Parallel test execution in Testing Fundamentals - Test Execution Trace

Test Overview

This test demonstrates running two simple tests at the same time (in parallel). It verifies that both tests complete successfully without waiting for each other.

Test Code - unittest with ThreadPoolExecutor

Testing Fundamentals

import unittest
import time
from concurrent.futures import ThreadPoolExecutor

class SimpleTest(unittest.TestCase):
    def test_one(self):
        time.sleep(2)  # Simulate a delay
        self.assertEqual(1 + 1, 2)

    def test_two(self):
        time.sleep(2)  # Simulate a delay
        self.assertTrue('hello'.islower())

if __name__ == '__main__':
    suite = unittest.TestLoader().loadTestsFromTestCase(SimpleTest)
    with ThreadPoolExecutor(max_workers=2) as executor:
        futures = [executor.submit(unittest.TextTestRunner().run, test) for test in suite]
        results = [f.result() for f in futures]
    # Check all tests passed
    assert all(result.wasSuccessful() for result in results), "Some tests failed"

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test suite loads two test methods: test_one and test_two	Two test cases ready to run	-	PASS
2	ThreadPoolExecutor starts and runs test_one and test_two in parallel threads	Both tests running simultaneously, each sleeping for 2 seconds	-	PASS
3	test_one completes and asserts 1 + 1 equals 2	test_one finished successfully	assertEqual(1 + 1, 2)	PASS
4	test_two completes and asserts 'hello' is lowercase	test_two finished successfully	assertTrue('hello'.islower())	PASS
5	Main thread collects results from both tests	Both tests passed	assert all tests passed	PASS

Failure Scenario

Failing Condition: One of the tests fails its assertion or does not complete

Execution Trace Quiz - 3 Questions

What does running tests in parallel help achieve?

A Skip tests that take too long

B Run tests one after another to avoid conflicts

C Run multiple tests at the same time to save time

D Run only one test to reduce errors

Key Result

Running tests in parallel can greatly reduce total test time, but each test must be independent and thread-safe to avoid conflicts.