clean up tests

crates/cheatcodes/spec/src/vm.rs

@@ -523,11 +523,11 @@ interface Vm {
 
     /// Snapshot capture the gas usage of the last call by name from the callee perspective.
     #[cheatcode(group = Evm, safety = Unsafe)]
-    function snapshotGasLastCall(string calldata name) external;
+    function snapshotGasLastCall(string calldata name) external returns (uint256 gasUsed);
 
     /// Snapshot capture the gas usage of the last call by name in a group from the callee perspective.
     #[cheatcode(group = Evm, safety = Unsafe)]
-    function snapshotGasLastCall(string calldata group, string calldata name) external;
+    function snapshotGasLastCall(string calldata group, string calldata name) external returns (uint256 gasUsed);
 
     /// Start a snapshot capture of the current gas usage by name.
     /// The group name is derived from the contract name.

crates/cheatcodes/src/evm.rs

@@ -522,14 +522,14 @@ impl Cheatcode for readCallersCall {
 impl Cheatcode for snapshotValue_0Call {
     fn apply_stateful<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
         let Self { name, value } = self;
-        inner_create_value_snapshot(ccx, None, Some(name.clone()), value.to_string())
+        inner_value_snapshot(ccx, None, Some(name.clone()), value.to_string())
     }
 }
 
 impl Cheatcode for snapshotValue_1Call {
     fn apply_stateful<DB: DatabaseExt>(&self, ccx: &mut CheatsCtxt<DB>) -> Result {
         let Self { group, name, value } = self;
-        inner_create_value_snapshot(ccx, Some(group.clone()), Some(name.clone()), value.to_string())
+        inner_value_snapshot(ccx, Some(group.clone()), Some(name.clone()), value.to_string())
     }
 }
 
@@ -539,12 +539,7 @@ impl Cheatcode for snapshotGasLastCall_0Call {
         let Some(last_call_gas) = &ccx.state.gas_metering.last_call_gas else {
             bail!("no external call was made yet");
         };
-        inner_create_value_snapshot(
-            ccx,
-            None,
-            Some(name.clone()),
-            last_call_gas.gasTotalUsed.to_string(),
-        )
+        inner_last_gas_snapshot(ccx, None, Some(name.clone()), last_call_gas.gasTotalUsed)
     }
 }
 
@@ -554,11 +549,11 @@ impl Cheatcode for snapshotGasLastCall_1Call {
         let Some(last_call_gas) = &ccx.state.gas_metering.last_call_gas else {
             bail!("no external call was made yet");
         };
-        inner_create_value_snapshot(
+        inner_last_gas_snapshot(
             ccx,
             Some(group.clone()),
             Some(name.clone()),
-            last_call_gas.gasTotalUsed.to_string(),
+            last_call_gas.gasTotalUsed,
         )
     }
 }
@@ -787,7 +782,7 @@ fn inner_delete_state_snapshots<DB: DatabaseExt>(ccx: &mut CheatsCtxt<DB>) -> Re
     Ok(Default::default())
 }
 
-fn inner_create_value_snapshot<DB: DatabaseExt>(
+fn inner_value_snapshot<DB: DatabaseExt>(
     ccx: &mut CheatsCtxt<DB>,
     group: Option<String>,
     name: Option<String>,
@@ -805,6 +800,24 @@ fn inner_create_value_snapshot<DB: DatabaseExt>(
     Ok(Default::default())
 }
 
