Fixes Stripe Billing Anchor Edge Case (#3201)

backend/internal/cmds/mgmt/serve/connect/cmd.go

@@ -86,7 +86,7 @@ import (
 	promv1 "github.com/prometheus/client_golang/api/prometheus/v1"
 	promconfig "github.com/prometheus/common/config"
 
-	stripeapiclient "github.com/stripe/stripe-go/v79/client"
+	stripeapiclient "github.com/stripe/stripe-go/v81/client"
 )
 
 func NewCmd() *cobra.Command {

backend/services/mgmt/v1alpha1/integration_tests/anonymization-service_integration_test.go

@@ -11,7 +11,7 @@ import (
 	integrationtests_test "github.com/nucleuscloud/neosync/backend/pkg/integration-test"
 	"github.com/nucleuscloud/neosync/internal/gotypeutil"
 	"github.com/stretchr/testify/require"
-	"github.com/stripe/stripe-go/v79"
+	"github.com/stripe/stripe-go/v81"
 )
 
 func (s *IntegrationTestSuite) Test_AnonymizeService_AnonymizeMany() {

backend/services/mgmt/v1alpha1/integration_tests/user-account-service_integration_test.go

@@ -19,7 +19,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
-	"github.com/stripe/stripe-go/v79"
+	"github.com/stripe/stripe-go/v81"
 )
 
 var (

backend/services/mgmt/v1alpha1/user-account-service/billing.go

@@ -19,7 +19,7 @@ import (
 	"github.com/nucleuscloud/neosync/backend/internal/neosyncdb"
 	"github.com/nucleuscloud/neosync/backend/internal/userdata"
 	"github.com/nucleuscloud/neosync/internal/billing"
-	"github.com/stripe/stripe-go/v79"
+	"github.com/stripe/stripe-go/v81"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
@@ -240,9 +240,6 @@ func (s *Service) GetAccountBillingCheckoutSession(
 	if err != nil {
 		return nil, err
 	}
-	if err != nil {
-		return nil, err
-	}
 
 	// retrieve the account, creates a customer id if one doesn't already exist
 	account, err := s.db.UpsertStripeCustomerId(

backend/services/mgmt/v1alpha1/user-account-service/users.go

@@ -23,7 +23,7 @@ import (
 	"github.com/nucleuscloud/neosync/backend/internal/userdata"
 	"github.com/nucleuscloud/neosync/backend/internal/version"
 	"github.com/nucleuscloud/neosync/internal/billing"
-	"github.com/stripe/stripe-go/v79"
+	"github.com/stripe/stripe-go/v81"
 	"golang.org/x/sync/errgroup"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )

go.mod

@@ -61,7 +61,7 @@ require (
 	github.com/spf13/cobra v1.8.1
 	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.10.0
-	github.com/stripe/stripe-go/v79 v79.12.0
+	github.com/stripe/stripe-go/v81 v81.3.0
 	github.com/testcontainers/testcontainers-go v0.35.0
 	github.com/testcontainers/testcontainers-go/modules/mongodb v0.35.0
 	github.com/testcontainers/testcontainers-go/modules/mssql v0.35.0

go.sum

@@ -2103,8 +2103,8 @@ github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXl
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/stripe/stripe-go/v79 v79.12.0 h1:HQs/kxNEB3gYA7FnkSFkp0kSOeez0fsmCWev6SxftYs=
-github.com/stripe/stripe-go/v79 v79.12.0/go.mod h1:cuH6X0zC8peY6f1AubHwgJ/fJSn2dh5pfiCr6CjyKVU=
+github.com/stripe/stripe-go/v81 v81.3.0 h1:tvNgK3RcX0oKE/hB6oifpa+InEA/UVDbU/Xjwydz+nk=
+github.com/stripe/stripe-go/v81 v81.3.0/go.mod h1:C/F4jlmnGNacvYtBp/LUHCvVUJEZffFQCobkzwY1WOo=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/testcontainers/testcontainers-go v0.35.0 h1:uADsZpTKFAtp8SLK+hMwSaa+X+JiERHtd4sQAFmXeMo=

internal/billing/stripe-billing.go

@@ -5,8 +5,8 @@ import (
 	"log/slog"
 	"time"
 
