# StoreCancellationContract > Tracon documentation. Tracon is a .NET package family that adds a control > plane on Microsoft Agent Framework, published as NuGet packages that run > inside your own ASP.NET Core application. > > Page: https://tracon.dev/api/tracon.testing.contracts.storage.storecancellationcontract-1/ > Summary: StoreCancellationContract: The promise every store makes about a token that is already cancelled, plus the lifecycle plumbing every store contract shares.
Namespace Tracon.Testing.Contracts.Storage · Assembly Tracon.Testing.Contracts.Xunit.dll
The promise every store makes about a token that is **already cancelled**, plus the lifecycle plumbing every store contract shares. ```csharp public abstract class StoreCancellationContract : IAsyncLifetime, IAsyncDisposable ```
Type Parameters
TStore The store type under test.
Inheritance
object ← StoreCancellationContract<TStore>
Implements
IAsyncLifetime, IAsyncDisposable
Inherited Members
object.GetType(), object.MemberwiseClone(), object.ToString(), object.Equals(object?), object.Equals(object?, object?), object.ReferenceEquals(object?, object?), object.GetHashCode()
## Remarks A store handed a token that is already cancelled throws [OperationCanceledException](https://learn.microsoft.com/dotnet/api/system.operationcanceledexception) and leaves no trace. The write side is the half that matters: throwing on its own proves nothing, because a check placed *after* the work throws too. The contract therefore reads the store back and requires it to be untouched. Cancellation *during* a call is deliberately outside this contract. It races, so no deterministic case can assert where the work stopped. Only a token that was already cancelled when the call started is covered. [Storage.TenantIsolationContract](/api/tracon.testing.contracts.storage/) derives from this class and wires the three hooks to its own seed and count hooks, so a tenant-aware store contract implements nothing extra. The four store contracts that carry no tenant dimension derive from this class directly. ## Constructors ### StoreCancellationContract\(\) ```csharp protected StoreCancellationContract() ``` ## Properties ### Store The store under test. ```csharp protected TStore Store { get; } ``` #### Property Value TStore ## Methods ### Canceled\_token\_throws\_on\_read\(\) ```csharp [Fact] public Task Canceled_token_throws_on_read() ``` #### Returns [Task](https://learn.microsoft.com/dotnet/api/system.threading.tasks.task) ### Canceled\_token\_throws\_on\_write\_and\_leaves\_no\_trace\(\) ```csharp [Fact] public Task Canceled_token_throws_on_write_and_leaves_no_trace() ``` #### Returns [Task](https://learn.microsoft.com/dotnet/api/system.threading.tasks.task) ### CancellableReadAsync\(CancellationToken\) Calls one **read** method of the store with the given token. ```csharp protected abstract ValueTask CancellableReadAsync(CancellationToken cancellationToken) ``` #### Parameters `cancellationToken` [CancellationToken](https://learn.microsoft.com/dotnet/api/system.threading.cancellationtoken) The token the store must observe. #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask) The completion task; any result is discarded. ### CancellableWriteAsync\(CancellationToken\) Calls one **write** method of the store with the given token. ```csharp protected abstract ValueTask CancellableWriteAsync(CancellationToken cancellationToken) ``` #### Parameters `cancellationToken` [CancellationToken](https://learn.microsoft.com/dotnet/api/system.threading.cancellationtoken) The token the store must observe. #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask) The completion task. #### Remarks The write must be one [StoreCancellationContract.WroteAnythingAsync](/api/tracon.testing.contracts.storage/) can see. A write this contract cannot read back proves nothing about side effects, which is why [StoreCancellationContract.The_write_this_contract_checks_can_be_read_back](/api/tracon.testing.contracts.storage/) runs the same pair with a live token and requires the read to find it. ### CreateStoreAsync\(\) Produces an empty store for the test. ```csharp protected abstract ValueTask CreateStoreAsync() ``` #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask\-1) A store ready for use. ### DisposeAsync\(\) ```csharp public ValueTask DisposeAsync() ``` #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask) ### InitializeAsync\(\) Called immediately after the class has been created, before it is used. ```csharp public ValueTask InitializeAsync() ``` #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask) ### OnDisposeAsync\(\) Hook for a derived class to release its own resources. ```csharp protected virtual ValueTask OnDisposeAsync() ``` #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask) A completed task. ### The\_write\_this\_contract\_checks\_can\_be\_read\_back\(\) ```csharp [Fact] public Task The_write_this_contract_checks_can_be_read_back() ``` #### Returns [Task](https://learn.microsoft.com/dotnet/api/system.threading.tasks.task) ### WroteAnythingAsync\(\) Reports whether [StoreCancellationContract.CancellableWriteAsync](/api/tracon.testing.contracts.storage/) left anything behind. ```csharp protected abstract ValueTask WroteAnythingAsync() ``` #### Returns [ValueTask](https://learn.microsoft.com/dotnet/api/system.threading.tasks.valuetask\-1)<[bool](https://learn.microsoft.com/dotnet/api/system.boolean)\> [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) if the store holds any record the write would have created.