public static async Task TestConcurrentAccountDeletion()
{
// Initialize the mock in-memory DB and account manager.
var dbCollection = new InMemoryDbCollection();
var accountManager = new AccountManager(dbCollection);
// Create some dummy data.
string accountName = "MyAccount";
string accountPayload = "...";
// Create the account and wait for it to complete.
await accountManager.CreateAccount(accountName, accountPayload);
// Call DeleteAccount twice without awaiting, which makes both methods run
// asynchronously with each other.
var task1 = accountManager.DeleteAccount(accountName);
var task2 = accountManager.DeleteAccount(accountName);
// Then wait both requests to complete.
await Task.WhenAll(task1, task2);
// Finally, assert that only one of the two requests succeeded and the other
// failed. Note that we do not know which one of the two succeeded as the
// requests ran concurrently (this is why we use an exclusive OR).
Assert.True(task1.Result ^ task2.Result);
}
public static async Task TestAccountCreation()
{
// Initialize the mock in-memory DB and account manager.
var dbCollection = new InMemoryDbCollection();
var accountManager = new AccountManager(dbCollection);
// Create some dummy data.
string accountName = "MyAccount";
string accountPayload = "...";
// Create the account, it should complete successfully and return true.
var result = await accountManager.CreateAccount(accountName, accountPayload);
Assert.True(result);
// Create the same account again. The method should return false this time.
result = await accountManager.CreateAccount(accountName, accountPayload);
Assert.False(result);
}
public static async Task TestConcurrentAccountCreationAndDeletion()
{
// Initialize the mock in-memory DB and account manager.
var dbCollection = new InMemoryDbCollection();
var accountManager = new AccountManager(dbCollection);
// Create some dummy data.
string accountName = "MyAccount";
string accountPayload = "...";
// Call CreateAccount and DeleteAccount without awaiting, which makes both
// methods run asynchronously with each other.
var createTask = accountManager.CreateAccount(accountName, accountPayload);
var deleteTask = accountManager.DeleteAccount(accountName);
// Then wait both requests to complete.
await Task.WhenAll(createTask, deleteTask);
// The CreateAccount request will always succeed, no matter what. The DeleteAccount
// may or may not succeed depending on if it finds the account already created or
// not created while executing concurrently with the CreateAccount request.
Assert.True(createTask.Result);
if (!deleteTask.Result)
{
// The DeleteAccount request didn't find the account and failed as expected.
// We assert that the account payload is still available.
string fetchedAccountPayload = await accountManager.GetAccount(accountName);
Assert.Equal(accountPayload, fetchedAccountPayload);
}
else
{
// If CreateAccount and DeleteAccount both returned true, then the account
// must have been created before the deletion happened.
// We assert that the payload is not available, as the account was deleted.
string fetchedAccountPayload = await accountManager.GetAccount(accountName);
Assert.Null(fetchedAccountPayload);
}
}