fix all tests

cashu/wallet/transactions.py

@@ -79,9 +79,9 @@ async def _select_proofs_to_send_(
     async def _select_proofs_to_send(
         self, proofs: List[Proof], amount_to_send: int
     ) -> List[Proof]:
+        # check that enough spendable proofs exist
         if sum_proofs(proofs) < amount_to_send:
-            logger.trace("_select_proofs_to_send: not enough proofs to pay the amount.")
-            return []
+            raise Exception("balance too low.")
         logger.trace(
             f"_select_proofs_to_send – amount_to_send: {amount_to_send} – amounts we have: {amount_summary(proofs, self.unit)}"
         )

tests/test_mint_operations.py

@@ -177,14 +177,14 @@ async def test_split_with_input_less_than_outputs(wallet1: Wallet, ledger: Ledge
         wallet1.proofs, 10, set_reserved=False
     )
 
-    all_send_proofs = send_proofs + keep_proofs
+    too_many_proofs = send_proofs + send_proofs
 
-    # generate outputs for all proofs, not only the sent ones
+    # generate more outputs than inputs
     secrets, rs, derivation_paths = await wallet1.generate_n_secrets(
-        len(all_send_proofs)
+        len(too_many_proofs)
     )
     outputs, rs = wallet1._construct_outputs(
-        [p.amount for p in all_send_proofs], secrets, rs
+        [p.amount for p in too_many_proofs], secrets, rs
     )
 
     await assert_err(

tests/test_wallet_restore.py

@@ -370,7 +370,7 @@ async def test_restore_wallet_after_send_and_self_receive_nonquadratic_value(
     assert wallet3.balance == 0
     await wallet3.restore_promises_from_to(0, 20)
     box.add(wallet3.proofs)
-    assert wallet3.balance == 90
+    assert wallet3.balance == 84
     await wallet3.invalidate(wallet3.proofs, check_spendable=True)
     assert wallet3.balance == 64
 
@@ -389,6 +389,6 @@ async def test_restore_wallet_after_send_and_self_receive_nonquadratic_value(
     assert wallet3.proofs == []
     assert wallet3.balance == 0
     await wallet3.restore_promises_from_to(0, 50)
-    assert wallet3.balance == 118
+    assert wallet3.balance == 108
     await wallet3.invalidate(wallet3.proofs, check_spendable=True)
     assert wallet3.balance == 64