pytest quickstart¶

bqemulator ships a pytest plugin. After pip install bqemulator, the bqemu_server, bqemu_endpoint, and bqemu_client fixtures are available automatically — no conftest.py wiring required.

Minimal example¶

# test_orders.py
from google.cloud import bigquery

def test_create_dataset(bqemu_client):
    dataset = bqemu_client.create_dataset("sales")
    assert dataset.dataset_id == "sales"

pytest test_orders.py

Configuring the fixture¶

Override bqemu_settings to change defaults — persistent mode, logging, etc.:

# conftest.py
import pytest
from bqemulator.config import PersistenceMode, Settings

@pytest.fixture(scope="session")
def bqemu_settings(tmp_path_factory):
    return Settings(
        persistence_mode=PersistenceMode.PERSISTENT,
        data_dir=tmp_path_factory.mktemp("bqemu"),
        rest_port=0,
        grpc_port=0,
    )

With environment variables¶

The fixture exports BIGQUERY_EMULATOR_HOST automatically, so client code that reads the env var needs no special handling.

Fixture reference¶

Fixture	Scope	Returns
`bqemu_settings`	session	`Settings`
`bqemu_server`	session	running `EmulatorServer`
`bqemu_endpoint`	session	`EmulatorEndpoint(rest_url, grpc_endpoint, project_id)`
`bqemu_client`	function	`google.cloud.bigquery.Client` pointed at the emulator

Parallelism¶

pytest-xdist is supported. Each worker gets its own session-scoped emulator on a distinct free port.