[FSSDK-11178] Update impression event for CMAB

[Mat001]

• implement logic for cmab impression events
• Moved CMAB functionality from pkg/decision to pkg/cmab and updated event factory for CMAB impression events.

Jira ticket:
https://jira.sso.episerver.net/browse/FSSDK-11178

[Copilot]

Pull Request Overview

This PR moves CMAB decision logic to a dedicated pkg/cmab package, updates the event factory to support CMAB impression events, and adds corresponding tests.

• Moved and renamed CMAB types and interfaces from pkg/decision to pkg/cmab.
• Introduced CreateCMABImpressionEvent/CreateCMABImpressionUserEvent and updated the event factory and tests.
• Extended DefaultCmabService/DefaultCmabClient to track CMAB decision events.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pkg/event/factory.go	Added CreateCMABImpressionEvent and CreateCMABImpressionUserEvent.
pkg/event/factory_test.go	Added tests for CMAB impression; updated copyright.
pkg/event/events.go	Defined new CMABImpressionEvent type.
pkg/cmab/types.go	Renamed and reorganized CMAB decision types and interfaces.
pkg/cmab/service.go	Refactored service to use new types and track decisions.
pkg/cmab/service_test.go	Updated tests for renamed types and added tracking validation.
pkg/cmab/client.go	Refactored client types, added event processing and tracking stub.

Comments suppressed due to low confidence (1)

pkg/cmab/client.go:280

• [nitpick] There are no unit tests covering the LogImpression/TrackCMABDecision flow in the client; consider adding tests to validate event creation and dispatch.

type EventProcessor interface {

[Copilot]

[nitpick] Printing directly with fmt.Printf in tests can clutter output; use t.Logf or remove debug prints.

Suggested change

	fmt.Printf("CMAB UUID: %s\n", cmabUUID)
	fmt.Printf("UserEvent UUID: %s\n", userEvent.UUID)
	t.Logf("CMAB UUID: %s", cmabUUID)
	t.Logf("UserEvent UUID: %s", userEvent.UUID)

[Copilot]

The EventProcessor interface defines Process(...), not ProcessEvent; update the call or interface to match.

Suggested change

	c.eventProcessor.ProcessEvent(userEvent)
	c.eventProcessor.Process(userEvent)

[Copilot]

LogImpression is currently unimplemented and always errors; implement the logic or remove this stub to avoid runtime failures.

Suggested change

	// Instead of directly creating an event, we'll delegate this to the client
	// that has access to the event package
	return fmt.Errorf("CMAB impression logging not implemented")
	// Get experiment from project config
	experiment, err := projectConfig.GetExperimentByID(ruleID)
	if err != nil {
	return fmt.Errorf("error getting experiment: %w", err)
	}
	// Create variation object
	variation := entities.Variation{
	ID: variationID,
	Key: variationKey,
	}
	// Create user context
	userContext := entities.UserContext{
	ID: userID,
	Attributes: attributes,
	}
	// Look for associated feature flag (if any)
	flagKey := ""
	featureList := projectConfig.GetFeatureList()
	for _, feature := range featureList {
	for _, featureExperiment := range feature.FeatureExperiments {
	if featureExperiment.ID == ruleID {
	flagKey = feature.Key
	break
	}
	}
	if flagKey != "" {
	break
	}
	}
	// Create user event with CMAB impression
	userEvent, shouldDispatch := event.CreateCMABImpressionUserEvent(
	projectConfig,
	experiment,
	&variation,
	userContext,
	flagKey,
	experiment.Key, // ruleKey
	"experiment", // ruleType
	true,
	cmabUUID,
	)
	// Process the event if it should be dispatched
	if shouldDispatch {
	if !eventProcessor.Process(userEvent) {
	return fmt.Errorf("failed to process CMAB impression event")
	}
	}
	return nil

[raju-opti]

We need to also update the sent impression event when a cmab decison is made.

[Mat001]

this is PR has been replaced by a cleaner one #408