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Created February 16, 2017 01:41
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using System;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using Microsoft.Azure.Documents;
using Microsoft.Azure.Documents.Client;
using Shouldly;
using Xunit;
namespace Demo
public class OptimtimisticConcurrencyTests
private readonly DocumentClient _client;
private const string EndpointUrl = "https://localhost:8081";
private const string AuthorizationKey = "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==";
private const string DatabaseId = "ConcurrencyDemo";
private const string CollectionId = "Customers";
public OptimtimisticConcurrencyTests()
_client = new DocumentClient(new Uri(EndpointUrl), AuthorizationKey);
public async Task Should_Throw_With_PreconditionFailed()
// Setup our Database and add a new Customer
var dbSetup = new DatabaseSetup(_client);
await dbSetup.Init(DatabaseId, CollectionId);
var addCustomer = new Customer(Guid.NewGuid().ToString(), "Demo");
await dbSetup.AddCustomer(addCustomer);
// Fetch out the Document (Customer)
var document = (from f in dbSetup.Client.CreateDocumentQuery(dbSetup.Collection.SelfLink)
where f.Id == addCustomer.Id
select f).AsEnumerable().FirstOrDefault();
// Cast the Document to our Customer & make a data change
var editCustomer = (Customer) (dynamic) document;
editCustomer.Name = "Changed";
// Using Access Conditions gives us the ability to use the ETag from our fetched document for optimistic concurrency.
var ac = new AccessCondition {Condition = document.ETag, Type = AccessConditionType.IfMatch};
// Replace our document, which will succeed with the correct ETag
await dbSetup.Client.ReplaceDocumentAsync(document.SelfLink, editCustomer,
new RequestOptions {AccessCondition = ac});
// Replace again, which will fail since our (same) ETag is now invalid
var ex = await dbSetup.Client.ReplaceDocumentAsync(document.SelfLink, editCustomer,
new RequestOptions {AccessCondition = ac}).ShouldThrowAsync<DocumentClientException>();
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