test: preserve scalar receipts when optional shear probes fail

tests/validation/taylor_green/test_shear_wave.py

@@ -1012,6 +1012,14 @@ class ProbeTraceTests(unittest.TestCase):
         trace["values"] = [[1.0, 0.01, -0.02] * 24 for _ in sp.STEPS]
         size = sp.validate(trace)
         self.assertLess(size, sp.TRACE_MAX_BYTES)
+        final_trace = dict(trace, bytes=size)
+        self.assertEqual(size, len(json.dumps(final_trace, allow_nan=False).encode()))
+        self.assertEqual(sp.validate(final_trace), size)
+        with patch.object(sp, "TRACE_MAX_BYTES", size):
+            self.assertEqual(sp.validate(trace), size)
+        with patch.object(sp, "TRACE_MAX_BYTES", size - 1):
+            with self.assertRaises(ValueError):
+                sp.validate(trace)
         realistic = dict(trace, values=[[1.0000012345678901, 0.012345678901234567,
                                          -0.023456789012345678] * 24 for _ in sp.STEPS])
         self.assertLess(sp.validate(realistic), sp.TRACE_MAX_BYTES)
@@ -1108,6 +1116,7 @@ class ProbeTraceTests(unittest.TestCase):
         self.assertEqual(trace["steps"], list(sp.STEPS))
         self.assertEqual(len(trace["values"]), len(sp.STEPS))
         self.assertLessEqual(trace["bytes"], sp.TRACE_MAX_BYTES)
+        self.assertEqual(trace["bytes"], len(json.dumps(trace, allow_nan=False).encode()))
         self.assertEqual(trace["case"], [run_case.NESTED_SHEAR, 128, 3, "projected_linear"])
         self.assertEqual(len(rec["rows"]), 5)  # qualification samples preserved
         self.assertEqual(files, ["probe.json"])  # no field dumps
@@ -1122,3 +1131,34 @@ class ProbeTraceTests(unittest.TestCase):
         self.assertTrue(all(p["level"] == 0 for p in t512["probes"]))
         res = sp.residuals(t512)
         self.assertLess(abs(res[0][0][1]), 1e-14)  # exact field at t=0 at actual centers
+
+    def test_invalid_optional_trace_preserves_scalar_rows(self):
+        sp = self.probes
+        case = (128, 1, run_case.NESTED_SHEAR, "constant", [np.ones((128, 128), bool)])
+        baseline, _, _ = self.run_mocked(*case)
+        original = sp.sample
+        for bad in ([float("nan")] * 72, [float("inf")] * 72, [1.0],
+                    ZeroDivisionError("zero probe density")):
+            calls = []
+
+            def sample(arrays, probes):
+                calls.append(True)
+                if len(calls) == 2:  # probe-only step 1, before the next scalar save
+                    if isinstance(bad, Exception):
+                        raise bad
+                    return bad
+                return original(arrays, probes)
+
+            with self.subTest(bad=repr(bad)), patch.object(sp, "sample", side_effect=sample):
+                rec, counts, files = self.run_mocked(*case)
+            self.assertTrue(rec["completed"])
+            self.assertEqual(rec["rows"], baseline["rows"])
+            self.assertEqual(set(rec["probe_trace"]), {"error"})
+            self.assertEqual(len(calls), 2)  # no further probe sampling after rejection
+            self.assertEqual(counts[-1], 2048)
+            self.assertEqual(files, ["probe.json"])
+        with patch.object(sp, "TRACE_MAX_BYTES", 100):
+            rec, _, _ = self.run_mocked(*case)
+        self.assertTrue(rec["completed"])
+        self.assertEqual(rec["rows"], baseline["rows"])
+        self.assertIn("exceeds", rec["probe_trace"]["error"])