SERVER-51335 Persist fuzzer corpora for each branch and variant

buildscripts/resmokelib/testing/hooks/cpp_libfuzzer.py

@@ -0,0 +1,57 @@
+"""Test hook that does maintainence tasks for libfuzzer tests."""
+
+import os
+
+from buildscripts.resmokelib import core
+from buildscripts.resmokelib import errors
+from buildscripts.resmokelib import utils
+from buildscripts.resmokelib.testing.fixtures import interface as fixture_interface
+from buildscripts.resmokelib.testing.hooks import interface
+
+
+class LibfuzzerHook(interface.Hook):  # pylint: disable=too-many-instance-attributes
+    """Merges inputs after a fuzzer run."""
+
+    DESCRIPTION = ("Merges inputs after a fuzzer run")
+
+    def __init__(self, hook_logger, fixture):
+        """Initialize the ContinuousStepdown.
+
+        Args:
+            hook_logger: the logger instance for this hook.
+            fixture: the target fixture.
+        """
+        interface.Hook.__init__(self, hook_logger, fixture, LibfuzzerHook.DESCRIPTION)
+
+        self._fixture = fixture
+
+    def before_suite(self, test_report):
+        """Before suite."""
+        pass
+
+    def after_suite(self, test_report):
+        """After suite."""
+        pass
+
+    def before_test(self, test, test_report):
+        """Before test."""
+        pass
+
+    def after_test(self, test, test_report):
+        """After test."""
+        self._merge_corpus(test)
+
+    def _merge_corpus(self, test):
+        self.logger.info(f"Merge for {test.short_name()} libfuzzer test started, "
+                         f"merging to {test.merged_corpus_directory}.")
+        os.makedirs(test.merged_corpus_directory, exist_ok=True)
+        default_args = [
+            test.program_executable,
+            "-merge=1",
+            test.merged_corpus_directory,
+            test.corpus_directory,
+        ]
+        process = core.programs.make_process(self.logger, default_args, **test.program_options)
+        process.start()
+        process.wait()
+        self.logger.info(f"Merge for {test.short_name()} libfuzzer test finished.")