Merge pull request #259 from MJMortimer/f-InvoiceIds

Add support for find invoices by ids list beta functionality

Author: MJMortimer

CoreTests/Integration/Invoices/Find.cs

@@ -26,6 +26,16 @@ public void find_by_id()
             Assert.AreEqual(expected, id);
         }
 
+        [Test]
+        public void find_by_id_list()
+        {
+            var created = Given_an_invoice();
+            var invoices = Api.Invoices.Ids(new[] {created.Id}).Find().ToList();
+
+            Assert.AreEqual(1, invoices.Count());
+            Assert.AreEqual(created.Id, invoices.First().Id);
+        }
+
         [Test]
         public void find_by_value()
         {

Xero.Api/Core/Endpoints/InvoicesEndpoint.cs

@@ -13,6 +13,7 @@ namespace Xero.Api.Core.Endpoints
     public interface IInvoicesEndpoint : IXeroUpdateEndpoint<InvoicesEndpoint, Invoice, InvoicesRequest, InvoicesResponse>, IPageableEndpoint<IInvoicesEndpoint>
     {
         OnlineInvoice RetrieveOnlineInvoiceUrl(Guid invoiceId);
+        IInvoicesEndpoint Ids(IEnumerable<Guid> ids);
     }
 
     public class InvoicesEndpoint
@@ -30,6 +31,12 @@ public IInvoicesEndpoint Page(int page)
             return this;
         }
 
+        public IInvoicesEndpoint Ids(IEnumerable<Guid> ids)
+        {
+            AddParameter("ids", string.Join(",", ids));
+            return this;
+        }
+
         public override void ClearQueryString()
         {
             base.ClearQueryString();