add repoproc for allow_auto_merge

ghconf/plumbing/repositories/common_procs.py

@@ -341,6 +341,34 @@ def _set_delete_branch_on_merge(change: Change[str]) -> Change[str]:
     return delete_branch_on_merge
 
 
+def set_allow_auto_merge(value: bool) -> repoproc_t:
+    def allow_auto_merge(org: Organization, repo: Repository, branches: Dict[str, Branch]) -> List[Change[str]]:
+        """
+        Turns on a feature that allows automatic merging of PRs
+        """
+        def _set_allow_auto_merge(change: Change[str]) -> Change[str]:
+            print_debug("[%s] Enabling auto merge" % highlight(repo.name))
+            try:
+                repo.edit(allow_auto_merge=value)
+            except GithubException:
+                return change.failure()
+
+            return change.success()
+
+        if repo.allow_auto_merge != value:
+            change = Change(
+                meta=ChangeMetadata(
+                    executor=_set_allow_auto_merge,
+                ),
+                action=ChangeActions.REPLACE,
+                before="Auto merge: %s" % "Enabled" if repo.allow_auto_merge else "Disabled",
+                after="Auto merge: %s" % "Enabled" if value else "Disabled"
+            )
+            return [change]
+        return []
+    return allow_auto_merge
+
+
 GOT = TypeVar("GOT")
 _GithubOptional = Union[GOT, _NotSetType]