parso: extend suite (#9659)

Signed-off-by: David Korczynski <david@adalogics.com>

Signed-off-by: David Korczynski <david@adalogics.com>

projects/parso/parso_diff_fuzz.py

@@ -0,0 +1,42 @@
+#!/usr/bin/python3
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import sys
+import atheris
+import parso
+
+
+def TestOneInput(data):
+  fdp = atheris.FuzzedDataProvider(data)
+
+  grammar = parso.load_grammar()
+  try:
+    module = parso.parse(fdp.ConsumeUnicodeNoSurrogates(sys.maxsize))
+    if module != None:
+      diff_parser = parso.python.diff.DiffParser(grammar._pgen_grammar,
+                                                 grammar._tokenizer, module)
+      diff_parser.update(["line1"], ["newline1"])
+  except RecursionError:
+    # Not interesting
+    pass
+
+
+def main():
+  atheris.instrument_all()
+  atheris.Setup(sys.argv, TestOneInput)
+  atheris.Fuzz()
+
+
+if __name__ == "__main__":
+  main()