maybe improve tests

meters/stripe/stripe.go

@@ -118,13 +118,19 @@ func (m *StripeMeterProvider) Flush() error {
 	// Convert events to API payload
 	eventPayloads := make([]interface{}, len(events))
 	for i, evt := range events {
+		// Build payload with dimensions
+		payload := map[string]interface{}{
+			"stripe_customer_id": evt.CustomerId,
+			"value":              fmt.Sprintf("%f", evt.Value),
+		}
+		// I think we can add extra "dimensions" to payload, but not sure
+		for _, dim := range evt.Dimensions {
+			payload[dim.Key] = dim.Value
+		}
+
 		eventPayloads[i] = map[string]interface{}{
 			"event_name": evt.EventName,
-			"payload": map[string]interface{}{
-				"stripe_customer_id": evt.CustomerId,
-				"value":              fmt.Sprintf("%f", evt.Value),
-				"metadata":           buildMetadataFromDimensions(nil, evt.Dimensions),
-			},
+			"payload":    payload,
 		}
 	}
 
@@ -171,17 +177,6 @@ func (m *StripeMeterProvider) sendMeter(user meters.MeterUser, meterName string,
 	return nil
 }
 
-func buildMetadataFromDimensions(cfgDims, extraDims meters.Dimensions) map[string]string {
-	metadata := make(map[string]string)
-	for _, d := range cfgDims {
-		metadata[d.Key] = d.Value
-	}
-	for _, d := range extraDims {
-		metadata[d.Key] = d.Value
-	}
-	return metadata
-}
-
 func (m *StripeMeterProvider) GetValue(user meters.MeterUser, meterName string, startTime time.Time, endTime time.Time, dims meters.Dimensions) (float64, bool) {
 	// TODO: Implement GetValue using https://docs.stripe.com/api/billing/meter-event-summary
 	// Not needed

meters/stripe/stripe_test.go

@@ -3,6 +3,7 @@ package stripe
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"os"
 	"testing"
@@ -216,6 +217,7 @@ func TestStripeMeterWithMock(t *testing.T) {
 			return nil
 		}).Times(1)
 
+		// Verify the correct payload structure with dimensions
 		mockBackend.EXPECT().
 			CallRaw(
 				gomock.Any(),
@@ -224,7 +226,33 @@ func TestStripeMeterWithMock(t *testing.T) {
 				gomock.Any(),
 				gomock.Any(),
 				gomock.Any(),
-			).Return(nil).Times(1)
+			).DoAndReturn(func(_ interface{}, _ interface{}, _ interface{}, body interface{}, _ interface{}, _ interface{}) error {
+			var payload struct {
+				Events []struct {
+					EventName string                 `json:"event_name"`
+					Payload   map[string]interface{} `json:"payload"`
+				} `json:"events"`
+			}
+			if err := json.Unmarshal([]byte(body.(string)), &payload); err != nil {
+				return fmt.Errorf("failed to unmarshal payload: %w", err)
+			}
+			if len(payload.Events) != 1 {
+				return fmt.Errorf("expected 1 event, got %d", len(payload.Events))
+			}
+			evt := payload.Events[0]
+			// Verify event name
+			if evt.EventName != "test_meter" {
+				return fmt.Errorf("expected event_name 'test_meter', got '%s'", evt.EventName)
+			}
+			// Verify payload structure
+			p := evt.Payload
+			if p["stripe_customer_id"] != "customer-123" ||
+				p["value"] != "100.000000" ||
+				p["2"] != "extra_dimension" {
+				return fmt.Errorf("invalid payload: %v", p)
+			}
+			return nil
+		}).Times(1)
 
 		err := mp.sendMeter(testUser, "test_meter", 100, meters.Dimensions{
 			{Key: "2", Value: "extra_dimension"},