test(conflict-resolution): ✅ Add comprehensive tests for regen timeout edge cases in conflict resolution

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

tests/test_conflict_resolution.py

@@ -182,31 +182,39 @@ class TestTryAutoResolveLockfiles:
     async def test_try_auto_resolve_regen_timeout(
         self, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
     ) -> None:
+        """Regen command that times out results in regen_failed entry."""
+        import asyncio as _asyncio
+        import auto_commit_service.git.conflict_resolution as cr_mod
+        from auto_commit_service.git.conflict_resolution import LockfileStrategy
+
         repo = _make_bun_lock_conflict(tmp_path)
 
-        # Stub bun to hang (sleeping long enough to trigger timeout)
-        bin_dir = tmp_path / "stub-bin"
-        bin_dir.mkdir()
-        import os, stat as _stat
-        bun = bin_dir / "bun"
-        bun.write_text("#!/bin/sh\nsleep 999\n")
-        bun.chmod(bun.stat().st_mode | _stat.S_IEXEC | _stat.S_IXGRP | _stat.S_IXOTH)
-        monkeypatch.setenv("PATH", f"{bin_dir}:{os.environ['PATH']}")
+        short_strategy = LockfileStrategy(
+            "bun.lock", "theirs", ("bun", "install"), regen_timeout_sec=1
+        )
+        monkeypatch.setattr(cr_mod, "STRATEGY_BY_FILENAME", {"bun.lock": short_strategy})
 
-        # Patch timeout to 0 seconds so it fires immediately
-        import auto_commit_service.git.conflict_resolution as cr_mod
-        original_strategies = cr_mod.LOCKFILE_STRATEGIES
-        from auto_commit_service.git.conflict_resolution import LockfileStrategy
-        monkeypatch.setattr(
-            cr_mod,
-            "LOCKFILE_STRATEGIES",
-            (LockfileStrategy("bun.lock", "theirs", ("bun", "install"), regen_timeout_sec=1),),
-        )
-        monkeypatch.setattr(
-            cr_mod,
-            "STRATEGY_BY_FILENAME",
-            {"bun.lock": LockfileStrategy("bun.lock", "theirs", ("bun", "install"), regen_timeout_sec=1)},
-        )
+        _real_exec = _asyncio.create_subprocess_exec
+
+        class _HangingProc:
+            returncode = None
+            _killed = False
+
+            async def communicate(self, **kwargs):
+                if self._killed:
+                    return b"", b""
+                await _asyncio.sleep(9999)
+                return b"", b""
+
+            def kill(self):
+                self._killed = True
+
+        async def _fake_exec(*args, **kwargs):
+            if args[0] == "git":
+                return await _real_exec(*args, **kwargs)
+            return _HangingProc()
+
+        monkeypatch.setattr(cr_mod.asyncio, "create_subprocess_exec", _fake_exec)
 
         result = await try_auto_resolve_lockfiles(repo)
 
@@ -216,15 +224,29 @@ class TestTryAutoResolveLockfiles:
     async def test_try_auto_resolve_regen_nonzero_exit(
         self, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
     ) -> None:
+        """Regen command that exits non-zero populates regen_failed."""
+        import asyncio as _asyncio
+        import auto_commit_service.git.conflict_resolution as cr_mod
+
         repo = _make_bun_lock_conflict(tmp_path)
 
-        bin_dir = tmp_path / "stub-bin"
-        bin_dir.mkdir()
-        import os, stat as _stat
-        bun = bin_dir / "bun"
-        bun.write_text("#!/bin/sh\nexit 1\n")
-        bun.chmod(bun.stat().st_mode | _stat.S_IEXEC | _stat.S_IXGRP | _stat.S_IXOTH)
-        monkeypatch.setenv("PATH", f"{bin_dir}:{os.environ['PATH']}")
+        _real_exec = _asyncio.create_subprocess_exec
+
+        class _FailingProc:
+            returncode = 1
+
+            async def communicate(self, **kwargs):
+                return b"", b"regen error output"
+
+            def kill(self):
+                pass
+
+        async def _fake_exec(*args, **kwargs):
+            if args[0] == "git":
+                return await _real_exec(*args, **kwargs)
+            return _FailingProc()
+
+        monkeypatch.setattr(cr_mod.asyncio, "create_subprocess_exec", _fake_exec)
 
         result = await try_auto_resolve_lockfiles(repo)
 
@@ -237,13 +259,6 @@ class TestGitPullRebaseAutoResolves:
         self, tmp_path: Path, fake_bun_binary: Path
     ) -> None:
         """End-to-end: pull --rebase with a bun.lock conflict resolves automatically."""
-        repo = _make_bun_lock_conflict.__wrapped__(tmp_path) if hasattr(
-            _make_bun_lock_conflict, "__wrapped__"
-        ) else None
-
-        # Build scenario from scratch — _make_bun_lock_conflict leaves mid-rebase state,
-        # but git_pull_rebase starts by running pull --rebase itself. Set up divergence
-        # without starting rebase manually.
         bare = tmp_path / "remote.git"
         local = tmp_path / "local"