release: bump version to 0.39.0

backend/tests/test_system_logs.py

@@ -162,3 +162,56 @@ def test_infer_log_level_prefers_leading_prefix_over_query_string():
     entry = system_logs.parse_text_log_entry(line)
 
     assert entry.level == "info"
+
+
+def test_parse_text_log_entry_does_not_promote_exception_context_to_error():
+    line = "websockets.exceptions.ConnectionClosedError: sent 1011 (internal error) keepalive ping timeout"
+
+    entry = system_logs.parse_text_log_entry(line)
+
+    assert entry.level is None
+
+
+def test_parse_text_log_entry_still_detects_explicit_error_prefix():
+    line = "ERROR: [Errno 98] Address already in use"
+
+    entry = system_logs.parse_text_log_entry(line)
+
+    assert entry.level == "error"
+
+
+def test_read_log_snapshot_strips_nul_bytes_from_file_lines(tmp_path: Path, monkeypatch):
+    log_path = tmp_path / "backend.log"
+    log_path.write_bytes(
+        (
+            b"INFO: service booted\n"
+            b"ERROR: bind failed\n"
+            + b"\x00" * 32
+            + b"2026-04-23 23:41:32 INFO service=backend message=request served\n"
+        )
+    )
+
+    monkeypatch.setattr(
+        system_logs,
+        "LOG_SOURCES",
+        {
+            "backend": system_logs.LogSource(
+                source_id="backend",
+                name="后端服务",
+                kind="file",
+                location=str(log_path),
+                description="测试文件日志",
+                category="service",
+            )
+        },
+    )
+
+    snapshot = system_logs.read_log_snapshot("backend", 50)
+
+    assert snapshot is not None
+    assert snapshot["line_count"] == 3
+    assert snapshot["lines"] == [
+        "INFO: service booted",
+        "ERROR: bind failed",
+        "2026-04-23 23:41:32 INFO service=backend message=request served",
+    ]