Merge pull request #3713 from TheBlueMatt/2025-04-probing-diversity-test

Update `probes_for_diversity` to test datapoint time updating

Author: tnull

lightning/src/routing/scoring.rs

@@ -1556,6 +1556,7 @@ DirectedChannelLiquidity<L, HT, T> {
 				chan_descr, existing_max_msat, amount_msat);
 		}
 		self.update_history_buckets(0, duration_since_epoch);
+		*self.last_datapoint_time = duration_since_epoch;
 	}
 
 	/// Adjusts the channel liquidity balance bounds when failing to route `amount_msat` downstream.
@@ -1571,6 +1572,7 @@ DirectedChannelLiquidity<L, HT, T> {
 				chan_descr, existing_min_msat, amount_msat);
 		}
 		self.update_history_buckets(0, duration_since_epoch);
+		*self.last_datapoint_time = duration_since_epoch;
 	}
 
 	/// Adjusts the channel liquidity balance bounds when successfully routing `amount_msat`.
@@ -1580,6 +1582,7 @@ DirectedChannelLiquidity<L, HT, T> {
 		let max_liquidity_msat = self.max_liquidity_msat().checked_sub(amount_msat).unwrap_or(0);
 		log_debug!(logger, "Subtracting {} from max liquidity of {} (setting it to {})", amount_msat, chan_descr, max_liquidity_msat);
 		self.set_max_liquidity_msat(max_liquidity_msat, duration_since_epoch);
+		*self.last_datapoint_time = duration_since_epoch;
 		self.update_history_buckets(amount_msat, duration_since_epoch);
 	}
 
@@ -1603,7 +1606,6 @@ DirectedChannelLiquidity<L, HT, T> {
 			*self.max_liquidity_offset_msat = 0;
 		}
 		*self.last_updated = duration_since_epoch;
-		*self.last_datapoint_time = duration_since_epoch;
 	}
 
 	/// Adjusts the upper bound of the channel liquidity balance in this direction.
@@ -1613,7 +1615,6 @@ DirectedChannelLiquidity<L, HT, T> {
 			*self.min_liquidity_offset_msat = 0;
 		}
 		*self.last_updated = duration_since_epoch;
-		*self.last_datapoint_time = duration_since_epoch;
 	}
 }
 
@@ -4161,21 +4162,24 @@ mod tests {
 			short_channel_id: 42,
 		});
 
-		// Apply some update to set the last-update time to now
-		scorer.payment_path_failed(&payment_path_for_amount(1000), 42, Duration::ZERO);
+		// Initialize the state for channel 42
+		scorer.payment_path_failed(&payment_path_for_amount(500), 42, Duration::ZERO);
+
+		// Apply an update to set the last-update time to 1 second
+		scorer.payment_path_failed(&payment_path_for_amount(500), 42, Duration::from_secs(1));
 
 		// If no time has passed, we get the full probing_diversity_penalty_msat
 		assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &params), 1_000_000);
 
 		// As time passes the penalty decreases.
-		scorer.time_passed(Duration::from_secs(1));
+		scorer.time_passed(Duration::from_secs(2));
 		assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &params), 999_976);
 
-		scorer.time_passed(Duration::from_secs(2));
+		scorer.time_passed(Duration::from_secs(3));
 		assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &params), 999_953);
 
 		// Once we've gotten halfway through the day our penalty is 1/4 the configured value.
-		scorer.time_passed(Duration::from_secs(86400/2));
+		scorer.time_passed(Duration::from_secs(86400/2 + 1));
 		assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &params), 250_000);
 	}
 }