Fix fuzzer-runner missing transitive dependency and add tests (#459)

* Use openlit <1.36.6

Openlit >=1.36.6 has a bug with langgraph instrumentation.

Also add a test to seed-gen for when openlit is enabled

* Link to issue

* Fix CoverageBot.run_task and add test cases

* Add setuptools as an explicit dependency

This is because a transitive dependency via clusterfuzz depends on it

* Appease ruff

Author: reytchison

fuzzer_runner/pyproject.toml

@@ -9,6 +9,7 @@ dependencies = [
     "common",
     "clusterfuzz ==2.6.0",
     "pydantic ~=2.11.7",
+    "setuptools",  # Required for pkg_resources used by google-cloud-ndb (clusterfuzz dep)
 ]
 
 [project.urls]

fuzzer_runner/tests/test_fuzzer.py

@@ -0,0 +1,83 @@
+"""Tests for the fuzzer runner module."""
+
+from unittest.mock import MagicMock, patch
+
+from buttercup.fuzzer_runner.runner import Conf, Runner
+
+
+class TestRunner:
+    """Tests for the Runner class."""
+
+    @patch("buttercup.fuzzer_runner.runner.patched_temp_dir")
+    @patch("buttercup.fuzzer_runner.runner.scratch_cwd")
+    @patch("os.makedirs")
+    def test_run_fuzzer_initializes_engine(self, mock_makedirs, mock_scratch_cwd, mock_patched_temp_dir):
+        """Test run_fuzzer"""
+        from buttercup.common.types import FuzzConfiguration
+        from clusterfuzz._internal.bot.fuzzers.libFuzzer import engine as libfuzzer_engine
+
+        mock_patched_temp_dir.return_value.__enter__ = MagicMock()
+        mock_patched_temp_dir.return_value.__exit__ = MagicMock(return_value=False)
+        mock_scratch_cwd.return_value.__enter__ = MagicMock()
+        mock_scratch_cwd.return_value.__exit__ = MagicMock(return_value=False)
+
+        # Mock the engine methods that would fail without a real fuzzer binary
+        mock_opts = MagicMock()
+        mock_opts.corpus_dir = "/corpus"
+        mock_opts.arguments = []
+        mock_opts.strategies = []
+
+        mock_result = MagicMock()
+        mock_result.crashes = []
+        mock_result.logs = "test"
+        mock_result.stats = {}
+        mock_result.time_executed = 1.0
+        mock_result.timed_out = False
+
+        with (
+            patch.object(libfuzzer_engine.Engine, "prepare", return_value=mock_opts),
+            patch.object(libfuzzer_engine.Engine, "fuzz", return_value=mock_result),
+        ):
+            conf = Conf(timeout=60)
+            runner = Runner(conf)
+            fuzzconf = FuzzConfiguration(
+                corpus_dir="/corpus",
+                target_path="/target",
+                engine="libfuzzer",
+                sanitizer="address",
+            )
+
+            result = runner.run_fuzzer(fuzzconf)
+
+            assert result.crashes == []
+            assert result.timed_out is False
+
+    @patch("buttercup.fuzzer_runner.runner.scratch_dir")
+    @patch("buttercup.fuzzer_runner.runner.patched_temp_dir")
+    @patch("buttercup.fuzzer_runner.runner.scratch_cwd")
+    def test_merge_corpus_initializes_engine(self, mock_scratch_cwd, mock_patched_temp_dir, mock_scratch_dir):
+        """Test merge_corpus."""
+        from buttercup.common.types import FuzzConfiguration
+        from clusterfuzz._internal.bot.fuzzers.libFuzzer import engine as libfuzzer_engine
+
+        mock_patched_temp_dir.return_value.__enter__ = MagicMock()
+        mock_patched_temp_dir.return_value.__exit__ = MagicMock(return_value=False)
+        mock_scratch_cwd.return_value.__enter__ = MagicMock()
+        mock_scratch_cwd.return_value.__exit__ = MagicMock(return_value=False)
+
+        mock_td = MagicMock()
+        mock_td.path = "/tmp/scratch"
+        mock_scratch_dir.return_value.__enter__ = MagicMock(return_value=mock_td)
+        mock_scratch_dir.return_value.__exit__ = MagicMock(return_value=False)
+
+        with patch.object(libfuzzer_engine.Engine, "minimize_corpus"):
+            conf = Conf(timeout=60)
+            runner = Runner(conf)
+            fuzzconf = FuzzConfiguration(
+                corpus_dir="/corpus",
+                target_path="/target",
+                engine="libfuzzer",
+                sanitizer="address",
+            )
+
+            runner.merge_corpus(fuzzconf, "/output")