Testing

Flaskteroids provides a Rails-style testing layer powered by pytest. Installing flaskteroids includes pytest, pytest-xdist for parallel testing, and Playwright for system testing; no extra or development dependencies are needed. New applications include a test/ directory, test configuration, and a GitHub Actions workflow.

Run model, controller, job, and mailer tests with:

flask test

Run browser tests separately, as in Rails:

flask test:system

Arguments are passed to pytest:

flask test -n auto
flask test test/controllers/posts_controller_test.py

The command selects the test environment and applies pending migrations to the test database before collection. Tests that inherit from a Flaskteroids test class run in a transaction that is rolled back after every test.

Test types

from test.test_helper import (
    IntegrationTest,
    JobTest,
    MailerTest,
    ModelTest,
    SystemTest,
)

Generated tests use files ending in _test.py and classes ending in Test.

Fixtures

Fixtures live under test/fixtures:

# test/fixtures/posts.yml
one:
  title: First post
  content: First post content

two:
  title: Second post
  content: Second post content

Declare and access them from a test:

class PostTest(ModelTest):
    fixtures = ["posts"]

    def setup(self):
        self.post = self.posts("one")

Fixtures are loaded inside the test transaction.

Integration tests

from test.test_helper import IntegrationTest, get, post
from app.models.post import Post
from flaskteroids.routes import post_url, posts_url


class PostsControllerTest(IntegrationTest):
    fixtures = ["posts"]

    def test_should_get_index(self):
        get(posts_url())
        self.assert_response("success")

    def test_should_create_post(self):
        with self.assert_difference(Post.count):
            post(
                posts_url(),
                params={"post": {"title": "New post", "content": "Content"}},
            )

        self.assert_redirected_to(post_url(Post.last()))

Available request functions are get, post, patch, put, and delete.

Jobs and mail

The test environment uses in-memory job and mail adapters:

with self.assert_enqueued_with(job=PublishPostJob, args=[post]):
    PublishPostJob.perform_later(post)

with self.perform_enqueued_jobs():
    PublishPostJob.perform_later(post)

with self.assert_emails(1):
    PostsMailer.published(post).deliver_now()

No broker or SMTP server is required.

System tests

System tests use Playwright while exposing a Rails-like browser API:

class PostsTest(SystemTest):
    def test_visiting_posts(self):
        self.visit(posts_path())
        self.assert_selector("h1", text="Posts")

The Playwright Python package is included with Flaskteroids. Its browser binaries are installed separately; install Chromium locally before running system tests for the first time:

playwright install chromium