Autouse fixtures in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to make the fixture run automatically for each test.

PyTest

import pytest

@pytest.fixture([1])
def setup_data():
    print("Setup data")


def test_example():
    assert True

Drag options to blanks, or click blank then click option'

Ascope='module'

Bautouse=True

Cparams=[1,2]

Dname='setup'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'scope' instead of 'autouse' to run fixture automatically.

Forgetting to set autouse=True so fixture does not run automatically.

The 'autouse=True' parameter makes the fixture run automatically for each test without needing to be explicitly used.

2fill in blank

medium

Complete the code to verify that the autouse fixture runs before the test function.

PyTest

import pytest

@pytest.fixture([1])
def setup_env():
    print("Environment setup")


def test_run():
    assert True

Drag options to blanks, or click blank then click option'

Aautouse=True

Bscope='session'

Cparams=[1]

Dname='env'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'scope' without autouse does not run fixture automatically.

Not adding any parameter so fixture is not triggered.

Setting autouse=True ensures the fixture runs automatically before the test function.

3fill in blank

hard

Fix the error in the fixture declaration to make it autouse.

PyTest

import pytest

@pytest.fixture(autouse=[1])
def prepare():
    print("Preparing")


def test_check():
    assert True

Drag options to blanks, or click blank then click option'

A"True"

B1

CTrue

DFalse

Attempts:

3 left

💡 Hint

Common Mistakes

Passing 'True' as a string instead of boolean True.

Using 1 instead of True which may cause confusion.

The autouse parameter must be a boolean True without quotes to work correctly.

4fill in blank

hard

Fill both blanks to create an autouse fixture with module scope.

PyTest

import pytest

@pytest.fixture([1], [2])
def setup_module():
    print("Module setup")


def test_one():
    assert True

Drag options to blanks, or click blank then click option'

Aautouse=True

Bscope='function'

Cscope='module'

Dautouse=False

Attempts:

3 left

💡 Hint

Common Mistakes

Using scope='function' which runs fixture for each test function.

Setting autouse=False so fixture does not run automatically.

To make a fixture run automatically for all tests in a module, use autouse=True and scope='module'.

5fill in blank

hard

Fill all three blanks to create an autouse fixture with function scope and a print statement.

PyTest

import pytest

@pytest.fixture([1], [2])
def setup_func():
    print([3])


def test_sample():
    assert True

Drag options to blanks, or click blank then click option'

Aautouse=True

Bscope='function'

C"Function setup running"

D"Setup running"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong scope like 'module' when function scope is needed.

Not using autouse=True so fixture does not run automatically.

Incorrect print message string.

The fixture runs automatically for each function with autouse=True and scope='function'. The print statement shows the setup message.

Practice

1. What is the main purpose of an autouse fixture in pytest?

easy

A. To run the fixture automatically for all tests without explicitly adding it as a parameter

B. To skip the fixture during test execution

C. To run the fixture only when explicitly requested in the test

D. To disable all fixtures in the test file

Solution

1. Step 1: Understand what autouse means in pytest

   An autouse fixture runs automatically for every test in its scope without needing to be listed as a parameter.

2. Step 2: Compare options with this behavior

   Only To run the fixture automatically for all tests without explicitly adding it as a parameter describes this automatic running behavior correctly.

3. Final Answer:

   To run the fixture automatically for all tests without explicitly adding it as a parameter -> Option A

4. Quick Check:

   Autouse = automatic run without listing [OK]

Hint: Autouse means automatic use without listing in test [OK]

Common Mistakes:

• Thinking autouse disables the fixture
• Believing autouse requires explicit test parameters
• Confusing autouse with skipping tests

2. Which of the following is the correct way to declare an autouse fixture in pytest?

easy

A. @pytest.fixture(auto=True)
def setup():
pass

B. @pytest.fixture(autouse=True)
def setup():
pass

C. @pytest.autouse()
def setup():
pass

D. @pytest.usefixture(autouse=True)
def setup():
pass

Solution

1. Step 1: Recall correct syntax for autouse fixture

   The correct decorator is @pytest.fixture with the argument autouse=True.

