feat(forge): Implement vm.Sleep (#5519)

* implement vm sleep

* forge fmt

* remove println

abi/abi/HEVM.sol

@@ -217,3 +217,5 @@ stopMappingRecording()
 getMappingLength(address,bytes32)
 getMappingSlotAt(address,bytes32,uint256)
 getMappingKeyAndParentOf(address,bytes32)
+
+sleep(uint256)

evm/src/executor/inspector/cheatcodes/ext.rs

@@ -418,6 +418,14 @@ fn key_exists(json_str: &str, key: &str) -> Result {
     Ok(exists)
 }
 
+/// Sleeps for a given amount of milliseconds.
+fn sleep(milliseconds: &U256) -> Result {
+    let sleep_duration = std::time::Duration::from_millis(milliseconds.as_u64());
+    std::thread::sleep(sleep_duration);
+
+    Ok(Default::default())
+}
+
 #[instrument(level = "error", name = "ext", target = "evm::cheatcodes", skip_all)]
 pub fn apply(state: &mut Cheatcodes, call: &HEVMCalls) -> Option<Result> {
     Some(match call {
@@ -592,6 +600,7 @@ pub fn apply(state: &mut Cheatcodes, call: &HEVMCalls) -> Option<Result> {
         HEVMCalls::SerializeBytes1(inner) => {
             serialize_json(state, &inner.0, &inner.1, &array_str_to_str(&inner.2))
         }
+        HEVMCalls::Sleep(inner) => sleep(&inner.0),
         HEVMCalls::WriteJson0(inner) => write_json(state, &inner.0, &inner.1, None),
         HEVMCalls::WriteJson1(inner) => write_json(state, &inner.0, &inner.1, Some(&inner.2)),
         HEVMCalls::KeyExists(inner) => key_exists(&inner.0, &inner.1),

testdata/cheats/Sleep.t.sol

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: Unlicense
+pragma solidity 0.8.18;
+
+import "ds-test/test.sol";
+import "./Vm.sol";
+
+contract SleepTest is DSTest {
+    Vm constant vm = Vm(HEVM_ADDRESS);
+
+    function testSleep() public {
+        uint256 milliseconds = 1234;
+
+        string[] memory inputs = new string[](2);
+        inputs[0] = "date";
+        // OS X does not support precision more than 1 second
+        inputs[1] = "+%s000";
+
+        bytes memory res = vm.ffi(inputs);
+        uint256 start = vm.parseUint(string(res));
+
+        vm.sleep(milliseconds);
+
+        res = vm.ffi(inputs);
+        uint256 end = vm.parseUint(string(res));
+
+        // Limit precision to 1000 ms
+        assertGe(end - start, milliseconds / 1000 * 1000, "sleep failed");
+    }
+
+    /// forge-config: default.fuzz.runs = 10
+    function testSleepFuzzed(uint256 _milliseconds) public {
+        // Limit sleep time to 2 seconds to decrease test time
+        uint256 milliseconds = _milliseconds % 2000;
+
+        string[] memory inputs = new string[](2);
+        inputs[0] = "date";
+        // OS X does not support precision more than 1 second
+        inputs[1] = "+%s000";
+
+        bytes memory res = vm.ffi(inputs);
+        uint256 start = vm.parseUint(string(res));
+
+        vm.sleep(milliseconds);
+
+        res = vm.ffi(inputs);
+        uint256 end = vm.parseUint(string(res));
+
+        // Limit precision to 1000 ms
+        assertGe(end - start, milliseconds / 1000 * 1000, "sleep failed");
+    }
+}

testdata/cheats/Vm.sol

@@ -183,6 +183,9 @@ interface Vm {
     // Skips a test.
     function skip(bool) external;
 
+    // Sleeps for a given number of milliseconds.
+    function sleep(uint256) external;
+
     // Expects an error on next call
     function expectRevert() external;