From 9b79d65f810a62248eb31d0f0699e2505d02835c Mon Sep 17 00:00:00 2001
From: Micah Villmow <4211002+mvillmow@users.noreply.github.com>
Date: Fri, 1 May 2026 22:20:07 +0000
Subject: [PATCH 1/2] test: fail prefix roundtrip when no traces are tested

---
 .../tests/test_roundtrip_hashes.py                | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py b/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
index aaa880bb1ad8..2f19ebb35cd2 100644
--- a/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
+++ b/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
@@ -97,6 +97,7 @@ def test_hash_roundtrip_direct(self):
             # Phase 2: Test roundtrip
             roundtrip_hasher = RollingHasher(block_size=DEFAULT_BLOCK_SIZE)
             mismatches = []
+            generation_failures = []
             tested = 0
 
             for i, trace in enumerate(traces):
@@ -113,6 +114,7 @@ def test_hash_roundtrip_direct(self):
                     )
                 except Exception as e:
                     print(f"  Trace {i}: Generation failed - {e}")
+                    generation_failures.append((i, str(e)))
                     continue
 
                 # Step 2: Re-encode text (simulates what server does)
@@ -142,6 +144,19 @@ def test_hash_roundtrip_direct(self):
 
             print(f"\nTested {tested} traces with hash_ids")
 
+            if tested == 0:
+                failure_details = ""
+                if generation_failures:
+                    preview = "; ".join(
+                        f"trace {i}: {error}"
+                        for i, error in generation_failures[:5]
+                    )
+                    failure_details = f" Generation failures: {preview}"
+                pytest.fail(
+                    "No traces were successfully tested for hash roundtrip."
+                    f"{failure_details}"
+                )
+
             # Report results
             if mismatches:
                 print(f"\nFound {len(mismatches)} hash mismatches:")

From 1348e271488b5667b493d46d4042fe0ce480573e Mon Sep 17 00:00:00 2001
From: Micah Villmow <4211002+mvillmow@users.noreply.github.com>
Date: Mon, 4 May 2026 16:50:09 +0000
Subject: [PATCH 2/2] test: format prefix roundtrip failure details

---
 .../prefix_data_generator/tests/test_roundtrip_hashes.py       | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py b/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
index 2f19ebb35cd2..3300617154ba 100644
--- a/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
+++ b/benchmarks/prefix_data_generator/tests/test_roundtrip_hashes.py
@@ -148,8 +148,7 @@ def test_hash_roundtrip_direct(self):
                 failure_details = ""
                 if generation_failures:
                     preview = "; ".join(
-                        f"trace {i}: {error}"
-                        for i, error in generation_failures[:5]
+                        f"trace {i}: {error}" for i, error in generation_failures[:5]
                     )
                     failure_details = f" Generation failures: {preview}"
                 pytest.fail(