+fn inner_last_gas_snapshot<DB: DatabaseExt>(
+    ccx: &mut CheatsCtxt<DB>,
+    group: Option<String>,
+    name: Option<String>,
+    value: u64,
+) -> Result {
+    let cheatcodes = ccx.state.clone();
+    let group = group
+        .as_deref()
+        .unwrap_or(cheatcodes.config.running_contract.as_ref().expect("expected running contract"))
+        .to_string();
+    let name = name.as_deref().unwrap_or("default").to_string();
+
+    ccx.state.gas_snapshots.entry(group).or_default().insert(name, value.to_string());
+
+    Ok(value.abi_encode())
+}
+
 fn inner_start_gas_snapshot<DB: DatabaseExt>(
     ccx: &mut CheatsCtxt<DB>,
     group: Option<String>,

testdata/default/cheats/GasSnapshots.t.sol

@@ -7,50 +7,40 @@ import "cheats/Vm.sol";
 contract GasSnapshotTest is DSTest {
     Vm constant vm = Vm(HEVM_ADDRESS);
 
+    uint256 public slot0;
     Flare public flare;
-    uint256 public slot;
 
     function setUp() public {
         flare = new Flare();
     }
 
     function testGasExternal() public {
         vm.startSnapshotGas("testAssertGasExternal");
+        flare.run(1);
+        uint256 gasUsed = vm.stopSnapshotGas();
 
-        flare.update(2);
-
-        vm.stopSnapshotGas();
+        assertGt(gasUsed, 0);
     }
 
     function testGasInternal() public {
         vm.startSnapshotGas("testAssertGasInternalA");
-
-        slot = 1;
-
+        slot0 = 1;
         vm.stopSnapshotGas();
 
         vm.startSnapshotGas("testAssertGasInternalB");
-
-        slot = 2;
-
+        slot0 = 2;
         vm.stopSnapshotGas();
 
         vm.startSnapshotGas("testAssertGasInternalC");
-
-        slot = 0;
-
+        slot0 = 0;
         vm.stopSnapshotGas();
 
         vm.startSnapshotGas("testAssertGasInternalD");
-
-        slot = 1;
-
+        slot0 = 1;
         vm.stopSnapshotGas();
 
         vm.startSnapshotGas("testAssertGasInternalE");
-
-        slot = 2;
-
+        slot0 = 2;
         vm.stopSnapshotGas();
     }
 
@@ -146,22 +136,25 @@ contract GasSnapshotTest is DSTest {
     function testSnapshotGasLastCallName() public {
         flare.run(1);
 
-        vm.snapshotGasLastCall("testSnapshotGasName");
+        uint256 gasUsed = vm.snapshotGasLastCall("testSnapshotGasLastCallName");
+        assertGt(gasUsed, 0);
     }
 
     // Writes to `CustomGroup` group with `testSnapshotGas` name.
     function testSnapshotGasLastCallGroupName() public {
         flare.run(1);
 
-        vm.snapshotGasLastCall("CustomGroup", "testSnapshotGasGroupName");
+        uint256 gasUsed = vm.snapshotGasLastCall("CustomGroup", "testSnapshotGasLastCallGroupName");
+        assertGt(gasUsed, 0);
     }
 }
 
 contract GasComparisonTest is DSTest {
     Vm constant vm = Vm(HEVM_ADDRESS);
 
-    uint256 public slotA;
-    uint256 public slotB;
+    uint256 public slot0;
+    uint256 public slot1;
+
     uint256 public cachedGas;
 
     function testGasComparisonEmpty() public {
@@ -180,12 +173,12 @@ contract GasComparisonTest is DSTest {
     function testGasComparisonInternalCold() public {
         // Start a cheatcode snapshot.
         vm.startSnapshotGas("ComparisonGroup", "testGasComparisonInternalColdA");
-        slotA = 1;
+        slot0 = 1;
         uint256 a = vm.stopSnapshotGas();
 
         // Start a comparitive Solidity snapshot.
         _snapStart();
-        slotB = 1;
+        slot1 = 1;
         uint256 b = _snapEnd();
         vm.snapshotValue("ComparisonGroup", "testGasComparisonInternalColdB", b);
 
@@ -194,17 +187,16 @@ contract GasComparisonTest is DSTest {
 
     function testGasComparisonInternalWarm() public {
         // Warm up the cache.
-        slotA = 1;
-        slotB = 1;
+        slot0 = 1;
 
