Build reusable bot framework

tests/unit/test_migration_engine.py

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+"""Unit tests for migration discovery and history decisions."""
+
+from contextlib import contextmanager
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+import pytest
+
+from core import migrations
+
+
+@pytest.fixture
+def migrationRoot():
+    with TemporaryDirectory(prefix=".migration-test-", dir=Path.cwd()) as directory:
+        yield Path(directory)
+
+
+def _writeMigration(root, relativePath, content="SELECT 1;"):
+    path = root / relativePath
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(content, encoding="utf-8")
+    return path
+
+
+class FakeCursor:
+    def __init__(self, applied=None, historyTable=True):
+        self.applied = list(applied or [])
+        self.historyTable = historyTable
+        self.executed = []
+        self._one = None
+        self._all = []
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_args):
+        return False
+
+    def execute(self, query, params=None):
+        normalized = " ".join(query.split())
+        self.executed.append((normalized, params))
+        if "SELECT to_regclass" in normalized:
+            self._one = {
+                "table_name": "schema_migrations" if self.historyTable else None
+            }
+        elif normalized.startswith("SELECT namespace, version, checksum"):
+            self._all = self.applied
+
+    def fetchone(self):
+        return self._one
+
+    def fetchall(self):
+        return self._all
+
+
+class FakeConnection:
+    def __init__(self, cursor):
+        self.activeCursor = cursor
+
+    def cursor(self, **_kwargs):
+        return self.activeCursor
+
+
+def _connectionFor(cursor):
+    @contextmanager
+    def fakeConnection():
+        yield FakeConnection(cursor)
+
+    return fakeConnection
+
+
+def test_discovery_orders_core_before_feature_namespaces(migrationRoot):
+    _writeMigration(migrationRoot, "config/migrations/0002_second.sql", "SELECT 2;")
+    _writeMigration(migrationRoot, "config/migrations/0001_first.sql", "SELECT 1;")
+    _writeMigration(migrationRoot, "modules/zeta/migrations/0001_zeta.sql")
+    _writeMigration(migrationRoot, "modules/alpha/migrations/0002_alpha.sql")
+
+    found = migrations.discover_migrations(migrationRoot)
+
+    assert [(item.namespace, item.version) for item in found] == [
+        ("core", 1),
+        ("core", 2),
+        ("alpha", 2),
+        ("zeta", 1),
+    ]
+    assert len(found[0].checksum) == 64
+    assert found[0].path == Path(
+        migrationRoot, "config/migrations/0001_first.sql"
+    )
+
+
+def test_discovery_rejects_bad_names_and_duplicate_versions(migrationRoot):
+    _writeMigration(migrationRoot, "config/migrations/not-numbered.sql")
+    with pytest.raises(migrations.MigrationError, match="Invalid migration filename"):
+        migrations.discover_migrations(migrationRoot)
+
+    Path(migrationRoot, "config/migrations/not-numbered.sql").unlink()
+    _writeMigration(migrationRoot, "config/migrations/0001_first.sql")
+    _writeMigration(migrationRoot, "config/migrations/0001_duplicate.sql")
+    with pytest.raises(migrations.MigrationError, match="Duplicate migration"):
+        migrations.discover_migrations(migrationRoot)
+
+
+def test_upgrade_applies_pending_and_skips_matching_history(
+    migrationRoot, monkeypatch
+):
+    _writeMigration(migrationRoot, "config/migrations/0001_first.sql", "SELECT 42;")
+    migration = migrations.discover_migrations(migrationRoot)[0]
+    cursor = FakeCursor()
+    monkeypatch.setattr(migrations.postgres, "get_connection", _connectionFor(cursor))
+
+    assert migrations.upgrade(migrationRoot) == [migration]
+    queries = [query for query, _params in cursor.executed]
+    assert any("pg_advisory_xact_lock" in query for query in queries)
+    assert "SELECT 42;" in queries
+    assert any(query.startswith("INSERT INTO schema_migrations") for query in queries)
+
+    cursor = FakeCursor(
+        applied=[
+            {
+                "namespace": "core",
+                "version": 1,
+                "checksum": migration.checksum,
+                "applied_at": None,
+            }
+        ]
+    )
+    monkeypatch.setattr(migrations.postgres, "get_connection", _connectionFor(cursor))
+    assert migrations.upgrade(migrationRoot) == []
+    assert "SELECT 42;" not in [query for query, _params in cursor.executed]
+
+
+def test_upgrade_rejects_changed_applied_migration(migrationRoot, monkeypatch):
+    _writeMigration(migrationRoot, "config/migrations/0001_first.sql", "SELECT 1;")
+    cursor = FakeCursor(
+        applied=[
+            {
+                "namespace": "core",
+                "version": 1,
+                "checksum": "0" * 64,
+                "applied_at": None,
+            }
+        ]
+    )
+    monkeypatch.setattr(migrations.postgres, "get_connection", _connectionFor(cursor))
+
+    with pytest.raises(migrations.MigrationError, match="checksum changed"):
+        migrations.upgrade(migrationRoot)
+
+
+def test_status_handles_new_database_and_missing_source(migrationRoot, monkeypatch):
+    _writeMigration(migrationRoot, "config/migrations/0001_first.sql", "SELECT 1;")
+    cursor = FakeCursor(historyTable=False)
+    monkeypatch.setattr(migrations.postgres, "get_connection", _connectionFor(cursor))
+    assert migrations.migration_status(migrationRoot)[0]["state"] == "pending"
+
+    cursor = FakeCursor(
+        applied=[
+            {
+                "namespace": "removed_feature",
+                "version": 3,
+                "checksum": "a" * 64,
+                "applied_at": "earlier",
+            }
+        ]
+    )
+    monkeypatch.setattr(migrations.postgres, "get_connection", _connectionFor(cursor))
+    status = migrations.migration_status(migrationRoot)
+    assert [item["state"] for item in status] == ["pending", "missing"]
+    assert status[1]["namespace"] == "removed_feature"