Allow assets to be forwarded to contracts on calls (#191)

fuels-abigen-macro/tests/harness.rs

@@ -8,7 +8,7 @@ use fuels_core::Token;
 use fuels_signers::util::test_helpers::{
     setup_address_and_coins, setup_test_provider, setup_test_provider_and_wallet,
 };
-use fuels_signers::{provider::Provider, LocalWallet};
+use fuels_signers::{provider::Provider, LocalWallet, Signer};
 use rand::rngs::StdRng;
 use rand::{Rng, SeedableRng};
 use sha2::{Digest, Sha256};
@@ -1363,8 +1363,22 @@ async fn test_amount_and_asset_forwarding() {
     // Trying to forward `amount` of a different asset_id.
     // Currently, if we use this asset_id in the forwarding, the VM will
     // return `AssetIdNotFound` if amount is larger than 0.
-    let asset: [u8; 32] = id.into();
-    let call_params = CallParameters::new(None, Some(AssetId::from(asset)));
+    let asset: [u8; 32] = id.clone().into();
+
+    // withdraw some tokens to wallet
+    let c_id = testfuelcoincontract_mod::ContractId { value: id.into() };
+    let address = wallet.address();
+    let address = testfuelcoincontract_mod::Address {
+        value: address.into(),
+    };
+    instance
+        .transfer_coins_to_output(1_000_000, c_id, address)
+        .append_variable_outputs(1)
+        .call()
+        .await
+        .unwrap();
+
+    let call_params = CallParameters::new(Some(0), Some(AssetId::from(asset)));
     let tx_params = TxParameters::new(None, Some(1_000_000), None);
 
     let response = instance

fuels-abigen-macro/tests/test_projects/token-ops/Forc.lock

@@ -1,21 +1,16 @@
 [[package]]
 name = 'core'
-source = 'git+http://github.com/FuelLabs/sway-lib-core?reference=master#30274cf817c1848e28f984c2e8703eb25e7a3a44'
-dependencies = []
-
-[[package]]
-name = 'core'
-source = 'git+https://github.com/FuelLabs/sway-lib-core?reference=master#30274cf817c1848e28f984c2e8703eb25e7a3a44'
+source = 'git+https://github.com/FuelLabs/sway-lib-core?branch=master#082bc8eb0616586ac0000825bfe6e9d47b0c713f'
 dependencies = []
 
 [[package]]
 name = 'std'
-source = 'git+http://github.com/FuelLabs/sway-lib-std?reference=master#7b973a638d5220228be616f1f89a249846001549'
-dependencies = ['core git+https://github.com/FuelLabs/sway-lib-core?reference=master#30274cf817c1848e28f984c2e8703eb25e7a3a44']
+source = 'git+https://github.com/FuelLabs/sway-lib-std?branch=master#dc036471ced326e41f076700c0501efc1b442455'
+dependencies = ['core git+https://github.com/FuelLabs/sway-lib-core?branch=master#082bc8eb0616586ac0000825bfe6e9d47b0c713f']
 
 [[package]]
 name = 'token-ops'
 dependencies = [
-    'core git+http://github.com/FuelLabs/sway-lib-core?reference=master#30274cf817c1848e28f984c2e8703eb25e7a3a44',
-    'std git+http://github.com/FuelLabs/sway-lib-std?reference=master#7b973a638d5220228be616f1f89a249846001549',
+    'core git+https://github.com/FuelLabs/sway-lib-core?branch=master#082bc8eb0616586ac0000825bfe6e9d47b0c713f',
+    'std git+https://github.com/FuelLabs/sway-lib-std?branch=master#dc036471ced326e41f076700c0501efc1b442455',
 ]

fuels-abigen-macro/tests/test_projects/token-ops/Forc.toml

@@ -5,5 +5,5 @@ license = "Apache-2.0"
 name = "token-ops"
 
 [dependencies]
-core = { git = "http://github.com/FuelLabs/sway-lib-core", branch = "master" }
-std = { git = "http://github.com/FuelLabs/sway-lib-std" , branch = "master"}
+core = { git = "https://github.com/FuelLabs/sway-lib-core", branch = "master" }
+std = { git = "https://github.com/FuelLabs/sway-lib-std" , branch = "master"}

fuels-abigen-macro/tests/test_projects/token-ops/src/main.sw

@@ -1,6 +1,6 @@
 contract;
 
-use std::{address::Address, context::balance_of_contract, context::msg_amount, contract_id::ContractId, token::*};
+use std::{address::Address, context::balance_of, context::msg_amount, contract_id::ContractId, token::*};
 
 abi TestFuelCoin {
     fn mint_coins(mint_amount: u64);
@@ -29,10 +29,10 @@ impl TestFuelCoin for Contract {
     }
 
     fn get_balance(target: ContractId, asset_id: ContractId) -> u64 {
-        balance_of_contract(target, asset_id)
+        balance_of(target, asset_id)
     }
 
     fn get_msg_amount() -> u64 {
         msg_amount()
     }
-}
+}

fuels-contract/src/contract.rs

@@ -171,17 +171,39 @@ impl Contract {
         );
         inputs.push(self_contract_input);
 
-        let spendables = wallet
+        let mut spendables = wallet
             .get_spendable_coins(&AssetId::default(), DEFAULT_COIN_AMOUNT as u64)
             .await
             .unwrap();
 
+        // add default asset change if any inputs are being spent
+        if !spendables.is_empty() {
+            let change_output = Output::change(wallet.address(), 0, AssetId::default());
+            outputs.push(change_output);
+        }
+
+        if call_parameters.asset_id != AssetId::default() {
+            let alt_spendables = wallet
+                .get_spendable_coins(&call_parameters.asset_id, call_parameters.amount)
+                .await
+                .unwrap();
+
+            // add alt change if inputs are being spent
+            if !alt_spendables.is_empty() {
+                let change_output = Output::change(wallet.address(), 0, call_parameters.asset_id);
+                outputs.push(change_output);
+            }
+
+            // add alt coins to inputs
+            spendables.extend(alt_spendables.into_iter());
+        }
+
         for coin in spendables {
             let input_coin = Input::coin(
                 UtxoId::from(coin.utxo_id),
                 coin.owner.into(),
                 coin.amount.0,
-                AssetId::default(),
+                coin.asset_id.into(),
                 0,
                 0,
                 vec![],
@@ -196,9 +218,6 @@ impl Contract {
         let self_contract_output = Output::contract(0, Bytes32::zeroed(), Bytes32::zeroed());
         outputs.push(self_contract_output);
 
-        let change_output = Output::change(wallet.address(), 0, AssetId::default());
-        outputs.push(change_output);
-
         // Add external contract IDs to Input/Output pair, if applicable.
         if let Some(external_contract_ids) = external_contracts {
             for (idx, external_contract_id) in external_contract_ids.iter().enumerate() {