         // Start a cheatcode snapshot.
         vm.startSnapshotGas("ComparisonGroup", "testGasComparisonInternalWarmA");
-        slotA = 2;
+        slot0 = 2;
         uint256 a = vm.stopSnapshotGas();
 
         // Start a comparitive Solidity snapshot.
         _snapStart();
-        slotB = 2;
+        slot0 = 3;
         uint256 b = _snapEnd();
         vm.snapshotValue("ComparisonGroup", "testGasComparisonInternalWarmB", b);
 
@@ -213,19 +205,17 @@ contract GasComparisonTest is DSTest {
 
     function testGasComparisonExternal() public {
         // Warm up the cache.
-        TargetB targetA = new TargetB();
-        targetA.update(1);
-        TargetB targetB = new TargetB();
-        targetB.update(1);
+        TargetB target = new TargetB();
+        target.update(1);
 
         // Start a cheatcode snapshot.
         vm.startSnapshotGas("ComparisonGroup", "testGasComparisonExternalA");
-        targetA.update(2);
+        target.update(2);
         uint256 a = vm.stopSnapshotGas();
 
         // Start a comparitive Solidity snapshot.
         _snapStart();
-        targetB.update(2);
+        target.update(3);
         uint256 b = _snapEnd();
         vm.snapshotValue("ComparisonGroup", "testGasComparisonExternalB", b);
 
@@ -235,36 +225,32 @@ contract GasComparisonTest is DSTest {
     function testGasComparisonCreate() public {
         // Start a cheatcode snapshot.
         vm.startSnapshotGas("ComparisonGroup", "testGasComparisonCreateA");
-        new TargetEmptyA();
+        new TargetC();
         uint256 a = vm.stopSnapshotGas();
 
         // Start a comparitive Solidity snapshot.
         _snapStart();
-        new TargetEmptyB();
+        new TargetC();
         uint256 b = _snapEnd();
-
         vm.snapshotValue("ComparisonGroup", "testGasComparisonCreateB", b);
 
         vm.assertApproxEqAbs(a, b, 3);
     }
 
     function testGasComparisonNestedCalls() public {
         // Warm up the cache.
-        TargetA targetA = new TargetA();
-        targetA.update(1);
-        TargetA targetB = new TargetA();
-        targetB.update(1);
+        TargetA target = new TargetA();
+        target.update(1);
 
         // Start a cheatcode snapshot.
         vm.startSnapshotGas("ComparisonGroup", "testGasComparisonNestedCallsA");
-        targetA.update(2);
+        target.update(2);
         uint256 a = vm.stopSnapshotGas();
 
         // Start a comparitive Solidity snapshot.
         _snapStart();
-        targetB.update(2);
+        target.update(3);
         uint256 b = _snapEnd();
-
         vm.snapshotValue("ComparisonGroup", "testGasComparisonNestedCallsB", b);
 
         vm.assertApproxEqAbs(a, b, 2);
@@ -284,22 +270,13 @@ contract GasComparisonTest is DSTest {
 }
 
 contract Flare {
-    TargetA public target;
     bytes32[] public data;
 
-    constructor() {
-        target = new TargetA();
-    }
-
     function run(uint256 n_) public {
         for (uint256 i = 0; i < n_; i++) {
             data.push(keccak256(abi.encodePacked(i)));
         }
     }
-
-    function update(uint256 x_) public {
-        target.update(x_);
-    }
 }
 
 contract TargetA {
@@ -322,6 +299,4 @@ contract TargetB {
     }
 }
 
-contract TargetEmptyA {}
-
-contract TargetEmptyB {}
+contract TargetC {}

testdata/foundry.toml

@@ -1,5 +1,5 @@
 [profile.default]
-# solc = "0.8.18"
+solc = "0.8.18"
 block_base_fee_per_gas = 0
 block_coinbase = "0x0000000000000000000000000000000000000000"
 block_difficulty = 0