id,page,ref,title,content,breadcrumbs,references
testing_plugins:testing-plugins-datasette-test-instance,testing_plugins,testing-plugins-datasette-test-instance,Setting up a Datasette test instance,"The above example shows the easiest way to start writing tests against a Datasette instance: 
             from datasette.app import Datasette
import pytest


@pytest.mark.asyncio
async def test_plugin_is_installed():
    datasette = Datasette(memory=True)
    response = await datasette.client.get(""/-/plugins.json"")
    assert response.status_code == 200 
             Creating a  Datasette()  instance like this as useful shortcut in tests, but there is one detail you need to be aware of. It's important to ensure that the async method  .invoke_startup()  is called on that instance. You can do that like this: 
             datasette = Datasette(memory=True)
await datasette.invoke_startup() 
             This method registers any  startup(datasette)  or  prepare_jinja2_environment(env, datasette)  plugins that might themselves need to make async calls. 
             If you are using  await datasette.client.get()  and similar methods then you don't need to worry about this - Datasette automatically calls  invoke_startup()  the first time it handles a request.","[""Testing plugins""]",[]
testing_plugins:testing-plugins-pdb,testing_plugins,testing-plugins-pdb,Using pdb for errors thrown inside Datasette,"If an exception occurs within Datasette itself during a test, the response returned to your plugin will have a  response.status_code  value of 500. 
             You can add  pdb=True  to the  Datasette  constructor to drop into a Python debugger session inside your test run instead of getting back a 500 response code. This is equivalent to running the  datasette  command-line tool with the  --pdb  option. 
             Here's what that looks like in a test function: 
             def test_that_opens_the_debugger_or_errors():
    ds = Datasette([db_path], pdb=True)
    response = await ds.client.get(""/"") 
             If you use this pattern you will need to run  pytest  with the  -s  option to avoid capturing stdin/stdout in order to interact with the debugger prompt.","[""Testing plugins""]",[]
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"")","[""Testing plugins""]",[]