2. Step 2: Check each option's syntax

   Only @pytest.fixture(autouse=True) def setup(): pass uses @pytest.fixture(autouse=True) correctly. Others use invalid decorators or wrong argument names.

3. Final Answer:

   @pytest.fixture(autouse=True) def setup(): pass -> Option B

4. Quick Check:

   Use @pytest.fixture(autouse=True) for autouse [OK]

Hint: Remember: autouse is a parameter in @pytest.fixture [OK]

Common Mistakes:

• Using @pytest.autouse decorator which does not exist
• Writing autouse as auto=True
• Using @pytest.usefixture instead of @pytest.fixture

3. Given the code below, what will be the output when running pytest?

import pytest

@pytest.fixture(autouse=True)
def setup():
    print('Setup runs')


def test_one():
    print('Test one running')


def test_two():
    print('Test two running')

medium

A. Test one running\nTest two running

B. Setup runs\nSetup runs\nTest one running\nTest two running

C. Setup runs\nTest one running\nSetup runs\nTest two running

D. Setup runs\nTest one running\nTest two running

Solution

1. Step 1: Understand autouse fixture behavior

   The autouse fixture runs automatically before each test function in the module.

2. Step 2: Trace the print statements during test runs

   For test_one: 'Setup runs' then 'Test one running'. For test_two: 'Setup runs' then 'Test two running'.

3. Final Answer:

   Setup runs\nTest one running\nSetup runs\nTest two running -> Option C

4. Quick Check:

   Autouse runs before each test = output B [OK]

Hint: Autouse fixture runs before every test automatically [OK]

Common Mistakes:

• Assuming fixture runs only once
• Ignoring print inside fixture
• Thinking tests run without setup prints

4. What is wrong with the following autouse fixture code?

import pytest

@pytest.fixture(autouse=True)
def setup():
    print('Setup')

@pytest.fixture
def test_data():
    return 42


def test_example(test_data):
    assert test_data == 42

medium

A. There is no error; the code works correctly

B. The test_data fixture cannot be used with autouse fixtures

C. The autouse fixture setup() does not yield or return, so cleanup is impossible

D. The autouse fixture setup() must accept a parameter

Solution

1. Step 1: Review fixture definitions and usage

   setup() is an autouse fixture that runs automatically and prints 'Setup'. test_data() is a normal fixture returning 42.

2. Step 2: Check if any syntax or usage errors exist

   Both fixtures are valid. Autouse fixtures do not need parameters or yield unless cleanup is needed. test_example uses test_data correctly.

3. Final Answer:

   There is no error; the code works correctly -> Option A

4. Quick Check:

   Autouse fixture without yield is valid [OK]

Hint: Autouse fixtures can be simple setup without yield [OK]

Common Mistakes:

• Expecting autouse fixtures must yield for cleanup
• Thinking autouse conflicts with other fixtures
• Assuming autouse fixtures need parameters

5. You want an autouse fixture to run once per test class, not before every test method. Which scope value should you use with @pytest.fixture(autouse=True)?

hard

A. "session"

B. "module"

C. "function"

D. "class"

Solution

1. Step 1: Understand pytest fixture scopes

   Scope "function" runs before each test function, "class" runs once per test class, "module" once per module, "session" once per test session.

2. Step 2: Match desired behavior to scope

   To run once per test class, use scope="class" with autouse=True.

3. Final Answer:

   "class" -> Option D

4. Quick Check:

   Scope "class" runs once per test class [OK]

Hint: Use scope='class' for autouse fixture once per test class [OK]

Common Mistakes:

• Using default scope 'function' which runs before every test
• Confusing 'module' with 'class' scope
• Using 'session' which runs too broadly