fix(script): skip synthetic Tempo fees

.changelog/fix-tempo-script-setup-fees.md

@@ -0,0 +1,5 @@
+---
+forge: patch
+---
+
+Prevented synthetic Tempo script execution from charging TIP-20 gas fees.

crates/forge/tests/cli/script.rs

@@ -11,6 +11,7 @@ use anvil::{NodeConfig, spawn};
 use axum::{Router, body::Bytes as BodyBytes};
 use forge_script_sequence::ScriptSequence;
 use foundry_compilers::artifacts::EvmVersion;
+use foundry_evm::constants::CALLER;
 use foundry_test_utils::{
     ScriptOutcome, ScriptTester,
     rpc::{self, next_http_archive_rpc_url},
@@ -4805,6 +4806,54 @@ forgetest!(can_execute_script_command_with_tempo, |prj, cmd| {
         .assert_success();
 });
 
+forgetest_async!(tempo_script_runs_with_zero_fee_token_balance, |prj, cmd| {
+    foundry_test_utils::util::initialize(prj.root());
+    let script = prj.add_script(
+        "TempoScript.s.sol",
+        r#"
+import "forge-std/Script.sol";
+
+contract TempoScript is Script {
+    uint256 public value;
+
+    constructor() {
+        value = 1;
+    }
+
+    function setUp() external {
+        require(value == 1);
+        value = 2;
+    }
+
+    function run() external {
+        require(value == 2);
+        value = 3;
+    }
+}
+"#,
+    );
+    let (api, handle) = spawn(NodeConfig::test_tempo()).await;
+    let fee_token = address!("0x20c0000000000000000000000000000000000000");
+    let fee_manager = address!("0xfeec000000000000000000000000000000000000");
+    // Clear both balances so synthetic execution cannot accidentally succeed through fee
+    // accounting.
+    api.anvil_deal_tip20(CALLER, fee_token, U256::ZERO).await.unwrap();
+    api.anvil_deal_tip20(fee_manager, fee_token, U256::ZERO).await.unwrap();
+    cmd.arg("script").arg(script).args([
+        "--rpc-url",
+        &handle.http_endpoint(),
+        "--network",
+        "tempo",
+        "--tempo.fee-token",
+        "0x20c0000000000000000000000000000000000000",
+        "--with-gas-price",
+        "600000000",
+        "--block-gas-limit",
+        "18446744073709551615",
+    ]);
+    cmd.assert_success();
+});
+
 forgetest_async!(tempo_aa_script_broadcast_deploys_with_fee_token, |prj, cmd| {
     foundry_test_utils::util::initialize(prj.root());
     prj.add_source(

crates/script/src/lib.rs

@@ -1010,7 +1010,17 @@ impl<FEN: FoundryEvmNetwork> ScriptConfig<FEN> {
         target: ArtifactId,
         restricted: bool,
     ) -> Result<ScriptRunner<FEN>> {
-        self._get_runner(Some((known_contracts, script_wallets, target)), debug, restricted).await
+        let mut runner = self
+            ._get_runner(Some((known_contracts, script_wallets, target)), debug, restricted)
+            .await?;
+
+        // Script execution is synthetic. Keep the Tempo transaction context, but do not charge
+        // protocol fees for deploying or calling the local script contract.
+        if self.evm_opts.networks.is_tempo() {
+            runner.executor.evm_env_mut().cfg_env.disable_fee_charge = true;
+        }
+
+        Ok(runner)
     }
 
     async fn _get_runner(
@@ -1146,6 +1156,7 @@ mod tests {
             CallKind, CallTrace, CallTraceArena, CallTraceNode, SparsedTraceArena, TraceKind,
         },
     };
+    use semver::Version;
     use std::{fs, num::NonZeroU64, sync::LazyLock};
     use tempfile::tempdir;
     use tokio::sync::{Mutex, MutexGuard};
@@ -1935,6 +1946,51 @@ mod tests {
         assert_eq!(script.hardfork, Some(FoundryHardfork::Monad(MonadHardfork::MonadNine)));
     }
 
+    #[tokio::test(flavor = "multi_thread")]
+    async fn tempo_runner_fee_charge_matches_execution_context() {
+        let (_api, handle) = spawn(NodeConfig::test_tempo()).await;
+        let networks = NetworkConfigs::with_tempo();
+        let evm_opts = EvmOpts {
+            fork_url: Some(handle.http_endpoint()),
+            sender: handle.dev_accounts().next().unwrap(),
+            networks,
+            ..Default::default()
+        };
+        let config = Config { networks, ..Default::default() };
+        let mut script = ScriptConfig::<TempoEvmNetwork>::new(
+            config,
+            evm_opts,
+            false,
+            TempoOpts::default(),
+            None,
+        )
+        .await
+        .unwrap();
+
+        let rpc_runner = script._get_runner(None, false, false).await.unwrap();
+        assert!(!rpc_runner.executor.evm_env().cfg_env.disable_fee_charge);
+
+        let target = ArtifactId {
+            path: PathBuf::from("Script.json"),
+            name: "Script".to_string(),
+            source: PathBuf::from("Script.sol"),
+            version: Version::new(0, 8, 30),
+            build_id: String::new(),
+            profile: "default".to_string(),
+        };
+        let synthetic_runner = script
+            .get_runner_with_cheatcodes(
+                ContractsByArtifact::default(),
+                Wallets::new(Default::default(), None),
+                false,
+                target,
+                false,
+            )
+            .await
+            .unwrap();
+        assert!(synthetic_runner.executor.evm_env().cfg_env.disable_fee_charge);
+    }
+
     #[test]
     fn can_parse_shared_tempo_opts() {
         let args = ScriptArgs::parse_from([