mirror of
https://github.com/pezkuwichain/pezkuwi-subxt.git
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Adrian Catangiu
e7651cf41b
# Motivation (+testing)
### Enable easy `ForeignAssets` transfers using `pallet-xcm`
We had just previously added capabilities to teleport fees during
reserve-based transfers, but what about reserve-transferring fees when
needing to teleport some non-fee asset?
This PR aligns everything under either explicit reserve-transfer,
explicit teleport, or this new flexible `transfer_assets()` which can
mix and match as needed with fewer artificial constraints imposed to the
user.
This will enable, for example, a (non-system) parachain to teleport
their `ForeignAssets` assets to AssetHub while using DOT to pay fees.
(the assets are teleported - as foreign assets should from their owner
chain - while DOT used for fees can only be reserve-based transferred
between said parachain and AssetHub).
Added `xcm-emulator` tests for this scenario ^.
# Description
Reverts `(limited_)reserve_transfer_assets` to only allow reserve-based
transfers for all `assets` including fees.
Similarly `(limited_)teleport_assets` only allows teleports for all
`assets` including fees.
For complex combinations of asset transfers where assets and fees may
have different reserves or different reserve/teleport trust
configurations, users can use the newly added `transfer_assets()`
extrinsic which is more flexible in allowing more complex scenarios.
`assets` (excluding `fees`) must have same reserve location or otherwise
be teleportable to `dest`.
No limitations imposed on `fees`.
- for local reserve: transfer assets to sovereign account of destination
chain and forward a notification XCM to `dest` to mint and deposit
reserve-based assets to `beneficiary`.
- for destination reserve: burn local assets and forward a notification
to `dest` chain to withdraw the reserve assets from this chain's
sovereign account and deposit them to `beneficiary`.
- for remote reserve: burn local assets, forward XCM to reserve chain to
move reserves from this chain's SA to `dest` chain's SA, and forward
another XCM to `dest` to mint and deposit reserve-based assets to
`beneficiary`.
- for teleports: burn local assets and forward XCM to `dest` chain to
mint/teleport assets and deposit them to `beneficiary`.
## Review notes
Only around 500 lines are prod code (see `pallet_xcm/src/lib.rs`), the
rest of the PR is new tests and improving existing tests.
---------
Co-authored-by: command-bot <>
27 lines
1000 B
Plaintext
27 lines
1000 B
Plaintext
# Schema: Parity PR Documentation Schema (prdoc)
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# See doc at https://github.com/paritytech/prdoc
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title: Add new flexible `pallet_xcm::transfer_assets()` call/extrinsic
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doc:
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- audience: Builder
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description: |
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For complex combinations of asset transfers where assets and fees may have different reserves or
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different reserve/teleport trust configurations, users can use the newly added `transfer_assets()`
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extrinsic which is more flexible in allowing more complex scenarios.
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The new extrinsic enables, for example, a (non-system) parachain to teleport their `ForeignAssets`
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assets to `AssetHub` while using (reserve-based) `DOT` to pay fees.
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notes:
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- Now `(limited_)reserve_transfer_assets()` only allow reserve-based transfers for all assets
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including fees, similarly `(limited_)teleport_assets()` only allows teleports for all assets
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including fees.
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migrations:
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db: []
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runtime: []
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crates: pallet-xcm
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host_functions: []
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