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pezkuwi-subxt/polkadot/xcm/procedural/tests/builder_pattern.rs
T
Francisco Aguirre b3841b6b71 Different XCM builders, default one requires fee payment (#2253)
Adding on top of the new builder pattern for creating XCM programs, I'm
adding some more APIs:

```rust
let paying_fees: Xcm<()> = Xcm::builder() // Only allow paying for fees
  .withdraw_asset() // First instruction has to load the holding register
  .buy_execution() // Second instruction has to be `buy_execution`
  .build();

let paying_fees_invalid: Xcm<()> = Xcm::builder()
  .withdraw_asset()
  .build(); // Invalid, need to pay for fees

let not_paying_fees: Xcm<()> = Xcm::builder_unpaid()
  .unpaid_execution() // Needed
  .withdraw_asset()
  .deposit_asset()
  .build();

let all_goes: Xcm<()> = Xcm::builder_unsafe() // You can do anything
  .withdraw_asset()
  .deposit_asset()
  .build();
```

The invalid bits are because the methods don't even exist on the types
that you'd want to call them on.

---------

Co-authored-by: command-bot <>
2023-11-21 16:09:40 +01:00

82 lines
2.8 KiB
Rust

// Copyright (C) Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Polkadot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! Test the methods generated by the Builder derive macro.
//! Tests directly on the actual Xcm struct and Instruction enum.
use xcm::latest::prelude::*;
#[test]
fn builder_pattern_works() {
let asset: MultiAsset = (Here, 100u128).into();
let beneficiary: MultiLocation = AccountId32 { id: [0u8; 32], network: None }.into();
let message: Xcm<()> = Xcm::builder()
.receive_teleported_asset(asset.clone().into())
.buy_execution(asset.clone(), Unlimited)
.deposit_asset(asset.clone().into(), beneficiary)
.build();
assert_eq!(
message,
Xcm(vec![
ReceiveTeleportedAsset(asset.clone().into()),
BuyExecution { fees: asset.clone(), weight_limit: Unlimited },
DepositAsset { assets: asset.into(), beneficiary },
])
);
}
#[test]
fn default_builder_requires_buy_execution() {
let asset: MultiAsset = (Here, 100u128).into();
let beneficiary: MultiLocation = AccountId32 { id: [0u8; 32], network: None }.into();
// This is invalid, since it doesn't pay for fees.
// This is enforced by the runtime, because the build() method doesn't exist
// on the resulting type.
// let message: Xcm<()> = Xcm::builder()
// .withdraw_asset(asset.clone().into())
// .deposit_asset(asset.into(), beneficiary)
// .build();
// To be able to do that, we need to use the explicitly unpaid variant
let message: Xcm<()> = Xcm::builder_unpaid()
.unpaid_execution(Unlimited, None)
.withdraw_asset(asset.clone().into())
.deposit_asset(asset.clone().into(), beneficiary)
.build(); // This works
assert_eq!(
message,
Xcm(vec![
UnpaidExecution { weight_limit: Unlimited, check_origin: None },
WithdrawAsset(asset.clone().into()),
DepositAsset { assets: asset.clone().into(), beneficiary },
])
);
// The other option doesn't have any limits whatsoever, so it should
// only be used when you really know what you're doing.
let message: Xcm<()> = Xcm::builder_unsafe()
.withdraw_asset(asset.clone().into())
.deposit_asset(asset.clone().into(), beneficiary)
.build();
assert_eq!(
message,
Xcm(vec![
WithdrawAsset(asset.clone().into()),
DepositAsset { assets: asset.clone().into(), beneficiary },
])
);
}