{"id": "testing_plugins:testing-plugins-register-in-test", "page": "testing_plugins", "ref": "testing-plugins-register-in-test", "title": "Registering a plugin for the duration of a test", "content": "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: \n             from datasette import hookimpl\nfrom datasette.app import Datasette\nfrom datasette.plugins import pm\nimport pytest\n\n\n@pytest.mark.asyncio\nasync def test_using_test_plugin():\n    class TestPlugin:\n        __name__ = \"TestPlugin\"\n\n        # Use hookimpl and method names to register hooks\n        @hookimpl\n        def register_routes(self):\n            return [\n                (r\"^/error$\", lambda: 1 / 0),\n            ]\n\n    pm.register(TestPlugin(), name=\"undo\")\n    try:\n        # The test implementation goes here\n        datasette = Datasette()\n        response = await datasette.client.get(\"/error\")\n        assert response.status_code == 500\n    finally:\n        pm.unregister(name=\"undo\") \n             To reuse the same temporary plugin in multiple tests, you can register it inside a fixture in your  conftest.py  file like this: \n             from datasette import hookimpl\nfrom datasette.app import Datasette\nfrom datasette.plugins import pm\nimport pytest\nimport pytest_asyncio\n\n\n@pytest_asyncio.fixture\nasync def datasette_with_plugin():\n    class TestPlugin:\n        __name__ = \"TestPlugin\"\n\n        @hookimpl\n        def register_routes(self):\n            return [\n                (r\"^/error$\", lambda: 1 / 0),\n            ]\n\n    pm.register(TestPlugin(), name=\"undo\")\n    try:\n        yield Datasette()\n    finally:\n        pm.unregister(name=\"undo\")\n \n             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. \n             Then in a test: \n             @pytest.mark.asyncio\nasync def test_error(datasette_with_plugin):\n    response = await datasette_with_plugin.client.get(\"/error\")\n    assert response.status_code == 500", "breadcrumbs": "[\"Testing plugins\"]", "references": "[]"}