id,page,ref,title,content,breadcrumbs,references
testing_plugins:testing-plugins-fixtures,testing_plugins,testing-plugins-fixtures,Using pytest fixtures,"Pytest fixtures  can be used to create initial testable objects which can then be used by multiple tests. 
             A common pattern for Datasette plugins is to create a fixture which sets up a temporary test database and wraps it in a Datasette instance. 
             Here's an example that uses the  sqlite-utils library  to populate a temporary test database. It also sets the title of that table using a simulated  metadata.json  configuration: 
             from datasette.app import Datasette
import pytest
import sqlite_utils


@pytest.fixture(scope=""session"")
def datasette(tmp_path_factory):
    db_directory = tmp_path_factory.mktemp(""dbs"")
    db_path = db_directory / ""test.db""
    db = sqlite_utils.Database(db_path)
    db[""dogs""].insert_all(
        [
            {""id"": 1, ""name"": ""Cleo"", ""age"": 5},
            {""id"": 2, ""name"": ""Pancakes"", ""age"": 4},
        ],
        pk=""id"",
    )
    datasette = Datasette(
        [db_path],
        metadata={
            ""databases"": {
                ""test"": {
                    ""tables"": {
                        ""dogs"": {""title"": ""Some dogs""}
                    }
                }
            }
        },
    )
    return datasette


@pytest.mark.asyncio
async def test_example_table_json(datasette):
    response = await datasette.client.get(
        ""/test/dogs.json?_shape=array""
    )
    assert response.status_code == 200
    assert response.json() == [
        {""id"": 1, ""name"": ""Cleo"", ""age"": 5},
        {""id"": 2, ""name"": ""Pancakes"", ""age"": 4},
    ]


@pytest.mark.asyncio
async def test_example_table_html(datasette):
    response = await datasette.client.get(""/test/dogs"")
    assert "">Some dogs</h1>"" in response.text 
             Here the  datasette()  function defines the fixture, which is than automatically passed to the two test functions based on pytest automatically matching their  datasette  function parameters. 
             The  @pytest.fixture(scope=""session"")  line here ensures the fixture is reused for the full  pytest  execution session. This means that the temporary database file will be created once and reused for each test. 
             If you want to create that test database repeatedly for every individual test function, write the fixture function like this instead. You may want to do this if your plugin modifies the database contents in some way: 
             @pytest.fixture
def datasette(tmp_path_factory):
    # This fixture will be executed repeatedly for every test
    ...","[""Testing plugins""]","[{""href"": ""https://docs.pytest.org/en/stable/fixture.html"", ""label"": ""Pytest fixtures""}, {""href"": ""https://sqlite-utils.datasette.io/en/stable/python-api.html"", ""label"": ""sqlite-utils library""}]"