From b865e85de3c3b6c4b79e9b5bdae1aaf6ab639c48 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Tue, 5 Aug 2025 22:46:24 +0200
Subject: [PATCH] previous commit broke the tests because of the cfg business,
 see this commit's TODO

---
 pageserver/src/tenant.rs          | 14 ++++++++++----
 pageserver/src/tenant/timeline.rs |  2 +-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/pageserver/src/tenant.rs b/pageserver/src/tenant.rs
index 74fe7eb5d3..806e60e9ba 100644
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -9605,7 +9605,7 @@ mod tests {
             );
         });
 
-        // Test leasing same standby_horizon by different ID yields a fresh lease.
+        // Test leasing same LSN by different ID yields a fresh lease.
         // NB: leases are tracked by SystemTime, which is not monotonic, but we want to assert monotonicity of the lease below.
         // Sleep a second to make flakiness less likely.
         tokio::time::sleep(Duration::from_secs(1)).await;
@@ -9652,12 +9652,18 @@ mod tests {
         // Verify standby horizons did hold up GC
         //
 
-        // 0x20 was the lowest horizon
-        assert_eq!(*timeline.get_applied_gc_cutoff_lsn(), Lsn(0x20));
+        // 0x20 was the lowest horizon but
+        // TODO cfg(test) forces the new feature right now for coverage.
+        let expected_cutoff = if cfg!(test) || cfg!(feature = "testing") {
+            leases.iter().map(|(lsn, _)| *lsn).min().unwrap()
+        } else {
+            legacy
+        };
+        assert_eq!(*timeline.get_applied_gc_cutoff_lsn(), expected_cutoff);
 
         // Legacy propagation mechanism gets cleared by gc
         assert_eq!(timeline.standby_horizons.legacy(), None);
-        // Leases do not hold up GC
+        // Leases are unaffected.
         assert_eq!(timeline.standby_horizons.get_leases().len(), 4);
 
         assert_eq!(
diff --git a/pageserver/src/tenant/timeline.rs b/pageserver/src/tenant/timeline.rs
index 7e058639cb..36230699cc 100644
--- a/pageserver/src/tenant/timeline.rs
+++ b/pageserver/src/tenant/timeline.rs
@@ -6593,7 +6593,7 @@ impl Timeline {
         );
         let min_standby_horizon = if cfg!(test) || cfg!(feature = "testing") {
             // TODO: parametrize rust test / test suite over the feature flag?
-            // For now, test the new feature.
+            // For now, test the new feature. Fix this.
             min_standby_horizon.leases
         } else {
             match flag_evaluation_result.as_deref() {