nutshell/tests/test_mint.py

from typing import List

import pytest

from cashu.core.base import BlindedMessage, Proof
from cashu.core.crypto.b_dhke import step1_alice
from cashu.core.helpers import calculate_number_of_blank_outputs
from cashu.core.settings import settings
from cashu.mint.ledger import Ledger


async def assert_err(f, msg):
    """Compute f() and expect an error message 'msg'."""
    try:
        await f
    except Exception as exc:
        assert exc.args[0] == msg, Exception(
            f"Expected error: {msg}, got: {exc.args[0]}"
        )


def assert_amt(proofs: List[Proof], expected: int):
    """Assert amounts the proofs contain."""
    assert [p.amount for p in proofs] == expected


@pytest.mark.asyncio
async def test_pubkeys(ledger: Ledger):
    assert ledger.keyset.public_keys
    assert (
        ledger.keyset.public_keys[1].serialize().hex()
        == "03190ebc0c3e2726a5349904f572a2853ea021b0128b269b8b6906501d262edaa8"
    )
    assert (
        ledger.keyset.public_keys[2 ** (settings.max_order - 1)].serialize().hex()
        == "032dc008b88b85fdc2301a499bfaaef774c191a6307d8c9434838fc2eaa2e48d51"
    )


@pytest.mark.asyncio
async def test_privatekeys(ledger: Ledger):
    assert ledger.keyset.private_keys
    assert (
        ledger.keyset.private_keys[1].serialize()
        == "67de62e1bf8b5ccf88dbad6768b7d13fa0f41433b0a89caf915039505f2e00a7"
    )
    assert (
        ledger.keyset.private_keys[2 ** (settings.max_order - 1)].serialize()
        == "3b1340c703b02028a11025302d2d9e68d2a6dd721ab1a2770f0942d15eacb8d0"
    )


@pytest.mark.asyncio
async def test_keysets(ledger: Ledger):
    assert len(ledger.keysets.keysets)
    assert len(ledger.keysets.get_ids())
    assert ledger.keyset.id == "1cCNIAZ2X/w1"


@pytest.mark.asyncio
async def test_get_keyset(ledger: Ledger):
    keyset = ledger.get_keyset()
    assert isinstance(keyset, dict)
    assert len(keyset) == settings.max_order


@pytest.mark.asyncio
async def test_mint(ledger: Ledger):
    blinded_messages_mock = [
        BlindedMessage(
            amount=8,
            B_="02634a2c2b34bec9e8a4aba4361f6bf202d7fa2365379b0840afe249a7a9d71239",
        )
    ]
    promises = await ledger.mint(blinded_messages_mock)
    assert len(promises)
    assert promises[0].amount == 8
    assert (
        promises[0].C_
        == "037074c4f53e326ee14ed67125f387d160e0e729351471b69ad41f7d5d21071e15"
    )


@pytest.mark.asyncio
async def test_mint_invalid_blinded_message(ledger: Ledger):
    blinded_messages_mock_invalid_key = [
        BlindedMessage(
            amount=8,
            B_="02634a2c2b34bec9e8a4aba4361f6bff02d7fa2365379b0840afe249a7a9d71237",
        )
    ]
    await assert_err(
        ledger.mint(blinded_messages_mock_invalid_key), "invalid public key"
    )


@pytest.mark.asyncio
async def test_generate_promises(ledger: Ledger):
    blinded_messages_mock = [
        BlindedMessage(
            amount=8,
            B_="02634a2c2b34bec9e8a4aba4361f6bf202d7fa2365379b0840afe249a7a9d71239",
        )
    ]
    promises = await ledger._generate_promises(blinded_messages_mock)
    assert (
        promises[0].C_
        == "037074c4f53e326ee14ed67125f387d160e0e729351471b69ad41f7d5d21071e15"
    )
    assert promises[0].amount == 8

    # DLEQ proof present
    assert promises[0].dleq
    assert promises[0].dleq.s
    assert promises[0].dleq.e


@pytest.mark.asyncio
async def test_generate_change_promises(ledger: Ledger):
    # Example slightly adapted from NUT-08 because we want to ensure the dynamic change
    # token amount works: `n_blank_outputs != n_returned_promises != 4`.
    invoice_amount = 100_000
    fee_reserve = 2_000
    total_provided = invoice_amount + fee_reserve
    actual_fee_msat = 100_000

    expected_returned_promises = 7  # Amounts = [4, 8, 32, 64, 256, 512, 1024]
    expected_returned_fees = 1900

    n_blank_outputs = calculate_number_of_blank_outputs(fee_reserve)
    blinded_msgs = [step1_alice(str(n)) for n in range(n_blank_outputs)]
    outputs = [
        BlindedMessage(amount=1, B_=b.serialize().hex()) for b, _ in blinded_msgs
    ]

    promises = await ledger._generate_change_promises(
        total_provided, invoice_amount, actual_fee_msat, outputs
    )

    assert len(promises) == expected_returned_promises
    assert sum([promise.amount for promise in promises]) == expected_returned_fees


@pytest.mark.asyncio
async def test_generate_change_promises_legacy_wallet(ledger: Ledger):
    # Check if mint handles a legacy wallet implementation (always sends 4 blank
    # outputs) as well.
    invoice_amount = 100_000
    fee_reserve = 2_000
    total_provided = invoice_amount + fee_reserve
    actual_fee_msat = 100_000

    expected_returned_promises = 4  # Amounts = [64, 256, 512, 1024]
    expected_returned_fees = 1856

    n_blank_outputs = 4
    blinded_msgs = [step1_alice(str(n)) for n in range(n_blank_outputs)]
    outputs = [
        BlindedMessage(amount=1, B_=b.serialize().hex()) for b, _ in blinded_msgs
    ]

    promises = await ledger._generate_change_promises(
        total_provided, invoice_amount, actual_fee_msat, outputs
    )

    assert len(promises) == expected_returned_promises
    assert sum([promise.amount for promise in promises]) == expected_returned_fees


@pytest.mark.asyncio
async def test_generate_change_promises_returns_empty_if_no_outputs(ledger: Ledger):
    invoice_amount = 100_000
    fee_reserve = 1_000
    total_provided = invoice_amount + fee_reserve
    actual_fee_msat = 100_000
    outputs = None

    promises = await ledger._generate_change_promises(
        total_provided, invoice_amount, actual_fee_msat, outputs
    )
    assert len(promises) == 0