feat: add expiry_date property for Bolt11 model

included some tests for `dt` and `expiry_date` aswell

bolt11/types.py

@@ -107,6 +107,12 @@ def expiry(self) -> Optional[int]:
         tag = self.tags.get(TagChar.expire_time)
         return tag.data if tag else None
 
+    @property
+    def expiry_date(self) -> Optional[datetime]:
+        if not self.expiry:
+            return None
+        return datetime.fromtimestamp(self.date + self.expiry)
+
     @property
     def features(self) -> Optional[Features]:
         tag = self.tags.get(TagChar.features)

tests/test_bolt11_examples.py

@@ -1,3 +1,5 @@
+from datetime import datetime
+
 from bolt11.decode import decode
 from bolt11.encode import encode
 from bolt11.models.fallback import Fallback
@@ -127,7 +129,9 @@ def test_example_2(self):
         decoded = decode(ex["payment_request"])
         assert decoded.currency == ex["currency"]
         assert decoded.date == ex["date"]
+        assert decoded.dt == datetime.fromtimestamp(ex["date"])
         assert decoded.expiry == ex["expiry"]
+        assert decoded.expiry_date == datetime.fromtimestamp(ex["date"] + ex["expiry"])
         assert decoded.payment_hash == ex["payment_hash"]
         assert decoded.payment_secret == ex["payment_secret"]
         assert decoded.amount_msat == ex["amount_msat"]