feat: unify asset_vault::remove_asset for all asset types

CHANGELOG.md

@@ -92,6 +92,7 @@
 - Renamed the `Authority` config value slot, expressed the authority kind as a MASM `enum Authority : u8`, and enforced the canonical config-word encoding on read ([#3209](https://github.com/0xMiden/protocol/pull/3209)).
 - Unified procedure ordering and document sender-based access control's authentication assumption in the `ownable2step` and `rbac` access control modules ([#3205](https://github.com/0xMiden/protocol/pull/3205)).
 - Refactor `asset_vault::add_asset` and `faucet::mint` to use a unified path for all asset types, in preparation of custom asset ([#3217](https://github.com/0xMiden/protocol/pull/3217)).
+- Refactor `asset_vault::remove_asset` and `faucet::burn` to use a unified path for all asset types, in preparation of custom assets ([#3078](https://github.com/0xMiden/protocol/issues/3078)).
 - [BREAKING] Updated `BlockHeader` to support multiple validator keys and added `ValidatorKeys` and `BlockSignatures` types ([#3174](https://github.com/0xMiden/protocol/pull/3174)).
 
 ### Fixes

crates/miden-protocol/asm/kernels/transaction-core/src/account_update.masm

@@ -889,8 +889,11 @@ proc compute_asset_delta
         cswapw
         # => [LESSER_ASSET_VALUE, GREATER_ASSET_VALUE, ASSET_ID, delta_op]
 
+        dupw.2 exec.asset::id_into_composition
+        # => [asset_composition, LESSER_ASSET_VALUE, GREATER_ASSET_VALUE, ASSET_ID, delta_op]
+
         # compute the delta as greater - lesser
-        dupw.2 exec.asset::split
+        exec.asset::split
         # => [DELTA_ASSET_VALUE, ASSET_ID, delta_op]
 
         swapw movup.8

crates/miden-protocol/asm/kernels/transaction-core/src/asset.masm

@@ -31,6 +31,7 @@ pub use {
     id_to_asset_class,
     id_into_asset_class,
     id_to_composition,
+    id_into_composition,
     load,
     store,
     validate_metadata,
@@ -251,16 +252,16 @@ pub proc merge
     # => [MERGED_ASSET_VALUE]
 end
 
-#! Computes OTHER_ASSET_VALUE - CURRENT_ASSET_VALUE for the asset identified by ASSET_ID.
+#! Computes OTHER_ASSET_VALUE - CURRENT_ASSET_VALUE for the asset with the given composition.
 #!
-#! WARNING: This procedure assumes both asset values belong to the asset identified by ASSET_ID
-#! and have already been validated.
+#! WARNING: This procedure assumes both asset values belong to the same asset and have already been
+#! validated. The `asset_composition` must be taken from the asset ID.
 #!
-#! Inputs:  [ASSET_ID, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
+#! Inputs:  [asset_composition, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
 #! Outputs: [SPLIT_ASSET_VALUE]
 #!
 #! Where:
-#! - ASSET_ID is the asset ID of the asset whose values are being split.
+#! - asset_composition is the asset composition of the asset whose values are being split.
 #! - CURRENT_ASSET_VALUE is the value subtracted from OTHER_ASSET_VALUE.
 #! - OTHER_ASSET_VALUE is the value being subtracted from.
 #! - SPLIT_ASSET_VALUE is OTHER_ASSET_VALUE - CURRENT_ASSET_VALUE.
@@ -270,19 +271,13 @@ end
 #! - the asset's composition is Custom (not yet supported).
 #! - the underlying split operation panics (see fungible_asset::split).
 pub proc split
-    exec.id_to_composition
-    # => [asset_composition, ASSET_ID, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
-
     dup neq.COMPOSITION_NONE assert.err=ERR_VAULT_SPLIT_COMPOSITION_NONE
-    # => [asset_composition, ASSET_ID, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
+    # => [asset_composition, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
 
     eq.COMPOSITION_FUNGIBLE
-    # => [is_fungible_asset, ASSET_ID, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
+    # => [is_fungible_asset, CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
 
     if.true
-        dropw
-        # => [CURRENT_ASSET_VALUE, OTHER_ASSET_VALUE]
-
         exec.fungible_asset::split
         # => [SPLIT_ASSET_VALUE]
     else