Flexible billing primitives

.travis.yml

@@ -23,7 +23,7 @@ cache:
 
 env:
   global:
-    - STRIPE_MOCK_VERSION=0.8.0
+    - STRIPE_MOCK_VERSION=0.11.0
 
 go:
   - "1.7"

form/form.go

@@ -190,7 +190,7 @@ func buildArrayOrSliceEncoder(t reflect.Type) encoderFunc {
 			elemF(values, indexV, arrNames, indexV.Kind() == reflect.Ptr, nil)
 
 			if isAppender(indexV.Type()) && !indexV.IsNil() {
-				v.Interface().(Appender).AppendTo(values, arrNames)
+				indexV.Interface().(Appender).AppendTo(values, arrNames)
 			}
 		}
 	}

plan.go

@@ -1,24 +1,74 @@
 package stripe
 
+import (
+	"strconv"
+
+	"github.com/stripe/stripe-go/form"
+)
+
 // PlanInterval is the list of allowed values for a plan's interval.
 // Allowed values are "day", "week", "month", "year".
 type PlanInterval string
 
+const (
+	// PlanBillingSchemeTiered indicates that the price per single unit is tiered
+	// and can change with the total number of units.
+	PlanBillingSchemeTiered string = "tiered"
+	// PlanBillingSchemePerUnit indicates that each unit is billed at a fixed
+	// price.
+	PlanBillingSchemePerUnit string = "per_unit"
+)
+
+const (
+	// PlanUsageTypeLicensed indicates that the set Quantity on a subscription item
+	// will be used to bill for a subscription.
+	PlanUsageTypeLicensed string = "licensed"
+	// PlanUsageTypeMetered indicates that usage records must be reported instead
+	// of setting a Quantity on a subscription item.
+	PlanUsageTypeMetered string = "metered"
+)
+
+const (
+	// PlanTransformUsageModeRoundDown represents a bucket billing configuration: a partially
+	// filled bucket will count as an empty bucket.
+	PlanTransformUsageModeRoundDown string = "round_down"
+	// PlanTransformUsageModeRoundUp represents a bucket billing configuration: a partially
+	// filled bucket will count as a full bucket.
+	PlanTransformUsageModeRoundUp string = "round_up"
+)
+
+// PlanTransformUsage represents the bucket billing configuration.
+type PlanTransformUsage struct {
+	DivideBy int64  `json:"bucket_size"`
+	Round    string `json:"round"`
+}
+
+// PlanTier configures tiered pricing
+type PlanTier struct {
+	Amount uint64 `json:"amount"`
+	UpTo   uint64 `json:"up_to"`
+}
+
 // Plan is the resource representing a Stripe plan.
 // For more details see https://stripe.com/docs/api#plans.
 type Plan struct {
-	Amount        uint64            `json:"amount"`
-	Created       int64             `json:"created"`
-	Currency      Currency          `json:"currency"`
-	Deleted       bool              `json:"deleted"`
-	ID            string            `json:"id"`
-	Interval      PlanInterval      `json:"interval"`
-	IntervalCount uint64            `json:"interval_count"`
-	Live          bool              `json:"livemode"`
-	Meta          map[string]string `json:"metadata"`
-	Nickname      string            `json:"nickname"`
-	Product       string            `json:"product"`
-	TrialPeriod   uint64            `json:"trial_period_days"`
+	Amount         uint64              `json:"amount"`
+	BillingScheme  string              `json:"billing_scheme"`
+	Created        int64               `json:"created"`
+	Currency       Currency            `json:"currency"`
+	Deleted        bool                `json:"deleted"`
+	ID             string              `json:"id"`
+	Interval       PlanInterval        `json:"interval"`
+	IntervalCount  uint64              `json:"interval_count"`
+	Live           bool                `json:"livemode"`
+	Meta           map[string]string   `json:"metadata"`
+	Nickname       string              `json:"nickname"`
+	Product        string              `json:"product"`
+	Tiers          []*PlanTier         `json:"tiers"`
+	TiersMode      string              `json:"tiers_mode"`
+	TransformUsage *PlanTransformUsage `json:"transform_usage"`
+	TrialPeriod    uint64              `json:"trial_period_days"`
+	UsageType      string              `json:"usage_type"`
 }
 
