Factory fixtures in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple pytest fixture that returns a user name.

PyTest

import pytest

@pytest.fixture
def [1]():
    return "Alice"

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

Auser_name

Busername

Cname

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using a name that is too generic or not descriptive.

Forgetting to add the @pytest.fixture decorator.

The fixture function must be named so tests can use it. Here, user_name is the correct fixture name.

2fill in blank

medium

Complete the code to use the fixture in a test function.

PyTest

def test_greeting([1]):
    assert [1] == "Alice"

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

Auser

Buser_name

Cusername

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different parameter name than the fixture name.

Not including the fixture as a parameter in the test function.

The test function parameter must match the fixture name to receive its value. Here, user_name is the parameter that receives the fixture value.

3fill in blank

hard

Fix the error in the fixture that should return a dictionary with user info.

PyTest

@pytest.fixture
def user_info():
    return [1]"name": "Bob", "age": 30}

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

A{

B[

C(

D{"

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or parentheses instead of curly braces.

Missing the opening brace for the dictionary.

The fixture must return a dictionary. Dictionaries start with a curly brace {. The correct answer is {.

4fill in blank

hard

Fill both blanks to create a fixture that returns a list of user names and a test that uses it.

PyTest

@pytest.fixture
def user_list():
    return [1]"Alice", "Bob", "Charlie"[2]

def test_user_count(user_list):
    assert len(user_list) == 3

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

A[

B(

C]

D)

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of square brackets for lists.

Mismatching opening and closing brackets.

The fixture returns a list, which uses square brackets []. So the blanks are filled with [ and ].

5fill in blank

hard

Complete the code to create a fixture that returns a dictionary with user details and a test that checks the user's age.

PyTest

@pytest.fixture
def user_data():
    return {"name": "Eve", [1]: 28}

def test_user_age(user_data):
    assert user_data["age"] == 28

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

A{

B"age"

C}

D[

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to quote dictionary keys.

Using square brackets instead of curly braces for dictionaries.

Not closing the dictionary properly.

The fixture returns a dictionary, so it starts with { and ends with }. The key for age must be quoted as "age".

Practice

1. What is the main purpose of a factory fixture in pytest?

easy

A. To run tests in parallel automatically

B. To create reusable test data with flexible parameters

C. To generate test reports in HTML format

D. To mock external API calls during tests

Solution

1. Step 1: Understand what factory fixtures do

   Factory fixtures return a function that can create test data with different parameters as needed.

2. Step 2: Compare with other options

   Running tests in parallel, generating reports, or mocking APIs are different pytest features, not factory fixtures.

3. Final Answer:

   To create reusable test data with flexible parameters -> Option B

4. Quick Check:

   Factory fixture = reusable flexible test data creator [OK]

Hint: Factory fixtures build test data functions fast [OK]

Common Mistakes:

• Confusing factory fixtures with mocking
• Thinking factory fixtures run tests
• Assuming factory fixtures generate reports

2. Which of the following is the correct way to define a simple factory fixture in pytest?

easy

A. @pytest.fixture
def user_factory(name):
return {'name': name}

B. def user_factory():
return {'name': 'default'}

C. @pytest.fixture
def user_factory():
def create_user(name):
return {'name': name}
return create_user

D. @pytest.fixture
def user_factory():
return {'name': 'default'}

Solution

1. Step 1: Identify factory fixture structure

   A factory fixture returns a function that accepts parameters to create test data dynamically.

2. Step 2: Check each option

   @pytest.fixture def user_factory(): def create_user(name): return {'name': name} return create_user defines a fixture returning a function that takes a name and returns a dict, which is correct. Options A, C, and D do not return a function, so they are not factory fixtures.

