Testing Migrations

runic ships two distinct testing mechanisms:

• runic test CLI command — round-trip tests a single revision against a real graph.
• runic.migrate.testing pytest fixtures — utilities for writing unit and integration tests for migration scripts in your own test suite.

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Round-trip testing with runic test

runic test <rev> runs a three-phase idempotency check on an ephemeral graph:

• Phase A — upgrade to the target revision.
• Phase B — downgrade to base.
• Phase C — upgrade again (idempotency check).

At each phase, runic reports the count of nodes, indexes, and constraints:

$ runic test 3f9a12c1
runic test 3f9a12c1ab4e
─────────────────────────────────────────────
Phase A (upgrade):    ✓  nodes=0  indices=1  constraints=1
Phase B (downgrade):  ✓  nodes=0  indices=0  constraints=0
Phase C (idempotency):✓  nodes=0  indices=1  constraints=1
─────────────────────────────────────────────
PASSED

The command creates a temporary graph named <source_graph>__test_<rev>_<token>, runs all three phases, then deletes the graph — regardless of pass or fail. Your production graph is never touched.

Running against an embedded server

You can point runic test at a separate URL to avoid needing a production connection:

$ runic test 3f9a12c1 --url falkor://localhost:6379 --graph test_graph

Or use falkordblite for an embedded server (no Docker required). Configure env.py to use the embedded adapter:

# runic/env.py  (falkordblite variant)
from pathlib import Path
from redislite import FalkorDB
from runic.migrate import context
from runic.migrate.adapters.falkordb import FalkorDBAdapter

db = FalkorDB(protocol=2)
graph = db.select_graph("test")
adapter = FalkorDBAdapter(db, graph)
context.configure(adapter, script_location=Path("runic"))

Then run runic test 3f9a12c1 without any --url flag.

pytest fixtures

runic.migrate.testing exports two pytest fixtures for use in your own test suite. Add to your conftest.py:

from runic.migrate.testing import falkordb_graph, runic_context  # noqa: F401

Or import directly in test files:

import pytest
from runic.migrate.testing import falkordb_graph, runic_context

The fixtures use falkordblite (installed as redislite) for an embedded FalkorDB server that starts and stops with the test process.

INFO

Both fixtures skip the test automatically if falkordblite is not installed. Install it with uv add --dev falkordblite.

falkordb_graph fixture

Yields a (db, graph) tuple backed by an ephemeral embedded graph. The graph is deleted after the test.

def test_index_creation(falkordb_graph) -> None:
    db, graph = falkordb_graph
    graph.query("CREATE INDEX FOR (n:User) ON (n.id)")
    result = graph.ro_query("CALL db.indexes() YIELD label")
    assert result.result_set

runic_context fixture

Yields a fully configured Runic instance backed by an ephemeral embedded graph and a temporary versions/ directory. Use this to test upgrade/downgrade logic end-to-end.

from pathlib import Path
from runic.migrate.context import Runic
from runic.migrate.testing import runic_context

def test_full_migration(runic_context, tmp_path) -> None:
    ctx = runic_context
    versions = ctx.script_location / "versions"

    # Write a migration script programmatically
    (versions / "0001_test_index.py").write_text("""
from datetime import UTC, datetime
revision = "0001"
down_revision = None
branch_labels = []
depends_on = []
irreversible = False
snapshot = False
message = "test"
create_date = datetime.now(UTC)

def upgrade(op) -> None:
    op.create_range_index("Person", "email")

def downgrade(op) -> None:
    op.drop_range_index("Person", "email")
""")

    # Create a fresh Runic instance to pick up the new revision file
    ctx2 = Runic(ctx.adapter, ctx.script_location)

    ctx2.upgrade("head")
    assert ctx2.current() == "0001"

    ctx2.downgrade("base")
    assert ctx2.current() is None

Writing testable migration scripts

Keep migration scripts testable by avoiding side effects outside upgrade and downgrade:

• Do not query the database at module import time.
• Keep all state in op.* calls or local variables.
• For seed data, prefer deterministic op.seed(...) calls over op.run_cypher with hard-coded values.

Use the runic test command as a first-pass sanity check before committing, and write focused pytest tests for scripts that involve complex data transformations.

Integration test markers

If you add the integration pytest marker to tests that require falkordblite, you can skip them in environments without it:

@pytest.mark.integration
def test_migration_round_trip(runic_context) -> None:
    ...

# Run only unit tests (skip integration)
pytest -m "not integration"

# Run all including integration
pytest