id,page,ref,title,content,breadcrumbs,references
testing_plugins:testing-plugins-register-in-test,testing_plugins,testing-plugins-register-in-test,Registering a plugin for the duration of a test,"When writing tests for plugins you may find it useful to register a test plugin just for the duration of a single test. You can do this using  pm.register()  and  pm.unregister()  like this: 
             from datasette import hookimpl
from datasette.app import Datasette
from datasette.plugins import pm
import pytest


@pytest.mark.asyncio
async def test_using_test_plugin():
    class TestPlugin:
        __name__ = ""TestPlugin""

        # Use hookimpl and method names to register hooks
        @hookimpl
        def register_routes(self):
            return [
                (r""^/error$"", lambda: 1 / 0),
            ]

    pm.register(TestPlugin(), name=""undo"")
    try:
        # The test implementation goes here
        datasette = Datasette()
        response = await datasette.client.get(""/error"")
        assert response.status_code == 500
    finally:
        pm.unregister(name=""undo"") 
             To reuse the same temporary plugin in multiple tests, you can register it inside a fixture in your  conftest.py  file like this: 
             from datasette import hookimpl
from datasette.app import Datasette
from datasette.plugins import pm
import pytest
import pytest_asyncio


@pytest_asyncio.fixture
async def datasette_with_plugin():
    class TestPlugin:
        __name__ = ""TestPlugin""

        @hookimpl
        def register_routes(self):
            return [
                (r""^/error$"", lambda: 1 / 0),
            ]

    pm.register(TestPlugin(), name=""undo"")
    try:
        yield Datasette()
    finally:
        pm.unregister(name=""undo"")
 
             Note the  yield  statement here - this ensures that the  finally:  block that unregisters the plugin is executed only after the test function itself has completed. 
             Then in a test: 
             @pytest.mark.asyncio
async def test_error(datasette_with_plugin):
    response = await datasette_with_plugin.client.get(""/error"")
    assert response.status_code == 500","[""Testing plugins""]",[]