How to Auto-Request Pytest Fixtures Using Autouse

With fixture autouse, you can define a fixture that automatically runs before each test method, eliminating the need for manual fixture invocation in each test function.

Autouse in Pytest Fixtures

“Autouse” is an advanced feature of Pytest Fixtures that enables your test functions to automatically utilize a fixture without explicitly requesting it.

An autouse fixture is established by setting the autouse=True parameter.

import pytest  
  
@pytest.fixture(autouse=True)  
def set_number():  
    return 50  
  
def test_example(set_number):  
    # Your test code here  
    print("Executing the test")  
    assert set_number == 50

In the provided code snippet, an autouse fixture named set_number() has been crafted to execute prior to the test function test_example().

The autouse fixture set_number() returns the value 50, which is then utilized by the test function test_example(). Note - you still need to pass the fixture to the test function.

Parameterizing Autouse Fixtures

To parameterize an autouse fixture, you can use the @pytest.mark.parameterize marker.

Disabling Autouse

Sometimes we need to disable an autouse fixture for a specific test function so the fixture may not interrupt the test or perhaps you wish to isolate the test from the fixture.

There are 2 ways to disable an autouse fixture,

The first and easiest way is to remove the autouse=True parameter from the fixture. This will disable the autouse fixture for all the test functions.

The second (more manual) way is to use the @pytest.mark.skip decorator to disable the autouse fixture for a specific test function.

Creating Order For Fixture Execution

To create an order of fixture execution, just request the previous fixture with the later fixture. Let’s see an example to make the concept easier,

import pytest
 
@pytest.fixture(autouse=True, scope="function")
def b():
    print("I'm first")
    pass
 
@pytest.fixture(scope="function")
def a(b):
    print("I'm Second")
    pass

As fixture a requests fixture b, fixture a is unable to run until fixture b completes its execution. So, here b will be executed before a.