From e065e2a4555178d10e3ca24d51d02bced00b9abf Mon Sep 17 00:00:00 2001
From: David Leek <david@getunleash.io>
Date: Mon, 9 Oct 2023 09:11:39 +0200
Subject: [PATCH] feat: render segments changes in feature strategy update
 event messages (#4950)

## About the changes

Segment changes in predata and data columns were both showing the new
segments list

Adds formatting of what's changed with segments to feature strategy
update events, so when a user changes the strategy from using
constraints, to using segments instead, it's communicated in event
updates

results in:

admin updated
[sample-toggle](http://localhost/projects/default/features/sample-toggle)
in project [default](http://localhost/projects/default) by updating
strategy Sample Strategy in development constraints from [userId is one
of (1,2,3)] to empty set of constraints; segments from empty set of
segments to (1)


Closes #
#4912

### Important files

- `src/lib/services/feature-toggle-service.ts` - Segment changes in
preData and data
- `src/lib/addons/feature-event-formatter-md.ts` - Formatting segments

## Discussion points

This is an SR least effort PR - we should plan a task where we look at
how to render this list of segments in a more comprehensible way (it's
just rendering ids now)
---
 src/lib/addons/feature-event-formatter-md.ts | 44 +++++++++++++++++---
 src/lib/services/feature-toggle-service.ts   |  8 +++-
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/src/lib/addons/feature-event-formatter-md.ts b/src/lib/addons/feature-event-formatter-md.ts
index 2b499dc1fb..c4609232f3 100644
--- a/src/lib/addons/feature-event-formatter-md.ts
+++ b/src/lib/addons/feature-event-formatter-md.ts
@@ -415,7 +415,11 @@ export class FeatureEventFormatterMd implements FeatureEventFormatter {
             preData?.constraints,
             data?.constraints,
         );
-        const strategySpecificText = [usersText, constraintText]
+        const segmentsText = this.segmentsChangeText(
+            preData?.segments,
+            data?.segments,
+        );
+        const strategySpecificText = [usersText, constraintText, segmentsText]
             .filter((x) => x.length)
             .join(';');
         return `by updating strategy *${this.getStrategyTitle(
@@ -453,11 +457,16 @@ export class FeatureEventFormatterMd implements FeatureEventFormatter {
             preData?.constraints,
             data?.constraints,
         );
+        const segmentsText = this.segmentsChangeText(
+            preData?.segments,
+            data?.segments,
+        );
         const strategySpecificText = [
             stickinessText,
             rolloutText,
             groupIdText,
             constraintText,
+            segmentsText,
         ]
             .filter((txt) => txt.length)
             .join(';');
@@ -468,12 +477,20 @@ export class FeatureEventFormatterMd implements FeatureEventFormatter {
 
     private defaultStrategyChangeText(event: IEvent) {
         const { preData, data, environment } = event;
-        return `by updating strategy *${this.getStrategyTitle(
-            event,
-        )}* in *${environment}*${this.constraintChangeText(
+        const constraintText = this.constraintChangeText(
             preData?.constraints,
             data?.constraints,
-        )}`;
+        );
+        const segmentsText = this.segmentsChangeText(
+            preData?.segments,
+            data?.segments,
+        );
+        const strategySpecificText = [constraintText, segmentsText]
+            .filter((txt) => txt.length)
+            .join(';');
+        return `by updating strategy *${this.getStrategyTitle(
+            event,
+        )}* in *${environment}*${strategySpecificText}`;
     }
 
     private constraintChangeText(
@@ -525,6 +542,23 @@ export class FeatureEventFormatterMd implements FeatureEventFormatter {
             : ` constraints from ${oldConstraintText} to ${newConstraintText}`;
     }
 
+    private segmentsChangeText(
+        oldSegments: string[] = [],
+        newSegments: string[] = [],
+    ) {
+        const formatSegments = (segments: string[]) => {
+            return segments.length === 0
+                ? 'empty set of segments'
+                : `(${segments.join(',')})`;
+        };
+        const oldSegmentsText = formatSegments(oldSegments);
+        const newSegmentsText = formatSegments(newSegments);
+
+        return oldSegmentsText === newSegmentsText
+            ? ''
+            : ` segments from ${oldSegmentsText} to ${newSegmentsText}`;
+    }
+
     format(event: IEvent): {
         text: string;
         url?: string;
diff --git a/src/lib/services/feature-toggle-service.ts b/src/lib/services/feature-toggle-service.ts
index aca23b0795..b365c3949f 100644
--- a/src/lib/services/feature-toggle-service.ts
+++ b/src/lib/services/feature-toggle-service.ts
@@ -718,6 +718,7 @@ class FeatureToggleService {
             projectId,
             updates.segments,
         );
+        const existingSegments = await this.segmentService.getByStrategy(id);
 
         if (existingStrategy.id === id) {
             if (updates.constraints && updates.constraints.length > 0) {
@@ -752,7 +753,7 @@ class FeatureToggleService {
             const data = this.featureStrategyToPublic(strategy, segments);
             const preData = this.featureStrategyToPublic(
                 existingStrategy,
-                segments,
+                existingSegments,
             );
             await this.eventService.storeEvent(
                 new FeatureStrategyUpdateEvent({
@@ -789,6 +790,9 @@ class FeatureToggleService {
 
         if (existingStrategy.id === id) {
             existingStrategy.parameters[name] = String(value);
+            const existingSegments = await this.segmentService.getByStrategy(
+                id,
+            );
             const strategy = await this.featureStrategiesStore.updateStrategy(
                 id,
                 existingStrategy,
@@ -799,7 +803,7 @@ class FeatureToggleService {
             const data = this.featureStrategyToPublic(strategy, segments);
             const preData = this.featureStrategyToPublic(
                 existingStrategy,
-                segments,
+                existingSegments,
             );
             await this.eventService.storeEvent(
                 new FeatureStrategyUpdateEvent({