feat: add support for proto maps with enum values

[simonresch]

Adds mutator support for protobuf maps where the map value is a protobuf enum.

message TestProtobuf {
  enum Enum {
    Label1 = 0;
    Label2 = 1;
    Label3 = 2;
    Label4 = 3;
    Label5 = 4;
  }

  map<int32, Enum> map_field = 1;
}

[Copilot]

Pull Request Overview

This PR adds support for protobuf maps where the value type is a protobuf enum. Previously, the code only handled map values that were messages, but now it recursively processes map value fields to support both enum and message types.

Key changes:

• Refactored map field handling to recursively process the value field descriptor
• Added test coverage for enum-valued maps in both proto2 and proto3
• Updated expected test outputs to include the new enum map mutator representations

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/main/java/com/code_intelligence/jazzer/mutation/mutator/proto/BuilderMutatorFactory.java	Refactored map field handling to recursively process value fields, supporting both enum and message map values
src/test/java/com/code_intelligence/jazzer/mutation/mutator/proto/proto3.proto	Added EnumMapField3 test message with enum-valued map
src/test/java/com/code_intelligence/jazzer/mutation/mutator/proto/proto2.proto	Added enum_map and message_map fields to TestProtobuf
src/test/java/com/code_intelligence/jazzer/mutation/mutator/StressTest.java	Added test case for EnumMapField3 and updated expected mutator representations

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[oetr]

LGTM! Nice use of recursion!
You can set the timeout="long" for the failing test. It is very sensitive to PRNG-related changes. In this case you added new fields to proto2 and changed the mutations that are always running with the same seed. You can also find a better seed, if you have time!