TimeoutStrategyOptions.TimeoutGenerator docs are incorrect

[wjrogers]

The XML comment on the TimeoutGenerator property says that returning TimeSpan.Zero means "use Timeout instead":

Polly/src/Polly.Core/Timeout/TimeoutStrategyOptions.cs

Lines 30 to 31 in 074a14d

	/// If generator returns a <see cref="TimeSpan"/> value that is less or equal to <see cref="TimeSpan.Zero"/>
	/// its value is ignored and <see cref="Timeout"/> is used instead. When generator is <see langword="null"/> the <see cref="Timeout"/> is used.

However, the code has no such logic. Any return value less than or equal to TimeSpan.Zero is treated as an infinite timeout:

Polly/src/Polly.Core/Timeout/TimeoutResilienceStrategy.cs

Lines 31 to 40 in a9008fa

	if (TimeoutGenerator is not null)
	{
	timeout = await TimeoutGenerator!(new TimeoutGeneratorArguments(context)).ConfigureAwait(context.ContinueOnCapturedContext);
	}
	if (!TimeoutUtil.ShouldApplyTimeout(timeout))
	{
	// do nothing
	return await callback(context, state).ConfigureAwait(context.ContinueOnCapturedContext);
	}

[peter-csala]

In case of Retry when the DelayGenerator returns null or zero or negative timestamp then it falls back to the Delay property based calculation.

Polly/src/Polly.Core/Retry/RetryResilienceStrategy.cs

Lines 67 to 76 in a9008fa

	var delay = RetryHelper.GetRetryDelay(BackoffType, UseJitter, attempt, BaseDelay, MaxDelay, ref retryState, _randomizer);
	if (DelayGenerator is not null)
	{
	var delayArgs = new RetryDelayGeneratorArguments<T>(context, outcome, attempt);
	if (await DelayGenerator(delayArgs).ConfigureAwait(false) is TimeSpan newDelay && RetryHelper.IsValidDelay(newDelay))
	{
	delay = newDelay;
	}
	}

Polly/src/Polly.Core/Retry/RetryHelper.cs

Line 14 in a9008fa

public static bool IsValidDelay(TimeSpan delay) => delay >= TimeSpan.Zero;

I assume we wanted to have something similar for the TimeoutStrategy.

---

BUT now it behaves in the following way:

• If only Timeout is defined then that is used
• If only TimeoutGenerator is defined then that is used
• If both Timeout and TimeoutGenerator are defined then Timeout is ignored.

[peter-csala]

@martincostello Can you close this issue please?

[martincostello]

Resolved by #2275.