fix(automatic-exchange-rates): skip bad AllRatesToday rows individually

A non-numeric, NaN or infinite value raised while parsing and threw away
the whole table. Each bad row is now skipped on its own.

Log a warning when a table has rows but none of a usable rate type, so a
bank with unknown types does not fail silently.

app/apps/currencies/exchange_rates/providers.py

@@ -739,10 +739,17 @@ class AllRatesTodayProvider(ExchangeRateProvider):
         """Reduce the table to one rate per pair, in both directions"""
         grouped = {}
         for row in rows:
-            if not isinstance(row, dict) or not row.get("value"):
+            if not isinstance(row, dict):
+                continue
+            try:
+                value = Decimal(str(row.get("value")))
+            except ArithmeticError:
+                continue
+            # A bad cell skips its own row, not the whole table
+            if not value.is_finite() or value <= 0:
                 continue
             pair = (row.get("base"), row.get("quote"))
-            grouped.setdefault(pair, {})[row.get("type")] = Decimal(str(row["value"]))
+            grouped.setdefault(pair, {})[row.get("type")] = value
 
         rates = {}
         for (base, quote), values in grouped.items():
@@ -756,11 +763,22 @@ class AllRatesTodayProvider(ExchangeRateProvider):
                     ),
                     None,
                 )
-            if rate is None or rate <= 0:
+            if rate is None:
+                logger.debug(
+                    f"AllRatesToday {self.bank}: no usable rate type for "
+                    f"{base}/{quote}, got {sorted(map(str, values))}"
+                )
                 continue
             rates[(base, quote)] = rate
             rates.setdefault((quote, base), self.invert_rate(rate))
 
+        if grouped and not rates:
+            types = sorted({str(t) for values in grouped.values() for t in values})
+            logger.warning(
+                f"AllRatesToday table for {self.bank} has no usable rate types, "
+                f"got {types}"
+            )
+
         return rates
 
     @staticmethod

app/apps/currencies/tests/test_allratestoday_provider.py

@@ -155,13 +155,35 @@ class AllRatesTodayProviderTests(TestCase):
 
         self.assertEqual(self._get_rates(rows, self.brl, self.usd), [])
 
+    def test_logs_a_table_without_usable_types(self):
+        self.usd.exchange_currency = self.brl
+        payload = {"rates": [_row("USD", "BRL", 5, "monthly_average")]}
+
+        with patch.object(
+            self.provider.session, "get", return_value=_response(payload)
+        ):
+            with self.assertLogs(
+                "apps.currencies.exchange_rates.providers", level="WARNING"
+            ) as logs:
+                self.provider.get_rates([self.usd], {self.brl})
+
+        self.assertIn("monthly_average", logs.output[0])
+
     def test_skips_pair_missing_from_the_table(self):
         rows = [_row("USD", "BRL", 5)]
 
         self.assertEqual(self._get_rates(rows, self.eur, self.usd), [])
 
     def test_ignores_zero_and_malformed_rows(self):
-        rows = ["nope", _row("USD", "BRL", 0), _row("EUR", "BRL", 6)]
+        rows = [
+            "nope",
+            _row("USD", "BRL", 0),
+            _row("USD", "BRL", "5,4"),
+            _row("USD", "BRL", None),
+            _row("USD", "BRL", "Infinity"),
+            _row("USD", "BRL", "NaN"),
+            _row("EUR", "BRL", 6),
+        ]
 
         rates = self._get_rates(rows, self.brl, self.eur)