 // PlanList is a list of plans as returned from a list endpoint.
@@ -38,17 +88,45 @@ type PlanListParams struct {
 // PlanParams is the set of parameters that can be used when creating or updating a plan.
 // For more details see https://stripe.com/docs/api#create_plan and https://stripe.com/docs/api#update_plan.
 type PlanParams struct {
-	Params        `form:"*"`
-	Amount        uint64             `form:"amount"`
-	AmountZero    bool               `form:"amount,zero"`
-	Currency      Currency           `form:"currency"`
-	ID            string             `form:"id"`
-	Interval      PlanInterval       `form:"interval"`
-	IntervalCount uint64             `form:"interval_count"`
-	Nickname      string             `form:"nickname"`
-	Product       *PlanProductParams `form:"product"`
-	ProductID     *string            `form:"product"`
-	TrialPeriod   uint64             `form:"trial_period_days"`
+	Params         `form:"*"`
+	Amount         uint64                    `form:"amount"`
+	AmountZero     bool                      `form:"amount,zero"`
+	BillingScheme  string                    `form:"billing_scheme"`
+	Currency       Currency                  `form:"currency"`
+	ID             string                    `form:"id"`
+	Interval       PlanInterval              `form:"interval"`
+	IntervalCount  uint64                    `form:"interval_count"`
+	Nickname       string                    `form:"nickname"`
+	Product        *PlanProductParams        `form:"product"`
+	ProductID      *string                   `form:"product"`
+	Tiers          []*PlanTierParams         `form:"tiers,indexed"`
+	TiersMode      string                    `form:"tiers_mode"`
+	TransformUsage *PlanTransformUsageParams `form:"transform_usage"`
+	TrialPeriod    uint64                    `form:"trial_period_days"`
+	UsageType      string                    `form:"usage_type"`
+}
+
+// PlanTransformUsageParams represents the bucket billing configuration.
+type PlanTransformUsageParams struct {
+	DivideBy int64  `form:"bucket_size"`
+	Round    string `form:"round"`
+}
+
+// PlanTierParams configures tiered pricing
+type PlanTierParams struct {
+	Params  `form:"*"`
+	Amount  uint64 `form:"amount"`
+	UpTo    uint64 `form:"-"` // handled in custom AppendTo
+	UpToInf bool   `form:"-"` // handled in custom AppendTo
+}
+
+// AppendTo implements custom up_to serialisation logic for tiers configuration
+func (config *PlanTierParams) AppendTo(body *form.Values, keyParts []string) {
+	if config.UpToInf {
+		body.Add(form.FormatKey(append(keyParts, "up_to")), "inf")
+	} else {
+		body.Add(form.FormatKey(append(keyParts, "up_to")), strconv.FormatUint(config.UpTo, 10))
+	}
 }
 
 // PlanProductParams is the set of parameters that can be used when creating a product inside a plan

plan_test.go

@@ -44,22 +44,34 @@ func TestPlanParams_AppendTo(t *testing.T) {
 		Name:                "Sapphire Elite",
 		StatementDescriptor: "SAPPHIRE",
 	}
-	productId := "prod_123abc"
+	productID := "prod_123abc"
+	tiers := []*PlanTierParams{{Amount: 123, UpTo: 321}, {Amount: 123, UpToInf: true}}
 	testCases := []struct {
 		field  string
 		params *PlanParams
 		want   interface{}
 	}{
+		{"amount", &PlanParams{}, ""},
+		{"amount", &PlanParams{Amount: 0, AmountZero: false}, ""},
+		{"amount", &PlanParams{Amount: 0, AmountZero: true}, strconv.FormatUint(0, 10)},
 		{"amount", &PlanParams{Amount: 123}, strconv.FormatUint(123, 10)},
 		{"currency", &PlanParams{Currency: "USD"}, "USD"},
 		{"id", &PlanParams{ID: "sapphire-elite"}, "sapphire-elite"},
-		{"interval", &PlanParams{Interval: "month"}, "month"},
 		{"interval_count", &PlanParams{IntervalCount: 3}, strconv.FormatUint(3, 10)},
+		{"interval", &PlanParams{Interval: "month"}, "month"},
+		{"product", &PlanParams{ProductID: &productID}, "prod_123abc"},
 		{"product[id]", &PlanParams{Product: &productParams}, "ID"},
 		{"product[name]", &PlanParams{Product: &productParams}, "Sapphire Elite"},
 		{"product[statement_descriptor]", &PlanParams{Product: &productParams}, "SAPPHIRE"},
-		{"product", &PlanParams{ProductID: &productId}, "prod_123abc"},
+		{"tiers_mode", &PlanParams{TiersMode: "volume"}, "volume"},
+		{"tiers[0][amount]", &PlanParams{Tiers: tiers}, strconv.FormatUint(123, 10)},
+		{"tiers[0][up_to]", &PlanParams{Tiers: tiers}, strconv.FormatUint(321, 10)},
+		{"tiers[1][amount]", &PlanParams{Tiers: tiers}, strconv.FormatUint(123, 10)},
+		{"tiers[1][up_to]", &PlanParams{Tiers: tiers}, "inf"},
+		{"transform_usage[bucket_size]", &PlanParams{TransformUsage: &PlanTransformUsageParams{DivideBy: 123, Round: "round_up"}}, strconv.FormatUint(123, 10)},
+		{"transform_usage[round]", &PlanParams{TransformUsage: &PlanTransformUsageParams{DivideBy: 123, Round: "round_up"}}, "round_up"},
 		{"trial_period_days", &PlanParams{TrialPeriod: 123}, strconv.FormatUint(123, 10)},
+		{"usage_type", &PlanParams{UsageType: "metered"}, "metered"},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.field, func(t *testing.T) {

