XCM WeightTrader: Swap Fee Asset for Native Asset (#1845)

Implements an XCM executor `WeightTrader`, facilitating fee payments in
any asset that can be exchanged for a native asset.

A few constraints need to be observed:
- `buy_weight` and `refund` operations must be atomic, as another weight
trader implementation might be attempted in case of failure.
- swap credit must be utilized since there isn’t an account to which an
asset of some class can be deposited with a guarantee to meet the
existential deposit requirement. Also, operating with credits enhances
the efficiency of the weight trader -
https://github.com/paritytech/polkadot-sdk/pull/1677

related PRs:
- (depends) https://github.com/paritytech/polkadot-sdk/pull/2031
- (depends) https://github.com/paritytech/polkadot-sdk/pull/1677
- (caused) https://github.com/paritytech/polkadot-sdk/pull/1847
- (caused) https://github.com/paritytech/polkadot-sdk/pull/1876

// DONE: impl `OnUnbalanced` for a `fungible/s` credit
// DONE: make the trader free from a concept of a native currency and
drop few fallible conversions. related issue -
https://github.com/paritytech/polkadot-sdk/issues/1842
// DONE: tests

---------

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
This commit is contained in:
Muharem
2024-01-16 15:34:48 +08:00
committed by GitHub
parent 4c4963a192
commit 2cb39f8dc9
25 changed files with 1769 additions and 861 deletions
@@ -16,6 +16,7 @@ codec = { package = "parity-scale-codec", version = "3.0.0", default-features =
frame-support = { path = "../../../../../substrate/frame/support", default-features = false }
frame-system = { path = "../../../../../substrate/frame/system", default-features = false }
pallet-assets = { path = "../../../../../substrate/frame/assets", default-features = false }
pallet-asset-conversion = { path = "../../../../../substrate/frame/asset-conversion", default-features = false }
pallet-balances = { path = "../../../../../substrate/frame/balances", default-features = false }
pallet-session = { path = "../../../../../substrate/frame/session", default-features = false }
sp-consensus-aura = { path = "../../../../../substrate/primitives/consensus/aura", default-features = false }
@@ -64,6 +65,7 @@ std = [
"cumulus-test-relay-sproof-builder/std",
"frame-support/std",
"frame-system/std",
"pallet-asset-conversion/std",
"pallet-assets/std",
"pallet-balances/std",
"pallet-collator-selection/std",