3. Final Answer:

   @pytest.fixture def user_factory(): def create_user(name): return {'name': name} return create_user -> Option C

4. Quick Check:

   Factory fixture = fixture returning a function [OK]

Hint: Factory fixtures return a function inside the fixture [OK]

Common Mistakes:

• Returning data directly instead of a function
• Missing @pytest.fixture decorator
• Defining fixture with parameters directly

3. Given the following pytest code, what will be the output of the test?

@pytest.fixture
def number_factory():
    def create_number(x):
        return x * 2
    return create_number

def test_double(number_factory):
    result = number_factory(5)
    assert result == 10
    print(result)

medium

A. Test passes and prints 10

B. Test fails with AssertionError

C. SyntaxError due to fixture usage

D. Test passes but prints 5

Solution

1. Step 1: Understand the factory fixture behavior

   The fixture returns a function that doubles the input number.

2. Step 2: Analyze the test function

   The test calls number_factory(5), which returns 5 * 2 = 10, then asserts result == 10, which is true, so test passes and prints 10.

3. Final Answer:

   Test passes and prints 10 -> Option A

4. Quick Check:

   5 * 2 = 10, assertion true [OK]

Hint: Factory fixture returns function; call it with argument [OK]

Common Mistakes:

• Thinking fixture itself is called with argument
• Expecting print output to fail test
• Confusing assertion logic

4. Identify the error in this factory fixture code and how to fix it:

@pytest.fixture
def item_factory():
    def create_item(name, price):
        return {'name': name, 'price': price}
    return create_item

def test_item(item_factory):
    item = item_factory('Book')
    assert item['price'] == 10

medium

A. The fixture is missing @pytest.mark.parametrize decorator; add it.

B. The fixture should not return a function; fix by returning a dict directly.

C. The test should not use the fixture as a function; fix by removing parentheses.

D. The factory function is missing the 'price' argument; fix by passing price when calling.

Solution

1. Step 1: Check the factory function parameters

   The factory function create_item expects two arguments: name and price.

2. Step 2: Analyze the test call

   The test calls item_factory('Book') with only one argument, missing price, causing an error or wrong data.

3. Final Answer:

   The factory function is missing the 'price' argument; fix by passing price when calling. -> Option D

4. Quick Check:

   Factory args must match call args [OK]

Hint: Match factory function parameters with call arguments [OK]

Common Mistakes:

• Calling factory with fewer arguments than defined
• Returning dict directly instead of function
• Misusing fixture as a simple variable

5. You want to create a factory fixture that builds user dictionaries with optional age and default country='USA'. Which of the following implementations correctly achieves this?

hard

A. @pytest.fixture
def user_factory():
def create_user(name, age=None, country='USA'):
return {'name': name, 'age': age, 'country': country}
return create_user

B. @pytest.fixture
def user_factory(name, age=None, country='USA'):
return {'name': name, 'age': age, 'country': country}

C. @pytest.fixture
def user_factory():
return {'name': 'default', 'age': None, 'country': 'USA'}

D. @pytest.fixture
def user_factory():
def create_user(name, age, country):
return {'name': name, 'age': age, 'country': country}
return create_user

Solution

1. Step 1: Understand factory fixture with optional/default parameters

   The factory fixture should return a function that accepts parameters with defaults for optional values.

2. Step 2: Evaluate each option

   @pytest.fixture def user_factory(): def create_user(name, age=None, country='USA'): return {'name': name, 'age': age, 'country': country} return create_user correctly defines a fixture returning a function with default age=None and country='USA'. @pytest.fixture def user_factory(name, age=None, country='USA'): return {'name': name, 'age': age, 'country': country} is not a factory fixture because it takes parameters directly. @pytest.fixture def user_factory(): return {'name': 'default', 'age': None, 'country': 'USA'} returns a fixed dict, not a factory. @pytest.fixture def user_factory(): def create_user(name, age, country): return {'name': name, 'age': age, 'country': country} return create_user requires all parameters without defaults, so age and country are not optional.

3. Final Answer:

   @pytest.fixture def user_factory(): def create_user(name, age=None, country='USA'): return {'name': name, 'age': age, 'country': country} return create_user -> Option A

4. Quick Check:

   Factory fixture returns function with defaults [OK]

Hint: Factory fixture returns function with default parameters [OK]

Common Mistakes:

• Defining fixture with parameters directly
• Not providing default values for optional args
• Returning fixed data instead of a function