public async Task AsyncOnce_runs_an_action_the_first_time_through()
{
var executions = 0;
var once = new AsyncOnce(() => { executions += 1; return(Task.CompletedTask); });
await once.ExecuteAsync();
Assert.Equal(1, executions);
}
public async Task AsyncOnce_indicates_poisoned_after_a_failure()
{
var once = new AsyncOnce(async() => { await Task.Yield(); throw new Exception(); });
Assert.False(once.Poisoned);
await Assert.ThrowsAsync <PoisonException>(() => once.ExecuteAsync());
Assert.True(once.Poisoned);
}
public async Task AsyncOnce_indicates_not_poisoned_for_success()
{
var once = new AsyncOnce(async() => { await Task.Yield(); });
Assert.False(once.Poisoned);
await once.ExecuteAsync();
Assert.False(once.Poisoned);
}
public async Task AsyncOnce_throws_if_the_action_throws()
{
var expected = new Exception();
var once = new AsyncOnce(async() => { await Task.Yield(); throw expected; });
var thrown = await Assert.ThrowsAsync <PoisonException>(
async() => await once.ExecuteAsync());
Assert.Same(thrown.InnerException, expected);
}
public async Task AsyncOnce_does_not_execute_actions_twice()
{
var executions = 0;
var once = new AsyncOnce(() => { executions += 1; return(Task.CompletedTask); });
await once.ExecuteAsync();
await once.ExecuteAsync();
Assert.Equal(1, executions);
}
public async Task AsyncOnce_throws_if_the_first_invocation_threw()
{
var invoked = false;
var expected = new Exception();
var once = new AsyncOnce(async() => { await Task.Yield(); invoked = true; throw expected; });
await Assert.ThrowsAsync <PoisonException>(async() => await once.ExecuteAsync());
Assert.True(invoked);
invoked = false;
var thrown = await Assert.ThrowsAsync <PoisonException>(
async() => await once.ExecuteAsync());
Assert.Same(thrown.InnerException, expected);
Assert.False(invoked);
}
