Add support for PendingInvoiceItemInterval on Subscription

src/Stripe.net/Entities/Subscriptions/Subscription.cs

@@ -240,6 +240,20 @@ public Invoice LatestInvoice
         [JsonProperty("metadata")]
         public Dictionary<string, string> Metadata { get; set; }
 
+        /// <summary>
+        /// Specifies the approximate timestamp on which any pending invoice items will be billed
+        /// according to the schedule provided at <c>PendingInvoiceItemInterval</c>.
+        /// </summary>
+        [JsonProperty("next_pending_invoice_item_invoice")]
+        public long? NextPendingInvoiceItemInvoice { get; set; }
+
+        /// <summary>
+        /// Specifies an interval for how often to bill for any pending invoice items. It is
+        /// analogous to creating an invoice for the given subscription at the specified interval.
+        /// </summary>
+        [JsonProperty("pending_invoice_item_interval")]
+        public SubscriptionPendingInvoiceItemInterval PendingInvoiceItemInterval { get; set; }
+
         #region Expandable PendingSetupIntent
 
         /// <summary>

src/Stripe.net/Entities/Subscriptions/SubscriptionPendingInvoiceItemInterval.cs

@@ -0,0 +1,21 @@
+namespace Stripe
+{
+    using Newtonsoft.Json;
+    using Stripe.Infrastructure;
+
+    public class SubscriptionPendingInvoiceItemInterval : StripeEntity<SubscriptionPendingInvoiceItemInterval>
+    {
+        /// <summary>
+        /// Specifies invoicing frequency. Either <c>day</c>, <c>week</c>, <c>month</c> or
+        /// <c>year</c>.
+        /// </summary>
+        [JsonProperty("interval")]
+        public string Interval { get; set; }
+
+        /// <summary>
+        /// The number of intervals between invoices.
+        /// </summary>
+        [JsonProperty("interval_count")]
+        public long IntervalCount { get; set; }
+    }
+}

src/Stripe.net/Services/Subscriptions/SubscriptionPendingInvoiceItemIntervalOptions.cs

@@ -0,0 +1,20 @@
+namespace Stripe
+{
+    using Newtonsoft.Json;
+
+    public class SubscriptionPendingInvoiceItemIntervalOptions : INestedOptions
+    {
+        /// <summary>
+        /// Specifies invoicing frequency. Either <c>day</c>, <c>week</c>, <c>month</c> or
+        /// <c>year</c>.
+        /// </summary>
+        [JsonProperty("interval")]
+        public string Interval { get; set; }
+
+        /// <summary>
+        /// The number of intervals between invoices.
+        /// </summary>
+        [JsonProperty("interval_count")]
+        public long? IntervalCount { get; set; }
+    }
+}

src/Stripe.net/Services/Subscriptions/SubscriptionSharedOptions.cs

@@ -77,6 +77,13 @@ public abstract class SubscriptionSharedOptions : BaseOptions, IHasMetadata
         [JsonProperty("metadata")]
         public Dictionary<string, string> Metadata { get; set; }
 
+        /// <summary>
+        /// Specifies an interval for how often to bill for any pending invoice items. It is
+        /// analogous to creating an invoice for the given subscription at the specified interval.
+        /// </summary>
+        [JsonProperty("pending_invoice_item_interval")]
+        public SubscriptionPendingInvoiceItemIntervalOptions PendingInvoiceItemInterval { get; set; }
+
         /// <summary>
         /// Indicates if a customer is on session while an invoice payment is attempted.
         /// </summary>