feat: fungible metadata amount utils

crates/yttrium/src/chain_abstraction/amount.rs

@@ -4,6 +4,7 @@ use alloy::primitives::{
 };
 
 #[derive(Debug)]
+#[cfg_attr(feature = "uniffi", derive(uniffi_macros::Record))]
 pub struct Amount {
     pub symbol: String,        // USDC, USD
     pub amount: U256,          // e.g. 40000, 4

crates/yttrium/src/chain_abstraction/api/fungible_price.rs

@@ -40,23 +40,8 @@ pub struct FungiblePriceItem {
     pub icon_url: String,
     pub price: f64,
     #[serde(
-        deserialize_with = "deserialize_unit",
-        serialize_with = "serialize_unit"
+        deserialize_with = "crate::utils::deserialize_unit",
+        serialize_with = "crate::utils::serialize_unit"
     )]
     pub decimals: Unit,
 }
-
-fn deserialize_unit<'de, D>(deserializer: D) -> Result<Unit, D::Error>
-where
-    D: serde::Deserializer<'de>,
-{
-    Unit::new(u8::deserialize(deserializer)?)
-        .ok_or(serde::de::Error::custom("Unit must be less than 77"))
-}
-
-fn serialize_unit<S>(unit: &Unit, serializer: S) -> Result<S::Ok, S::Error>
-where
-    S: serde::Serializer,
-{
-    serializer.serialize_u8(unit.get())
-}

crates/yttrium/src/chain_abstraction/api/route.rs

@@ -1,6 +1,7 @@
 use {
     super::Transaction,
-    alloy::primitives::{Address, U256},
+    crate::chain_abstraction::amount::Amount,
+    alloy::primitives::{utils::Unit, Address, U256},
     relay_rpc::domain::ProjectId,
     serde::{Deserialize, Serialize},
 };
@@ -33,8 +34,34 @@ pub struct FundingMetadata {
     pub chain_id: String,
     pub token_contract: Address,
     pub symbol: String,
+
+    // The amount that was sources (includes the bridging fee)
     pub amount: U256,
+
+    // The amount taken by the bridge as a fee
     pub bridging_fee: U256,
+
+    #[serde(
+        deserialize_with = "crate::utils::deserialize_unit",
+        serialize_with = "crate::utils::serialize_unit"
+    )]
+    #[serde(default = "default_unit")]
+    pub decimals: Unit,
+}
+
+// TODO remove default when Blockchain API is updated to provide this
+fn default_unit() -> Unit {
+    Unit::new(6).unwrap()
+}
+
+impl FundingMetadata {
+    pub fn to_amount(&self) -> Amount {
+        Amount::new(self.symbol.clone(), self.amount, self.decimals)
+    }
+
+    pub fn to_bridging_fee_amount(&self) -> Amount {
+        Amount::new(self.symbol.clone(), self.bridging_fee, self.decimals)
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]

crates/yttrium/src/chain_abstraction/tests.rs

@@ -1374,6 +1374,71 @@ async fn happy_path_full_dependency_on_route_ui_fields() {
     result.transactions[0].gas = U64::from(60000 /* 55437 */); // until Blockchain API estimates this
     result.transactions[1].gas = U64::from(140000 /* 107394 */); // until Blockchain API estimates this
 
+    assert_eq!(result.metadata.funding_from.len(), 1);
+    assert_eq!(result.metadata.funding_from.first().unwrap().symbol, "USDC");
+    assert_eq!(
+        result.metadata.funding_from.first().unwrap().decimals,
+        Unit::new(6).unwrap()
+    );
+    assert_eq!(
+        result
+            .metadata
+            .funding_from
+            .first()
+            .unwrap()
+            .clone()
+            .to_amount()
+            .symbol,
+        "USDC"
+    );
+    assert!(result
+        .metadata
+        .funding_from
+        .first()
+        .unwrap()
+        .to_amount()
+        .formatted
+        .ends_with(" USDC"));
+    println!(
+        "{}",
+        result.metadata.funding_from.first().unwrap().to_amount().formatted
+    );
+    assert!(result
+        .metadata
+        .funding_from
+        .first()
+        .unwrap()
+        .to_amount()
+        .formatted
+        .starts_with("1.5"));
+    assert!(result
+        .metadata
+        .funding_from
+        .first()
+        .unwrap()
+        .to_bridging_fee_amount()
+        .formatted
+        .starts_with("0."));
+    assert!(
+        result.metadata.funding_from.first().unwrap().amount <= required_amount
+    );
+    assert!(result.metadata.funding_from.first().unwrap().amount > send_amount);
+    assert!(
+        result.metadata.funding_from.first().unwrap().bridging_fee > U256::ZERO
+    );
+    assert!(
+        result.metadata.funding_from.first().unwrap().bridging_fee
+            < send_amount / U256::from(2)
+    );
+    assert_eq!(
+        result.metadata.funding_from.first().unwrap().chain_id,
+        source.bridge_token(&sources).params.chain.eip155_chain_id()
+    );
+    assert_eq!(
+        &result.metadata.funding_from.first().unwrap().token_contract,
+        source.bridge_token(&sources).token.address()
+    );
+
     let start = Instant::now();
     let route_ui_fields = client
         .get_route_ui_fields(

crates/yttrium/src/lib.rs

@@ -23,6 +23,7 @@ pub mod smart_accounts;
 pub mod test_helpers;
 pub mod transaction;
 pub mod user_operation;
+pub mod utils;
 
 #[cfg(test)]
 pub mod examples;

crates/yttrium/src/uniffi_compat.rs

@@ -1,4 +1,6 @@
-use alloy::primitives::{Address, Bytes, B256, U256, U64};
+use crate::chain_abstraction::amount::Amount;
+use crate::chain_abstraction::api::route::FundingMetadata;
+use alloy::primitives::{utils::Unit, Address, Bytes, B256, U256, U64};
 
 // TODO use https://mozilla.github.io/uniffi-rs/next/udl/remote_ext_types.html#remote-types when it's available
 
@@ -26,3 +28,20 @@ uniffi::custom_type!(B256, String, {
     try_lift: |val| Ok(val.parse()?),
     lower: |obj| obj.to_string(),
 });
+
+uniffi::custom_type!(Unit, u8, {
+    try_lift: |val| Ok(Unit::new(val).expect("Unit must be less than 77")),
+    lower: |obj| obj.get(),
+});
+
+#[cfg(feature = "uniffi")]
+#[uniffi::export]
+fn funding_metadata_to_amount(value: FundingMetadata) -> Amount {
+    value.to_amount()
+}
+
+#[cfg(feature = "uniffi")]
+#[uniffi::export]
+fn funding_metadata_to_bridging_fee_amount(value: FundingMetadata) -> Amount {
+    value.to_bridging_fee_amount()
+}

crates/yttrium/src/utils.rs

@@ -0,0 +1,17 @@
+use alloy::primitives::utils::Unit;
+use serde::Deserialize;
+
+pub fn deserialize_unit<'de, D>(deserializer: D) -> Result<Unit, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    Unit::new(u8::deserialize(deserializer)?)
+        .ok_or(serde::de::Error::custom("Unit must be less than 77"))
+}
+
+pub fn serialize_unit<S>(unit: &Unit, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    serializer.serialize_u8(unit.get())
+}