tursu

Turşu

This project allows you to write Gherkin-based behavior-driven development (BDD) tests and execute them using pytest.

It compiles Gherkin syntax into Python code using Abstract Syntax Tree (AST) manipulation, enabling seamless integration with pytest for running your tests.

Enjoy practicing BDD in modern Python (3.10+), type hinting, asyncio, dataclasses or Pydantic, pytest, playwright.

Features

• Write tests using Gherkin syntax.
• Write step definitions in Python for with type hinting to cast Gherkin parameters.
• Execute tests directly with pytest.
• Compile Gherkin scenarios to Python code using AST.

Getting started

Installation using uv

uv add --group dev tursu

Creating a new test suite

The simplest way to initialize a test suite is to run the Turşu cli.

uv run tursu init

Discover your tests.

𝝿 uv run pytest --collect-only tests/functionals
========================== test session starts ==========================
platform linux -- Python 3.13.2, pytest-8.3.5, pluggy-1.5.0
configfile: pyproject.toml
plugins: cov-6.0.0
collected 3 items

<Dir tursu>
  <Package tests>
    <Package funcs>
      <GherkinDocument login.feature>
        <Function test_7_Successful_sign_in_with_valid_credentials>
        <Function test_10_Sign_in_fails_with_wrong_password>
        <Function test_17_User_can_t_login_with_someone_else_username_16[Examples_16_0]>
        <Function test_17_User_can_t_login_with_someone_else_username_16[Examples_16_1]>

====================== 3 tests collected in 0.01s =======================

Run the tests.

All the suite

𝝿 uv run pytest tests/functionals
========================== test session starts ==========================
platform linux -- Python 3.13.2, pytest-8.3.5, pluggy-1.5.0
configfile: pyproject.toml
collected 3 items

tests/functionals/test_login.py ...                               [ 33%]
..                                                                [100%]

=========================== 3 passed in 0.02s ===========================

All the suite with details:

𝝿 uv run pytest -v tests/functionals
============================= test session starts =============================
platform linux -- Python 3.13.2, pytest-8.3.5, pluggy-1.5.0
configfile: pyproject.toml
collected 3 items

📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario: Successful sign-in with valid credentials
✅ Given a set of users:
✅ When Bob signs in with password dumbsecret
✅ Then the user is connected with username Bob

📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario: Sign-in fails with wrong password
✅ Given a set of users:
✅ When Bob signs in with password notthat
✅ Then the user is not connected

📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario Outline: User can\'t login with someone else username
✅ Given a set of users:
✅ When Bob signs in with password anothersecret
✅ Then the user is not connected

📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario Outline: User can\'t login with someone else username
✅ Given a set of users:
✅ When Alice signs in with password dumbsecret
✅ Then the user is not connected
                                                                         PASSED

============================== 3 passed in 0.02s ==============================

Choose your scenario file to test:

𝝿 uv run pytest -vv tests/functionals/login.feature
========================== test session starts ==========================
platform linux -- Python 3.13.2, pytest-8.3.5, pluggy-1.5.0
configfile: pyproject.toml
plugins: cov-6.0.0, tursu-0.11.1
collected 3 items

tests/functionals/login.feature::test_3_User_can_login <- test_login.py
📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario: Successful sign-in with valid credentials
⏳ Given a user Bob with password dumbsecret
✅ Given a user Bob with password dumbsecret
⏳ When Bob signs in with password dumbsecret
✅ When Bob signs in with password dumbsecret
⏳ Then the user is connected with username Bob
✅ Then the user is connected with username Bob
                                                            PASSED [ 33%]
tests/functionals/login.feature::test_7_User_can_t_login_with_wrong_password <- test_login.py
📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario: Sign-in fails with wrong password
⏳ Given a user Bob with password dumbsecret
✅ Given a user Bob with password dumbsecret
⏳ When Bob signs in with password notthat
✅ When Bob signs in with password notthat
⏳ Then the user is not connected
✅ Then the user is not connected
                                                            PASSED [ 66%]
tests/functionals/login.feature::test_12_User_can_t_login_with_someone_else_username <- test_login.py
📄 Document: login.feature
🥒 Feature: User signs in with the right password
🎬 Scenario: User can\'t login with someone else username
⏳ Given a user Bob with password bobsecret
✅ Given a user Bob with password bobsecret
⏳ Given a user Alice with password alicesecret
✅ Given a user Alice with password alicesecret
⏳ When Alice signs in with password bobsecret
✅ When Alice signs in with password bobsecret
⏳ Then the user is not connected
✅ Then the user is not connected

                                                            PASSED [100%]
=========================== 3 passed in 0.02s ===========================

You can choose the test name ( tests/tests2/login.feature::test_3_User_can_login )
or even decorate with tag and use pytest markers (`pytest -m <tag>`).

