test(opencode): the 2.x schema and CLI, a fake opencode, and an opt-in real-binary contract (Issue #60)

tests/_fake_opencode.py implements the two commands MAM calls (debug paths,
session delete) as measured on 2.0.32; unit tests never run a real opencode
(it would migrate the test database). test_real_opencode_2x_contract runs a
real 2.x opencode, when installed, in a home and tmp dir of its own with
--standalone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

tests/test_issue31_purge_residual.py

@@ -34,6 +34,7 @@ sys.path.insert(0, str(SKILLS))
 from lib_py.agents.registry import get_adapter  # noqa: E402
 from lib_py.agents.base import DiscoveryContext  # noqa: E402
 from lib_py.verify_session import workspace_key  # noqa: E402
+import _fake_opencode  # noqa: E402  (tests/ is on sys.path via conftest)
 
 SESSION_ENV = ("CLAUDE_CODE_SESSION_ID", "ANTIGRAVITY_CONVERSATION_ID",
                "HERMES_SESSION_ID", "GROK_SESSION_ID", "OPENCODE_SESSION_ID")
@@ -896,9 +897,14 @@ def _db(path: Path, ddl: list, rows: list):
 
 
 def test_opencode_residual_reports_event_rows(home, tmp_path, monkeypatch):
+    # A database migrated from 1.x (Issue #60): `opencode session delete`
+    # (the fake, as measured on 2.0.32) removes the 2.x rows, the purge
+    # deletes the 1.x session/message/part rows, and todo is reported.
     u, o = f"ses_{uuidlib.uuid4().hex}", f"ses_{uuidlib.uuid4().hex}"
     db = home / ".local" / "share" / "opencode" / "opencode.db"
     ddl = ["CREATE TABLE session (id TEXT PRIMARY KEY)",
+           "CREATE TABLE session_v2 (id TEXT PRIMARY KEY, parent_id TEXT)",
+           "CREATE TABLE session_message (id TEXT, session_id TEXT)",
            "CREATE TABLE message (id TEXT, session_id TEXT)",
            "CREATE TABLE part (id TEXT, session_id TEXT)",
            "CREATE TABLE event (id TEXT, aggregate_id TEXT)",
@@ -907,6 +913,8 @@ def test_opencode_residual_reports_event_rows(home, tmp_path, monkeypatch):
     rows = []
     for s in (u, o):
         rows += [("INSERT INTO session VALUES (?)", (s,)),
+                 ("INSERT INTO session_v2 VALUES (?, NULL)", (s,)),
+                 ("INSERT INTO session_message VALUES ('sm', ?)", (s,)),
                  ("INSERT INTO message VALUES ('m', ?)", (s,)),
                  ("INSERT INTO part VALUES ('p', ?)", (s,)),
                  ("INSERT INTO event VALUES ('e1', ?)", (s,)),
@@ -915,14 +923,16 @@ def test_opencode_residual_reports_event_rows(home, tmp_path, monkeypatch):
                  ("INSERT INTO todo VALUES ('t', ?)", (s,))]
     _db(db, ddl, rows)
     adapter = get_adapter("opencode")
-    monkeypatch.setattr(adapter, "_resolve_db", lambda ctx: str(db))  # never run a real opencode
+    fake = _fake_opencode.write(tmp_path / "fakebin" / "opencode")
+    monkeypatch.setattr(adapter, "_bin", lambda ctx: fake)  # never run a real opencode
     ctx = DiscoveryContext(workspace=str(tmp_path), agent_name="opencode", home_dir=str(home))
+    assert f"{db} (session_v2.id: 1 rows)" in adapter.residual_artifacts(u, ctx)
 
-    adapter.purge_artifacts(u, ctx)
+    assert adapter.purge_artifacts(u, ctx) == [f"opencode session (with its child sessions): {u}",
+                                               f"sqlite rows for session: {u}"]
 
-    assert adapter.residual_artifacts(u, ctx) == [f"{db} (event.aggregate_id: 2 rows)",
-                                                  f"{db} (event_sequence.aggregate_id: 1 rows)",
-                                                  f"{db} (todo.session_id: 1 rows)"]
+    assert adapter.residual_artifacts(u, ctx) == [f"{db} (todo.session_id: 1 rows)"]
+    assert len(adapter.residual_artifacts(o, ctx)) == 8  # the other session is untouched: one entry per table
 
 
 def test_codex_residual_reports_name_and_thread_rows(home, tmp_path, monkeypatch, conv, other):