perf(invariant): do not include reverts in counterexample (#8459)

Author: grandizzy

crates/evm/evm/src/executors/invariant/result.rs

@@ -147,6 +147,10 @@ pub(crate) fn can_continue(
             invariant_data.failures.error = Some(InvariantFuzzError::Revert(case_data));
 
             return Ok(RichInvariantResults::new(false, None));
+        } else if call_result.reverted {
+            // If we don't fail test on revert then remove last reverted call from inputs.
+            // This improves shrinking performance as irrelevant calls won't be checked again.
+            invariant_run.inputs.pop();
         }
     }
     Ok(RichInvariantResults::new(true, call_results))

crates/forge/tests/it/invariant.rs

@@ -676,3 +676,21 @@ async fn test_invariant_selectors_weight() {
         )]),
     )
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_no_reverts_in_counterexample() {
+    let filter =
+        Filter::new(".*", ".*", ".*fuzz/invariant/common/InvariantSequenceNoReverts.t.sol");
+    let mut runner = TEST_DATA_DEFAULT.runner();
+    runner.test_options.invariant.fail_on_revert = false;
+    // Use original counterexample to test sequence len.
+    runner.test_options.invariant.shrink_run_limit = 0;
+
+    match get_counterexample!(runner, &filter) {
+        CounterExample::Single(_) => panic!("CounterExample should be a sequence."),
+        CounterExample::Sequence(sequence) => {
+            // ensure original counterexample len is 10 (even without shrinking)
+            assert_eq!(sequence.len(), 10);
+        }
+    };
+}

testdata/default/fuzz/invariant/common/InvariantSequenceNoReverts.t.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.13;
+
+import "ds-test/test.sol";
+
+contract SequenceNoReverts {
+    uint256 public count;
+
+    function work(uint256 x) public {
+        require(x % 2 != 0);
+        count++;
+    }
+}
+
+contract SequenceNoRevertsTest is DSTest {
+    SequenceNoReverts target;
+
+    function setUp() public {
+        target = new SequenceNoReverts();
+    }
+
+    function invariant_no_reverts() public view {
+        require(target.count() < 10, "condition met");
+    }
+}