Parallel test execution in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run tests in parallel using threads.

Testing Fundamentals

from concurrent.futures import ThreadPoolExecutor

def run_tests():
    with ThreadPoolExecutor(max_workers=[1]) as executor:
        executor.map(run_single_test, test_cases)

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

A5

B10

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 means no parallelism, only sequential execution.

Using 0 causes an error.

Setting max_workers=10 allows running up to 10 tests in parallel threads.

2fill in blank

medium

Complete the code to wait for all parallel tests to finish before proceeding.

Testing Fundamentals

futures = [executor.submit(run_single_test, test) for test in test_cases]
for future in [1]:
    future.result()

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

Aexecutor

Bresults

Ctest_cases

Dfutures

Attempts:

3 left

💡 Hint

Common Mistakes

Looping over test_cases instead of futures.

Using executor as iterable causes error.

Iterating over futures and calling result() waits for each test to complete.

3fill in blank

hard

Fix the error in the code to correctly run tests in parallel using multiprocessing.

Testing Fundamentals

from multiprocessing import Pool

def run_parallel_tests():
    with Pool([1]) as pool:
        results = pool.map(run_single_test, test_cases)

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

A4

B'4'

C-1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using zero or negative numbers causes errors.

Passing a string instead of an integer.

Using a positive integer like 4 sets the number of worker processes correctly.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps test names to their results after parallel execution.

Testing Fundamentals

results = {test[1]: result for test, result in zip(test_cases, [2])}

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

A.name

Bresults

Cpool.map(run_single_test, test_cases)

D.id

Attempts:

3 left

💡 Hint

Common Mistakes

Using .id instead of .name for test identifier.

Using a variable that does not hold results.

Accessing test.name gets the test name, and pool.map(...) runs tests in parallel returning results.

5fill in blank

hard

Fill all three blanks to filter and run only failed tests in parallel, collecting their names and results.

Testing Fundamentals

failed_tests = [test for test in test_cases if test.status == [1]]
results = {test.[2]: res for test, res in zip(failed_tests, pool.[3](run_single_test, failed_tests))}

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

A'failed'

Bname

Cmap

D'passed'

Attempts:

3 left

💡 Hint

Common Mistakes

Filtering for 'passed' instead of 'failed'.

Using wrong attribute instead of 'name'.

Using pool.submit instead of pool.map.

We filter tests with status 'failed', access their name, and use pool.map to run them in parallel.

Practice

1. What is the main benefit of parallel test execution in software testing?

easy

A. It automatically fixes bugs found during testing.

B. It ensures tests run one after another to avoid conflicts.

C. It runs multiple tests at the same time to save testing time.

D. It slows down tests to check for memory leaks.

Solution

1. Step 1: Understand parallel execution purpose

   Parallel test execution means running tests simultaneously, not sequentially.

2. Step 2: Identify the main benefit

   Running tests at the same time saves overall testing time and speeds feedback.

3. Final Answer:

   It runs multiple tests at the same time to save testing time. -> Option C

4. Quick Check:

   Parallel execution = faster testing [OK]

Hint: Parallel means tests run together, saving time [OK]

Common Mistakes:

• Confusing parallel with sequential execution
• Thinking parallel fixes bugs automatically
• Assuming parallel slows down tests

2. Which of the following is the correct way to enable parallel test execution in a test framework configuration?

easy

A. enableParallelExecution = false

B. runTestsSequentially = true

C. testMode = singleThread

D. parallel = true

Solution

1. Step 1: Identify enabling parallel execution

   Setting parallel = true typically enables parallel runs in configs.

2. Step 2: Check other options

   Options A, B, and D disable or prevent parallel execution.

3. Final Answer:

   parallel = true -> Option D

4. Quick Check:

   Enable parallel = true [OK]

Hint: Look for 'parallel = true' to enable parallel runs [OK]

Common Mistakes:

• Using flags that disable parallel execution
• Confusing sequential and parallel settings
• Misreading boolean values

3. Consider this pseudocode for running tests in parallel:

start test1
start test2
wait for test1
wait for test2
print('All tests done')

What will be the output if both tests pass quickly?

medium

A. test1
test2

B. All tests done

C. Error: tests cannot run in parallel

D. No output

Solution

1. Step 1: Understand parallel start

   Both tests start without waiting, so they run at the same time.

2. Step 2: Wait for both tests to finish

   The code waits for test1 and test2 to complete before printing.

3. Final Answer:

   All tests done -> Option B

4. Quick Check:

   Wait then print = 'All tests done' [OK]

Hint: Wait for all tests before printing output [OK]

Common Mistakes:

• Assuming output prints before tests finish
• Thinking tests run sequentially
• Expecting test names printed automatically

4. You configured parallel test execution but notice tests fail due to shared data conflicts. What is the best way to fix this?

medium

A. Make tests independent by avoiding shared data or using separate data copies.

B. Run tests sequentially instead of parallel.

C. Ignore failures as they are caused by parallelism.

D. Increase the number of parallel threads.

Solution

1. Step 1: Identify cause of failure

   Failures happen because tests share data and interfere with each other.

2. Step 2: Fix by isolating tests

   Making tests independent or using separate data copies avoids conflicts.

3. Final Answer:

   Make tests independent by avoiding shared data or using separate data copies. -> Option A

4. Quick Check:

   Isolate tests to fix conflicts [OK]

Hint: Avoid shared data to fix parallel test conflicts [OK]

Common Mistakes:

• Ignoring failures caused by data conflicts
• Just reducing parallel threads without fixing data
• Assuming parallel always works without changes

5. You have 10 independent tests that each take 1 minute to run sequentially. Your test framework supports running 5 tests in parallel. How long will the total test run take if you use parallel execution correctly?

hard

A. 2 minutes

B. 5 minutes

C. 10 minutes

D. 1 minute

Solution

1. Step 1: Calculate sequential time

   Running 10 tests one by one takes 10 minutes (10 x 1 minute).

2. Step 2: Calculate parallel batches

   With 5 tests running at once, tests run in 2 batches (10 / 5 = 2).

3. Step 3: Calculate total parallel time

   Each batch takes 1 minute, so total time is 2 minutes.

4. Final Answer:

   2 minutes -> Option A

5. Quick Check:

   10 tests / 5 parallel = 2 minutes [OK]

Hint: Divide tests by parallel threads for total time [OK]

Common Mistakes:

• Assuming parallel time equals single test time
• Multiplying instead of dividing tests by threads
• Ignoring batch count in calculation