spltz-viur-light-mock 0.1.0

Pytest helpers and viur-core stand-ins for testing ViUR packages without App Engine.

viur-light-mock

Pytest helpers and viur.core.* stand-ins for testing ViUR packages without App Engine.

What it does

viur-light-mock is a pytest plugin that injects lightweight stand-ins for the viur.core.* modules into sys.modules before your tests are collected. That lets a package import from viur.core import db, utils, errors, … in production code while the tests run hermetically — no Google App Engine stack, no Datastore connection, fast cold-start.

The plugin auto-discovers via the pytest11 entry-point. No conftest.py boilerplate, no pytest_plugins = line — install the package and the fixtures and mocks are there.

Requirements

• Python ≥ 3.12
• pytest ≥ 8

Install

The PyPI distribution name is spltz-viur-light-mock (the experimental spltz- prefix marks it pre-1.0). The Python import path stays viur.light_mock — namespace package, no rename in user code.

pip install spltz-viur-light-mock

For a ViUR-based package that wants to use it:

[project.optional-dependencies]
test = ["pytest", "pytest-cov", "spltz-viur-light-mock>=0.1"]

Usage

Just write tests as if viur.core were real:

# tests/test_my_module.py
def test_something(db_state, freeze_time, make_query):
    from viur.core.db import Entity, Key
    from my_package import MyAdapter

    existing = Entity(Key("order_revision", 1))
    existing["revision_index"] = 7
    make_query(single=existing)

    MyAdapter().do_something()

    assert any(p["revision_index"] == 8 for p in db_state.put_calls)

The fixtures used here (db_state, freeze_time, make_query) are auto-discovered from the plugin — you don't need to import them or wire them up in a conftest.py.

What's mocked

Module	Stand-in surface
viur.core	Plus identity decorators exposed, force_post, skey
viur.core.db	Key, Entity, Query, SortOrder, Get, Put, Delete, AllocateIDs
viur.core.utils	utcNow() — freezable
viur.core.errors	Unauthorized, Forbidden, BadRequest, NotFound
viur.core.current	user, request slots with .get/.set
viur.core.skeleton	Skeleton, SkeletonInstance, DatabaseAdapter
viur.core.tasks	PeriodicTask decorator (no-op, but tags the wrapped function)
viur.core.render.json.default	CustomJsonEncoder aliased to stdlib json.JSONEncoder

Fixtures

Fixture	Purpose
db_state	Handle on the in-memory datastore (store, put_calls, delete_calls, …)
freeze_time	Pin utils.utcNow() to a controllable value
make_query	Pre-populate the next db.Query(...) with single/many results
patched_user	Set current.user.get() to a fake user dict
_viur_light_mock_reset_state	Autouse — resets the fake datastore singleton between tests

Public API

If you need to drive the mocks from your own conftest.py (for example to add a project-specific stand-in), import directly:

from viur.light_mock import (
    install_viur_core_mocks,
    FakeKey, FakeEntity, FakeQuery, FakeSortOrder, DbState,
)

Why not just use unittest.mock?

You can — but the fake viur.core modules here are real Python modules in sys.modules, so from viur.core import db resolves naturally without patching every test, and isinstance checks against db.Entity etc. work out of the box.

Development

git clone https://github.com/sprengplatz/viur-light-mock
cd viur-light-mock
pip install -e ".[dev]"
pytest                  # 100% coverage required

License

MIT — see LICENSE.