Get errors context

𝝿 uv run pytest tests/functionals
========================== test session starts ===========================
platform linux -- Python 3.13.2, pytest-8.3.5, pluggy-1.5.0
rootdir: /home/guillaume/workspace/git/tursu
configfile: pyproject.toml
plugins: cov-6.0.0, tursu-0.12.4, playwright-0.7.0, base-url-2.1.0
collected 3 items

tests/functionals/login.feature F..                                      [100%]

================================ FAILURES ================================
_________________________ test_3_User_can_login __________________________

self = <tursu.runner.TursuRunner object at 0x76103daadbe0>, step = 'Then'
text = 'the user is connected with username Bobby'
kwargs = {'app': <tests.functionals.conftest.DummyApp object at 0x76103daad940>}

    def run_step(
        self,
        step: StepKeyword,
        text: str,
        **kwargs: Any,
    ) -> None:
        try:
>           self.tursu.run_step(self, step, text, **kwargs)

src/tursu/runner.py:79:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
src/tursu/registry.py:102: in run_step
    handler(**matches)
src/tursu/steps.py:38: in __call__
    self.hook(**kwargs)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

app = <tests.functionals.conftest.DummyApp object at 0x76103daad940>
username = 'Bobby'

    @then("the user is connected with username {username}")
    def assert_connected(app: DummyApp, username: str):
>       assert app.connected_user == username
E       AssertionError

tests/functionals/steps.py:18: AssertionError

The above exception was the direct cause of the following exception:

request = <FixtureRequest for <Function test_3_User_can_login>>
capsys = <_pytest.capture.CaptureFixture object at 0x76103daae270>
tursu = <tursu.runtime.registry.Tursu object at 0x76103f107230>
app = <tests.functionals.conftest.DummyApp object at 0x76103daad940>

>   ???

test_login.py:12:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tursu.runner.TursuRunner object at 0x76103daadbe0>, step = 'Then'
text = 'the user is connected with username Bobby'
kwargs = {'app': <tests.functionals.conftest.DummyApp object at 0x76103daad940>}

    def run_step(
        self,
        step: StepKeyword,
        text: str,
        **kwargs: Any,
    ) -> None:
        try:
            self.tursu.run_step(self, step, text, **kwargs)
        except Exception as exc:
>           raise ScenarioFailed(self.fancy()) from exc
E           tursu.runtime.runner.ScenarioFailed:
E           ┌────────────────────────────────────────────────────────┐
E           │ 📄 Document: login.feature                             │
E           │ 🥒 Feature: User signs in with the right password      │
E           │ 🎬 Scenario: Successful sign-in with valid credentials │
E           │ ✅ Given a set of users:                               │
E           │ ✅ When Bob signs in with password dumbsecret          │
E           │ ❌ Then the user is connected with username Bobby      │
E           └────────────────────────────────────────────────────────┘

src/tursu/runner.py:81: ScenarioFailed
======================== short test summary info =========================
FAILED tests/functionals/login.feature::test_3_User_can_login - tursu.runner.ScenarioFailed:

If --trace is used, or -vvv, the tests files are written on the disk, and
the `???` in the context are replaced by the generated python test function.

This may be usefull in case of hard time debugging.

Great support of playwright.

Combining Turşu and pytest-playwright is a great experience. See the example in the documentation

Great support of asyncio.

Turşu can also be combined with pytest-playwright-asyncio and run tests has coroutine using pytest-asyncio.

Scenario can be decorated with a @asyncio tag. And they will run as a coroutine marked with @pytest.mark.asyncio.

And, the step definitions can be coroutine.

See the pytest-playwright-asyncio example in the documentation

Great support of pytest fixtures and faker.

See the example in the documentation

All Gherkin features are support.

Turşu use the gherkin-official package to parse Gherkin Scenario beeing compiled to python.

• ✅ Feature (converted to python module)
• ✅ Scenario (converted to debuggable python test function or coroutine)
• ✅ Scenario Outlines / Examples (converted to @pytest.mark.parametrize test function or coroutine)
• ✅ Background (Step copied to all the functions of the scenario)
• ✅ Rule (tags converted to pytest marker)
• ✅ Steps (Given, When, Then, And, But, bound to the step definition provided.)
• ✅ Tags (converted to pytest marker on Feature, Scenario, Scenario Outline and Rule)
• ✅ Doc String (support casting of json to python model with the lib of your choice: pydantic, dataclasses,...)
• ✅ Data Table (support casting to python model with the lib of your choice)