test: preserve quality and websocket evidence (#107)

Co-authored-by: Rogee <rogee@ipao.vip>

backend/scripts/quality_gate_test.py

@@ -2,6 +2,7 @@
 """Failure-injection checks for CI quality gates."""
 
 import json
+import os
 import subprocess
 import sys
 import tempfile
@@ -60,6 +61,22 @@ def gate(directory, budget=5, exit_code=0):
     )
 
 
+def assert_auditable_failure(result, directory, name, expected):
+    report = json.loads((directory / "report.json").read_text(encoding="utf-8"))
+    assert result.returncode != 0, f"{name} must fail"
+    assert report["status"] == "failed"
+    assert expected in report["failures"]
+    assert expected in result.stdout
+    print(result.stdout.strip())
+
+    if evidence := os.getenv("GOCHAT_QUALITY_DIR"):
+        target = Path(evidence)
+        target.mkdir(parents=True, exist_ok=True)
+        (target / f"{name}.json").write_text(
+            json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8"
+        )
+
+
 def main():
     with tempfile.TemporaryDirectory() as temp:
         directory = Path(temp)
@@ -97,10 +114,14 @@ def main():
                 {"Action": "fail", "Package": "github.com/gochat/gochat/internal/ws", "Test": "TestRelay"}
             ],
         )
-        assert gate(directory).returncode != 0, "failed test evidence must fail"
+        assert_auditable_failure(
+            gate(directory), directory, "action-fail", "test evidence contains 1 failed test events"
+        )
 
         write_fixtures(directory)
-        assert gate(directory, exit_code=2).returncode != 0, "non-zero go test status must fail"
+        assert_auditable_failure(
+            gate(directory, exit_code=2), directory, "nonzero-test-exit", "go test exited with 2"
+        )
 
         health = directory / "health.json"
         health.write_text(