userContext)
+	decisionContext, featureDecision, err := o.getFeatureDecision(featureKey, userContext)
 	if err != nil {
 		return "", "", err
 	}
 
-	variable, err := context.ProjectConfig.GetVariableByKey(featureKey, variableKey)
+	variable, err := decisionContext.ProjectConfig.GetVariableByKey(featureKey, variableKey)
 	if err != nil {
 		return "", "", err
 	}
@@ -243,11 +243,16 @@ func (o *OptimizelyClient) GetAllFeatureVariables(featureKey string, userContext
 		return enabled, variableMap, err
 	}
 
-	feature := decisionContext.Feature
 	if featureDecision.Variation != nil {
 		enabled = featureDecision.Variation.FeatureEnabled
 	}
 
+	feature := decisionContext.Feature
+	if feature == nil {
+		logger.Warning(fmt.Sprintf(`feature "%s" does not exist`, featureKey))
+		return enabled, variableMap, nil
+	}
+
 	for _, v := range feature.VariableMap {
 		variableMap[v.Key] = v.DefaultValue
 

pkg/client/client_test.go

@@ -1456,6 +1456,29 @@ func TestGetAllFeatureVariablesWithError(t *testing.T) {
 	assert.NoError(t, err)
 }
 
+func TestGetAllFeatureVariablesWithoutFeature(t *testing.T) {
+	invalidFeatureKey := "non-existent-feature"
+	testUserContext := entities.UserContext{ID: "test_user_1"}
+
+	mockConfig := new(MockProjectConfig)
+	mockConfig.On("GetFeatureByKey", invalidFeatureKey).Return(entities.Feature{}, errors.New(""))
+	mockConfigManager := new(MockProjectConfigManager)
+	mockConfigManager.On("GetConfig").Return(mockConfig, nil)
+	mockDecisionService := new(MockDecisionService)
+
+	client := OptimizelyClient{
+		ConfigManager:   mockConfigManager,
+		DecisionService: mockDecisionService,
+	}
+
+	enabled, variationMap, err := client.GetAllFeatureVariables(invalidFeatureKey, testUserContext)
+
+	// if we have a decision, but also a non-fatal error, we should return the decision
+	assert.False(t, enabled)
+	assert.Equal(t, 0, len(variationMap))
+	assert.NoError(t, err)
+}
+
 // Helper Methods
 func getTestFeatureDecision(experiment entities.Experiment, variation entities.Variation, decisionMade bool) decision.FeatureDecision {
 	return decision.FeatureDecision{