feat: preimages for incoming payments, fundingsource saves preimage on create_invoice (#3085)

Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

tests/regtest/test_real_invoice.py

@@ -101,6 +101,8 @@ async def test_create_real_invoice(client, adminkey_headers_from, inkey_headers_
         balance = await get_node_balance_sats()
         assert balance - prev_balance == create_invoice.amount
 
+        assert payment_status.get("preimage") is not None
+
         # exit out of infinite loop
         raise FakeError()
 

tests/regtest/test_services_create_invoice.py

@@ -17,6 +17,8 @@ async def test_create_invoice(from_wallet):
         amount=1000,
         memo=description,
     )
+    assert payment.preimage
+
     invoice = decode(payment.bolt11)
     assert invoice.payment_hash == payment.payment_hash
     assert invoice.amount_msat == 1000000
@@ -33,6 +35,8 @@ async def test_create_internal_invoice(from_wallet):
     payment = await create_invoice(
         wallet_id=from_wallet.id, amount=1000, memo=description, internal=True
     )
+    assert payment.preimage
+
     invoice = decode(payment.bolt11)
     assert invoice.payment_hash == payment.payment_hash
     assert invoice.amount_msat == 1000000

tests/regtest/test_services_pay_invoice.py

@@ -19,6 +19,7 @@ async def test_services_pay_invoice(to_wallet, real_invoice):
     assert payment
     assert payment.status == PaymentState.SUCCESS
     assert payment.memo == description
+    assert payment.preimage
 
 
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