Extract co-author from gitconfig (#883)

# Motivation

<!-- Why is this change necessary? -->

# Content

<!-- Please include a summary of the change -->

# Testing

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# Please check the following before marking your PR as ready for review

- [ ] I have added tests for my changes
- [ ] I have updated the documentation or added new documentation as
needed

Author: bagel897

src/codegen/git/repo_operator/repo_operator.py

@@ -471,10 +471,22 @@ def stage_and_commit_all_changes(self, message: str, verify: bool = False, exclu
                 logger.warning(f"Failed to exclude path {path}: {e}")
         return self.commit_changes(message, verify)
 
+    def _get_username_email(self) -> tuple[str, str] | None:
+        for level in ["user", "global", "system"]:
+            with self.git_cli.config_reader(level) as reader:
+                if reader.has_section("user"):
+                    user, email = reader.get_value("user", "name"), reader.get_value("user", "email")
+                    if isinstance(user, str) and isinstance(email, str) and user != CODEGEN_BOT_NAME and email != CODEGEN_BOT_EMAIL:
+                        return user, email
+        return None
+
     def commit_changes(self, message: str, verify: bool = False) -> bool:
         """Returns True if a commit was made and False otherwise."""
         staged_changes = self.git_cli.git.diff("--staged")
         if staged_changes:
+            if self.bot_commit and (info := self._get_username_email()):
+                user, email = info
+                message += f"\n\n Co-authored-by: {user} <{email}>"
             commit_args = ["-m", message]
             if self.bot_commit:
                 commit_args.append(f"--author='{CODEGEN_BOT_NAME} <{CODEGEN_BOT_EMAIL}>'")

tests/unit/codegen/sdk/python/codebase/test_codebase_git.py

@@ -1,3 +1,5 @@
+import os
+
 import pytest
 
 from codegen.sdk.codebase.factory.get_session import get_codebase_session
@@ -22,6 +24,10 @@ def test_codebase_git(tmpdir, commit: bool, sync: bool) -> None:
         codebase.get_file("dir/file0.py").insert_after("a = 1")
     c2 = codebase.git_commit("boop")
     commit = codebase.op.head_commit
+    message = commit.message
+    if not os.environ.get("CI"):
+        assert "Co-authored-by:" in message
+        assert f"Co-authored-by: {commit.author.name} <{commit.author.email}>" not in message
     codebase.sync_to_commit(commit)
     assert c1 != c2
     assert codebase.get_symbol("a", optional=True) is not None