-	"github.com/stripe/stripe-go/v79"
-	stripeapiclient "github.com/stripe/stripe-go/v79/client"
+	"github.com/stripe/stripe-go/v81"
+	stripeapiclient "github.com/stripe/stripe-go/v81/client"
 )
 
 type SubscriptionIter interface {
@@ -130,9 +130,11 @@ func (c *Client) NewMeterEvent(req *MeterEventRequest) (*stripe.BillingMeterEven
 }
 
 func getNextMonthBillingCycleAnchor(date time.Time) int64 {
-	// Calculate the first day of the next month
-	nextMonth := date.AddDate(0, 1, 0)
-	firstOfNextMonth := time.Date(nextMonth.Year(), nextMonth.Month(), 1, 0, 0, 0, 0, date.Location())
+	dateUtc := date.UTC()
+	// First set to the 1st of the current month
+	firstOfMonth := time.Date(dateUtc.Year(), dateUtc.Month(), 1, 0, 0, 0, 0, dateUtc.Location())
+	// Then add one month - this avoids day rollover issues
+	firstOfNextMonth := firstOfMonth.AddDate(0, 1, 0)
 	return firstOfNextMonth.Unix()
 }
 

internal/billing/stripe-billing_test.go

@@ -23,7 +23,41 @@ func Test_getNextMonthBillingCycleAnchor(t *testing.T) {
 	t.Run("timezone", func(t *testing.T) {
 		date := time.Date(2024, time.December, 1, 0, 0, 0, 0, time.Local)
 		actual := getNextMonthBillingCycleAnchor(date)
-		expected := time.Date(2025, time.January, 1, 0, 0, 0, 0, time.Local).Unix()
+		expected := time.Date(2025, time.January, 1, 0, 0, 0, 0, time.UTC).Unix()
+		require.Equal(t, expected, actual)
+	})
+
+	t.Run("handles utc conversion", func(t *testing.T) {
+		la, err := time.LoadLocation("America/Los_Angeles")
+		require.NoError(t, err)
+		date := time.Date(2025, time.January, 31, 23, 59, 59, 0, la)
+		actual := getNextMonthBillingCycleAnchor(date.UTC())
+		expected := time.Date(2025, time.March, 1, 0, 0, 0, 0, time.UTC).Unix()
+		require.Equal(t, expected, actual)
+	})
+
+	t.Run("handles non existent days", func(t *testing.T) {
+		date := time.Date(2025, time.January, 29, 0, 0, 0, 0, time.UTC)
+		actual := getNextMonthBillingCycleAnchor(date)
+		expected := time.Date(2025, time.February, 1, 0, 0, 0, 0, time.UTC).Unix()
+		require.Equal(t, expected, actual)
+	})
+	t.Run("handles leap year", func(t *testing.T) {
+		date := time.Date(2024, time.January, 29, 0, 0, 0, 0, time.UTC)
+		actual := getNextMonthBillingCycleAnchor(date)
+		expected := time.Date(2024, time.February, 1, 0, 0, 0, 0, time.UTC).Unix()
+		require.Equal(t, expected, actual)
+	})
+	t.Run("handles february leap year", func(t *testing.T) {
+		date := time.Date(2024, time.February, 29, 0, 0, 0, 0, time.UTC)
+		actual := getNextMonthBillingCycleAnchor(date)
+		expected := time.Date(2024, time.March, 1, 0, 0, 0, 0, time.UTC).Unix()
+		require.Equal(t, expected, actual)
+	})
+	t.Run("middle of the month", func(t *testing.T) {
+		date := time.Date(2024, time.February, 15, 0, 0, 0, 0, time.UTC)
+		actual := getNextMonthBillingCycleAnchor(date)
+		expected := time.Date(2024, time.March, 1, 0, 0, 0, 0, time.UTC).Unix()
 		require.Equal(t, expected, actual)
 	})
 }