scripts/check_gofmt.sh

@@ -10,7 +10,7 @@ find_files() {
 
 bad_files=$(find_files | xargs gofmt -s -l)
 if [[ -n "${bad_files}" ]]; then
-    echo "!!! gofmt needs to be run on the following files: "
+    echo "!!! gofmt -s needs to be run on the following files: "
     echo "${bad_files}"
     exit 1
 fi

usage_record.go

@@ -0,0 +1,33 @@
+package stripe
+
+const (
+	// UsageRecordParamsActionIncrement indicates that if two usage records conflict
+	// (i.E. are reported a the same timestamp), their Quantity will be summed
+	UsageRecordParamsActionIncrement string = "increment"
+
+	// UsageRecordParamsActionSet indicates that if two usage records conflict
+	// (i.E. are reported a the same timestamp), the Quantity of the most recent
+	// usage record will overwrite any other quantity.
+	UsageRecordParamsActionSet string = "set"
+)
+
+// UsageRecord represents a usage record.
+// See https://stripe.com/docs/api#usage_records
+type UsageRecord struct {
+	ID               string `json:"id"`
+	Live             bool   `json:"livemode"`
+	Quantity         uint64 `json:"quantity"`
+	SubscriptionItem string `json:"subscription_item"`
+	Timestamp        uint64 `json:"timestamp"`
+}
+
+// UsageRecordParams create a usage record for a specified subscription item
+// and date, and fills it with a quantity.
+type UsageRecordParams struct {
+	Params           `form:"*"`
+	Action           string `form:"action"`
+	Quantity         uint64 `form:"quantity"`
+	QuantityZero     bool   `form:"quantity,zero"`
+	SubscriptionItem string `form:"-"` // passed in the URL
+	Timestamp        uint64 `form:"timestamp"`
+}

usage_record_test.go

@@ -0,0 +1,30 @@
+package stripe
+
+import (
+	"strconv"
+	"testing"
+
+	assert "github.com/stretchr/testify/require"
+	"github.com/stripe/stripe-go/form"
+)
+
+func TestUsageRecordParams_AppendTo(t *testing.T) {
+	testCases := []struct {
+		field  string
+		params *UsageRecordParams
+		want   interface{}
+	}{
+		{"quantity", &UsageRecordParams{Quantity: 2000}, strconv.FormatUint(2000, 10)},
+		{"quantity", &UsageRecordParams{QuantityZero: true}, strconv.FormatUint(0, 10)},
+		{"timestamp", &UsageRecordParams{Timestamp: 123123123}, strconv.FormatUint(123123123, 10)},
+		{"action", &UsageRecordParams{Action: "increment"}, "increment"},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.field, func(t *testing.T) {
+			body := &form.Values{}
+			form.AppendTo(body, tc.params)
+			values := body.ToValues()
+			assert.Equal(t, tc.want, values.Get(tc.field))
+		})
+	}
+}

usagerecord/client.go

@@ -0,0 +1,38 @@
+// Package usage_record provides the /subscription_items/{SUBSCRIPTION_ITEM_ID}/usage_records APIs
+package usagerecord
+
+import (
+	"fmt"
+	"net/url"
+
+	stripe "github.com/stripe/stripe-go"
+	"github.com/stripe/stripe-go/form"
+)
+
+// Client is used to invoke /plans APIs.
+type Client struct {
+	B   stripe.Backend
+	Key string
+}
+
+// New creates a new usage record.
+// For more details see https://stripe.com/docs/api#usage_records
+func New(params *stripe.UsageRecordParams) (*stripe.UsageRecord, error) {
+	return getC().New(params)
+}
+
+// New internal implementation to create a new usage record.
+func (c Client) New(params *stripe.UsageRecordParams) (*stripe.UsageRecord, error) {
+	body := &form.Values{}
+	form.AppendTo(body, params)
+
+	url := fmt.Sprintf("/subscription_items/%s/usage_records", url.QueryEscape(params.SubscriptionItem))
+	record := &stripe.UsageRecord{}
+	err := c.B.Call("POST", url, c.Key, body, &params.Params, record)
+
+	return record, err
+}
+
+func getC() Client {
+	return Client{stripe.GetBackend(stripe.APIBackend), stripe.Key}
+}

usagerecord/client_test.go

@@ -0,0 +1,22 @@
+package usagerecord
+
+import (
+	"testing"
+	"time"
+
+	assert "github.com/stretchr/testify/require"
+	stripe "github.com/stripe/stripe-go"
+	_ "github.com/stripe/stripe-go/testing"
+)
+
+func TestUsageRecordNew(t *testing.T) {
+	now := uint64(time.Now().Unix())
+	usageRecord, err := New(&stripe.UsageRecordParams{
+		Quantity:         123,
+		Timestamp:        now,
+		Action:           stripe.UsageRecordParamsActionIncrement,
+		SubscriptionItem: "si_123",
+	})
+	assert.Nil(t, err)
+	assert.NotNil(t, usageRecord)
+}