Custom markers in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark the test with a custom marker named 'slow'.

PyTest

import pytest

@pytest.mark.[1]
def test_example():
    assert 1 + 1 == 2

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

Aslow

Bfast

Cskip

Dparametrize

Attempts:

3 left

💡 Hint

Common Mistakes

Using a built-in marker like 'skip' instead of the custom marker 'slow'.

Forgetting to use '@pytest.mark.' before the marker name.

The custom marker 'slow' is added using @pytest.mark.slow before the test function.

2fill in blank

medium

Complete the code to run only tests marked with 'database' using pytest command line option.

PyTest

pytest -m [1]

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

Aslow

Bnetwork

Cskip

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Using a marker name that does not exist on any test.

Omitting the -m option.

To run tests marked with 'database', use pytest -m database.

3fill in blank

hard

Fix the error in the code to register a custom marker 'api' in pytest.ini.

PyTest

[pytest]
markers =
    [1]: mark test as API test

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

Aapi

BAPI

CApi

DapI

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase or mixed case marker names in pytest.ini that don't match the code.

Not registering the marker in pytest.ini causing warnings.

Markers in pytest.ini are case-sensitive and should match the marker used in code exactly. The correct marker is 'api'.

4fill in blank

hard

Fill both blanks to mark a test with 'integration' and skip it conditionally when a variable is False.

PyTest

import pytest

@pytest.mark.[1]
@pytest.mark.skipif(not is_ready, reason='Not ready')
def test_integration():
    assert True

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

Aintegration

Bunit

Cslow

Dskip

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'skip' instead of 'skipif' for conditional skipping.

Using wrong marker names.

The test is marked with 'integration' and uses @pytest.mark.skipif to skip conditionally.

5fill in blank

hard

Fill all three blanks to define and use a custom marker 'performance' with pytest.mark and run only those tests.

PyTest

import pytest

@pytest.mark.[1]
def test_speed():
    assert 100 < 200

# Run tests with: pytest -m [2]

# Register marker in pytest.ini:
#[pytest]
#markers =
#    [3]: mark test as performance test

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

Aperformance

Dslow

Attempts:

3 left

💡 Hint

Common Mistakes

Using different marker names in code and pytest.ini.

Forgetting to register the marker in pytest.ini.

The custom marker 'performance' is used consistently in code, command line, and pytest.ini registration.

Practice

1. What is the main purpose of using custom markers in pytest?

easy

A. To generate test data automatically

B. To change the Python interpreter version

C. To automatically fix test failures

D. To label tests for grouping and selective running

Solution

1. Step 1: Understand what custom markers do

   Custom markers in pytest are used to tag tests with labels for easier management.

2. Step 2: Identify the purpose of these labels

   These labels help run specific groups of tests selectively using the marker name.

3. Final Answer:

   To label tests for grouping and selective running -> Option D

4. Quick Check:

   Custom markers = test grouping [OK]

Hint: Markers tag tests to run groups easily [OK]

Common Mistakes:

• Thinking markers change Python version
• Assuming markers fix test errors automatically
• Confusing markers with test data generation

2. Which of the following is the correct syntax to mark a test with a custom marker named slow?

easy

A. @pytest.mark.slow\ndef test_example(): pass

B. @pytest.slow.mark\ndef test_example(): pass

C. @pytest.mark[slow]\ndef test_example(): pass

D. @pytest.mark('slow')\ndef test_example(): pass

Solution

1. Step 1: Recall pytest marker syntax

   Custom markers use dot notation: @pytest.mark.markername before the test function.

2. Step 2: Match the correct syntax

   @pytest.mark.slow is the correct way to apply the 'slow' marker.

3. Final Answer:

   @pytest.mark.slow\ndef test_example(): pass -> Option A

4. Quick Check:

   Marker syntax = @pytest.mark.name [OK]

Hint: Use dot notation: @pytest.mark.name [OK]

Common Mistakes:

• Using parentheses instead of dot notation
• Using square brackets instead of dot notation
• Placing marker after function name

3. Given the following test file, what will be the output when running pytest -m slow?

import pytest

@pytest.mark.slow
def test_a():
    assert True

def test_b():
    assert True

@pytest.mark.slow
def test_c():
    assert False

medium

A. Runs all tests; test_c fails

B. Runs only test_b; all pass

C. Runs test_a and test_c; test_c fails, test_a passes

D. Runs test_a and test_b; all pass

Solution

1. Step 1: Understand what pytest -m slow does

   This command runs only tests marked with the 'slow' marker.

2. Step 2: Identify marked tests in the code

   test_a and test_c have @pytest.mark.slow, so only these run.

3. Step 3: Check test results

   test_a passes (assert True), test_c fails (assert False).

4. Final Answer:

   Runs test_a and test_c; test_c fails, test_a passes -> Option C

5. Quick Check:

   pytest -m slow runs marked tests only [OK]

Hint: -m runs only tests with that marker [OK]

Common Mistakes:

• Assuming all tests run with -m option
• Ignoring test failures in marked tests
• Running unmarked tests by mistake

4. What is wrong with this pytest marker usage?

import pytest

@pytest.mark.slow()
def test_example():
    assert True

medium

A. Markers should not have parentheses unless parameters are used

B. Marker name must be uppercase

C. The test function must have parameters

D. pytest.mark cannot be used on test functions

Solution

1. Step 1: Check marker syntax

   Markers without parameters should not have parentheses; @pytest.mark.slow() is incorrect.

2. Step 2: Correct usage

   Use @pytest.mark.slow without parentheses for simple markers.

3. Final Answer:

   Markers should not have parentheses unless parameters are used -> Option A

4. Quick Check:

   Use parentheses only with marker args [OK]

Hint: No parentheses for simple markers [OK]

Common Mistakes:

• Adding empty parentheses to markers
• Using uppercase marker names incorrectly
• Thinking markers require function parameters

5. You want to run tests marked as database but exclude those also marked as slow. Which pytest command achieves this?

hard

A. pytest -m "database or slow"

B. pytest -m "database and not slow"

C. pytest -m "not database and slow"

D. pytest -m "database and slow"

Solution

1. Step 1: Understand marker expressions

   pytest supports boolean expressions with markers: and, or, not.

2. Step 2: Formulate the correct expression

   To run tests marked 'database' but exclude 'slow', use "database and not slow".

3. Final Answer:

   pytest -m "database and not slow" -> Option B

4. Quick Check:

   Use boolean logic in -m to include/exclude markers [OK]

Hint: Use boolean logic: -m "marker and not other" [OK]

Common Mistakes:

• Using 'or' instead of 'and not' to exclude
• Misplacing 'not' before the first marker
• Combining markers without quotes