feat: run extra fuzz rounds for new fuzz tests

Adds a new script that can run extra fuzz test iterations when
new fuzz tests are added. Can be used in CI or locally to make
sure that new fuzz tests aren't flaky.

.circleci/config.yml

@@ -530,6 +530,10 @@ jobs:
     docker:
       - image: <<pipeline.parameters.ci_builder_image>>
     resource_class: xlarge
+    parameters:
+      test_command:
+        type: string
+        default: "just test"
     steps:
       - checkout
       - check-changed:
@@ -545,7 +549,7 @@ jobs:
           working_directory: packages/contracts-bedrock
       - run:
           name: run tests
-          command: just test
+          command: << parameters.test_command >>
           environment:
             FOUNDRY_PROFILE: ci
           working_directory: packages/contracts-bedrock
@@ -1490,6 +1494,13 @@ workflows:
       - pnpm-monorepo:
           name: pnpm-monorepo
       - contracts-bedrock-tests
+          name: contracts-bedrock-tests
+          parameters:
+              test_command: "just test"
+      - contracts-bedrock-tests
+          name: contracts-bedrock-tests-extra-fuzz-runs
+          parameters:
+              test_command: "just test-extra-fuzz-runs"
       - contracts-bedrock-coverage
       - contracts-bedrock-checks:
           requires:

packages/contracts-bedrock/justfile

@@ -29,6 +29,10 @@ test-kontrol-no-build:
 test-rerun: build-go-ffi
   forge test --rerun -vvv
 
+# Run extra fuzz iterations for new fuzz tests.
+test-extra-fuzz-runs: build-go-ffi
+  ./scripts/testing/test-extra-fuzz-runs.sh
+
 genesis:
   forge script scripts/L2Genesis.s.sol:L2Genesis --sig 'runWithStateDump()'
 

packages/contracts-bedrock/scripts/testing/test-extra-fuzz-runs.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# This script is used to run extra fuzz test iterations on any fuzz tests that
+# have been newly added in a PR. We typically want to run extra fuzz iterations
+# when new tests are added to make sure that they are not flaky with some small
+# percentage of fuzz runs.
+
+# Set the number of fuzz runs to run
+# 350000 fuzz runs will guarantee that any test that fails 1% of the time with
+# the default 512 fuzz runs will fail 99.9% of the time (on average) inside of
+# this script.
+FUZZ_RUNS=${1:-350000}
+
+# show where the script failed in this next line!
+trap 'echo "Script failed at line $LINENO" && echo "Error: $BASH_COMMAND"' ERR
+
+# Get the contracts base directory
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+CONTRACTS_BASE=$(dirname "$(dirname "$SCRIPT_DIR")")
+
+# Determine if there are any new fuzz tests
+NEW_TEST_NAMES=$(git diff origin/develop...HEAD -- '*.sol' | grep -E '^\+.*function testFuzz_' | awk '{print $3}' | sed 's/.*function //; s/(.*//' || true)
+NEW_TEST_NAMES=$(echo "$NEW_TEST_NAMES" | tr '\n' ' ' | xargs)
+
+# Exit if no new fuzz tests are found
+if [ -z "$NEW_TEST_NAMES" ]; then
+    echo "No new fuzz tests found"
+    exit 0
+fi
+
+# Navigate to the contracts base directory
+cd "$CONTRACTS_BASE"
+
+# Run matching tests with extra fuzz runs
+forge test --match-test "${NEW_TEST_NAMES// /|}" --fuzz-runs $FUZZ_RUNS