update 4b90b35 for these changes

pkg/reporting/batcher_test.go

@@ -1,12 +1,30 @@
 package reporting
 
 import (
+	"bytes"
 	"testing"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/assert"
 )
 
+type csvBatchBuilder struct {
+	buf     bytes.Buffer
+	started bool
+}
+
+func (b *csvBatchBuilder) Add(event string) {
+	if b.started {
+		b.buf.Write([]byte{','})
+	}
+	b.buf.Write([]byte(event))
+	b.started = true
+}
+
+func (b *csvBatchBuilder) Finish() []byte {
+	return b.buf.Bytes()
+}
+
 func TestEventBatching(t *testing.T) {
 	targetBatchSize := 3
 
@@ -16,7 +34,14 @@ func TestEventBatching(t *testing.T) {
 	}
 	gauge := prometheus.NewGauge(prometheus.GaugeOpts{})
 
-	batcher := newEventBatcher[string](targetBatchSize, notify, gauge)
+	newBatch := func() BatchBuilder[string] {
+		return &csvBatchBuilder{
+			buf:     bytes.Buffer{},
+			started: false,
+		}
+	}
+
+	batcher := newEventBatcher(targetBatchSize, newBatch, notify, gauge)
 
 	// First batch:
 	// Add a small number of items to the batch, and then explicitly request early completion.
@@ -29,7 +54,9 @@ func TestEventBatching(t *testing.T) {
 	batcher.finishOngoing()
 	// check that this batch was completed:
 	assert.Equal(t, true, notified)
-	assert.Equal(t, []batch[string]{{events: []string{"b1-1", "b1-2"}}}, batcher.peekCompleted())
+	assert.Equal(t, []batch[string]{
+		{count: 2, serialized: []byte("b1-1,b1-2")},
+	}, batcher.peekCompleted())
 	// clear the current batch:
 	notified = false
 	batcher.dropCompleted(1)
@@ -51,8 +78,8 @@ func TestEventBatching(t *testing.T) {
 	notified = false // reset the notification
 	// check that the batches so far match what we expect:
 	assert.Equal(t, []batch[string]{
-		{events: []string{"b2-1", "b2-2", "b2-3"}},
-		{events: []string{"b3-1", "b3-2", "b3-3"}},
+		{count: 3, serialized: []byte("b2-1,b2-2,b2-3")},
+		{count: 3, serialized: []byte("b3-1,b3-2,b3-3")},
 	}, batcher.peekCompleted())
 	// add the last batch:
 	batcher.enqueue("b4-1")
@@ -62,16 +89,16 @@ func TestEventBatching(t *testing.T) {
 	assert.Equal(t, true, notified)
 	// Check that the final batches are what we expect
 	assert.Equal(t, []batch[string]{
-		{events: []string{"b2-1", "b2-2", "b2-3"}},
-		{events: []string{"b3-1", "b3-2", "b3-3"}},
-		{events: []string{"b4-1", "b4-2", "b4-3"}},
+		{count: 3, serialized: []byte("b2-1,b2-2,b2-3")},
+		{count: 3, serialized: []byte("b3-1,b3-2,b3-3")},
+		{count: 3, serialized: []byte("b4-1,b4-2,b4-3")},
 	}, batcher.peekCompleted())
 	// Consume one batch:
 	batcher.dropCompleted(1)
 	// and now, it should just be b3 and b4:
 	assert.Equal(t, []batch[string]{
-		{events: []string{"b3-1", "b3-2", "b3-3"}},
-		{events: []string{"b4-1", "b4-2", "b4-3"}},
+		{count: 3, serialized: []byte("b3-1,b3-2,b3-3")},
+		{count: 3, serialized: []byte("b4-1,b4-2,b4-3")},
 	}, batcher.peekCompleted())
 	// consume the final two:
 	batcher.dropCompleted(2)