fix generated formats

pkg/agent/billing/clients.go

@@ -93,7 +93,7 @@ func createClients(ctx context.Context, logger *zap.Logger, cfg ClientsConfig) (
 
 func jsonArrayBatch[B reporting.IOBuffer](buf func() B) func() reporting.BatchBuilder[*IncrementalEvent] {
 	return func() reporting.BatchBuilder[*IncrementalEvent] {
-		return reporting.NewJSONArrayBuilder[*IncrementalEvent](buf())
+		return reporting.NewJSONArrayBuilder[*IncrementalEvent](buf(), "events")
 	}
 }
 

pkg/agent/scalingevents/clients.go

@@ -69,7 +69,7 @@ func createClients(ctx context.Context, logger *zap.Logger, cfg ClientsConfig) (
 
 func jsonLinesBatch[B reporting.IOBuffer](buf func() B) func() reporting.BatchBuilder[ScalingEvent] {
 	return func() reporting.BatchBuilder[ScalingEvent] {
-		return reporting.NewJSONArrayBuilder[ScalingEvent](buf())
+		return reporting.NewJSONLinesBuilder[ScalingEvent](buf())
 	}
 }
 

pkg/reporting/batch_jsonarray.go

@@ -10,22 +10,42 @@ var _ BatchBuilder[int] = (*JSONArrayBuilder[int])(nil)
 // JSONArrayBuilder is a BatchBuilder where all the events in a batch are serialized as a single
 // large JSON array.
 type JSONArrayBuilder[E any] struct {
-	buf     IOBuffer
-	started bool
+	buf          IOBuffer
+	started      bool
+	nestingCount int
 }
 
 // NewJSONArrayBatch creates a new JSONArrayBuilder using the underlying IOBuffer to potentially
 // process the JSON encoding -- either with ByteBuffer for plaintext or GZIPBuffer for gzip
 // compression.
-func NewJSONArrayBuilder[E any](buf IOBuffer) *JSONArrayBuilder[E] {
+func NewJSONArrayBuilder[E any](buf IOBuffer, nestedFields ...string) *JSONArrayBuilder[E] {
+	for _, fieldName := range nestedFields {
+		// note: use a discrete json.Marhsal here instead of json.Encoder because encoder adds a
+		// newline at the end, and that'll make the formatting weird for us.
+		encodedField, err := json.Marshal(fieldName)
+		if err != nil {
+			panic(fmt.Sprintf("failed to JSON encode: %s", fieldName))
+		}
+
+		if _, err := buf.Write([]byte{'{'}); err != nil {
+			panic(fmt.Sprintf("failed to write: %s", err))
+		}
+		if _, err := buf.Write(encodedField); err != nil {
+			panic(fmt.Sprintf("failed to write: %s", err))
+		}
+		if _, err := buf.Write([]byte{':'}); err != nil {
+			panic(fmt.Sprintf("failed to write: %s", err))
+		}
+	}
 	// open the array:
 	if _, err := buf.Write([]byte{'['}); err != nil {
 		panic(fmt.Sprintf("failed to write: %s", err))
 	}
 
 	return &JSONArrayBuilder[E]{
-		buf:     buf,
-		started: false,
+		buf:          buf,
+		started:      false,
+		nestingCount: len(nestedFields),
 	}
 }
 
@@ -53,6 +73,11 @@ func (b *JSONArrayBuilder[E]) Finish() []byte {
 	if _, err := b.buf.Write([]byte("\n]")); err != nil {
 		panic(fmt.Sprintf("failed to write: %s", err))
 	}
+	for i := 0; i < b.nestingCount; i++ {
+		if _, err := b.buf.Write([]byte("}")); err != nil {
+			panic(fmt.Sprintf("failed to write: %s", err))
+		}
+	}
 
 	return b.buf.Collect()
 }