Test/mint_add_verification_balance (#373)

* add verification balance

* verify input and outputs amounts before flow

* adjust tests

tests/test_mint_operations.py

@@ -8,6 +8,17 @@ from tests.conftest import SERVER_ENDPOINT
 from tests.helpers import pay_if_regtest
 
 
+async def assert_err(f, msg):
+    """Compute f() and expect an error message 'msg'."""
+    try:
+        await f
+    except Exception as exc:
+        if msg not in str(exc.args[0]):
+            raise Exception(f"Expected error: {msg}, got: {exc.args[0]}")
+        return
+    raise Exception(f"Expected error: {msg}, got no error")
+
+
 @pytest_asyncio.fixture(scope="function")
 async def wallet1(mint):
     wallet1 = await Wallet1.with_db(
@@ -58,6 +69,60 @@ async def test_split(wallet1: Wallet, ledger: Ledger):
     assert [p.amount for p in promises] == [p.amount for p in outputs]
 
 
+@pytest.mark.asyncio
+async def test_split_with_input_less_than_outputs(wallet1: Wallet, ledger: Ledger):
+    invoice = await wallet1.request_mint(64)
+    pay_if_regtest(invoice.bolt11)
+    await wallet1.mint(64, id=invoice.id)
+
+    keep_proofs, send_proofs = await wallet1.split_to_send(
+        wallet1.proofs, 10, set_reserved=False
+    )
+
+    all_send_proofs = send_proofs + keep_proofs
+
+    # generate outputs for all proofs, not only the sent ones
+    secrets, rs, derivation_paths = await wallet1.generate_n_secrets(
+        len(all_send_proofs)
+    )
+    outputs, rs = wallet1._construct_outputs(
+        [p.amount for p in all_send_proofs], secrets, rs
+    )
+
+    await assert_err(
+        ledger.split(proofs=send_proofs, outputs=outputs),
+        "inputs do not have same amount as outputs.",
+    )
+
+    # make sure we can still spend our tokens
+    keep_proofs, send_proofs = await wallet1.split(wallet1.proofs, 10)
+
+
+@pytest.mark.asyncio
+async def test_split_with_input_more_than_outputs(wallet1: Wallet, ledger: Ledger):
+    invoice = await wallet1.request_mint(128)
+    pay_if_regtest(invoice.bolt11)
+    await wallet1.mint(128, id=invoice.id)
+
+    inputs = wallet1.proofs
+
+    # less outputs than inputs
+    output_amounts = [8]
+    secrets, rs, derivation_paths = await wallet1.generate_n_secrets(
+        len(output_amounts)
+    )
+    outputs, rs = wallet1._construct_outputs(output_amounts, secrets, rs)
+
+    await assert_err(
+        ledger.split(proofs=inputs, outputs=outputs),
+        "inputs do not have same amount as outputs",
+    )
+
+    # make sure we can still spend our tokens
+    keep_proofs, send_proofs = await wallet1.split(inputs, 10)
+    print(keep_proofs, send_proofs)
+
+
 @pytest.mark.asyncio
 async def test_check_proof_state(wallet1: Wallet, ledger: Ledger):
     invoice = await wallet1.request_mint(64)