feat: implement native fungible methods

pop-api/integration-tests/src/lib.rs

@@ -12,8 +12,8 @@ use scale::{Decode, Encode};
 use sp_runtime::{traits::Hash, AccountId32, BuildStorage, DispatchError};
 
 use pop_runtime_devnet::{
-	config::assets::TrustBackedAssetsInstance, Assets, Contracts, Runtime, RuntimeOrigin, System,
-	UNIT,
+	config::assets::TrustBackedAssetsInstance, Assets, Balances, Contracts, Runtime, RuntimeOrigin,
+	System, UNIT,
 };
 
 mod local_fungibles;

pop-api/integration-tests/src/local_fungibles.rs

@@ -304,6 +304,16 @@ fn total_supply_works() {
 	});
 }
 
+#[test]
+fn native_fungible_total_supply_works() {
+	new_test_ext().execute_with(|| {
+		let _ = env_logger::try_init();
+		let addr = instantiate(CONTRACT, INIT_VALUE, vec![]);
+		// Tokens in circulation.
+		assert_eq!(Balances::total_issuance(), total_supply(addr.clone(), 0));
+	});
+}
+
 #[test]
 fn balance_of_works() {
 	new_test_ext().execute_with(|| {

pop-api/src/v0/assets/balances.rs

@@ -0,0 +1,60 @@
+use crate::{
+	constants::BALANCES,
+	primitives::{AccountId, Balance},
+	Result, StatusCode,
+};
+use constants::*;
+use ink::env::chain_extension::ChainExtensionMethod;
+
+/// Helper method to build a dispatch call `ChainExtensionMethod` for native balances.
+///
+/// Parameters:
+/// - 'dispatchable': The index of the module dispatchable functions
+fn build_dispatch(dispatchable: u8) -> ChainExtensionMethod<(), (), (), false> {
+	crate::v0::build_dispatch(BALANCES, dispatchable)
+}
+
+/// Helper method to build a dispatch call `ChainExtensionMethod` for native balances.
+///
+/// Parameters:
+/// - 'state_query': The index of the runtime state query
+fn build_read_state(state_query: u8) -> ChainExtensionMethod<(), (), (), false> {
+	crate::v0::build_read_state(BALANCES, state_query)
+}
+
+mod constants {
+	/// - total_issuance
+	pub const TOTAL_ISSUANCE: u8 = 0;
+	/// - transfer_keep_alive
+	pub(super) const TRANSFER_KEEP_ALIVE: u8 = 3;
+}
+
+/// Returns the total supply for a native token
+///
+/// # Returns
+/// The total supply of the token, or an error if the operation fails.
+#[inline]
+pub fn total_issuance() -> Result<Balance> {
+	build_read_state(TOTAL_ISSUANCE)
+		.output::<Result<Balance>, true>()
+		.handle_error_code::<StatusCode>()
+		.call(&())
+}
+
+/// Transfers `value` amount of tokens from the caller's account to account `to`, with additional
+/// `data` in unspecified format.
+///
+/// # Arguments
+/// * `to` - The recipient account.
+/// * `value` - The number of native tokens to transfer.
+///
+/// # Returns
+/// Returns `Ok(())` if successful, or an error if the transfer fails.
+#[inline]
+pub fn transfer_keep_alive(target: AccountId, amount: Balance) -> Result<()> {
+	build_dispatch(TRANSFER_KEEP_ALIVE)
+		.input::<(AccountId, Balance)>()
+		.output::<Result<()>, true>()
+		.handle_error_code::<StatusCode>()
+		.call(&(target, amount))
+}

pop-api/src/v0/assets/fungibles.rs

@@ -1,4 +1,5 @@
 use crate::{
+	assets::balances,
 	constants::{ASSETS, BALANCES, FUNGIBLES},
 	primitives::{AccountId, AssetId, Balance},
 	Result, StatusCode,
@@ -74,11 +75,15 @@ mod constants {
 /// The total supply of the token, or an error if the operation fails.
 #[inline]
 pub fn total_supply(id: AssetId) -> Result<Balance> {
-	build_read_state(TOTAL_SUPPLY)
-		.input::<AssetId>()
-		.output::<Result<Balance>, true>()
-		.handle_error_code::<StatusCode>()
-		.call(&(id))
+	if id == 0 {
+		balances::total_issuance()
+	} else {
+		build_read_state(TOTAL_SUPPLY)
+			.input::<AssetId>()
+			.output::<Result<Balance>, true>()
+			.handle_error_code::<StatusCode>()
+			.call(&(id))
+	}
 }
 
 /// Returns the account balance for the specified `owner` for a given asset ID. Returns `0` if
@@ -130,11 +135,15 @@ pub fn allowance(id: AssetId, owner: AccountId, spender: AccountId) -> Result<Ba
 /// Returns `Ok(())` if successful, or an error if the transfer fails.
 #[inline]
 pub fn transfer(id: AssetId, target: AccountId, amount: Balance) -> Result<()> {
-	build_dispatch(TRANSFER)
-		.input::<(AssetId, AccountId, Balance)>()
-		.output::<Result<()>, true>()
-		.handle_error_code::<StatusCode>()
-		.call(&(id, target, amount))
+	if id == 0 {
+		balances::transfer_keep_alive(target, amount)
+	} else {
+		build_dispatch(TRANSFER)
+			.input::<(AssetId, AccountId, Balance)>()
+			.output::<Result<()>, true>()
+			.handle_error_code::<StatusCode>()
+			.call(&(id, target, amount))
+	}
 }
 
 /// Transfers `value` tokens on behalf of `from` to account `to` with additional `data`

pop-api/src/v0/assets/mod.rs

@@ -1,2 +1,4 @@
 #[cfg(feature = "fungibles")]
+mod balances;
+#[cfg(feature = "fungibles")]
 pub mod fungibles;