assertTimeout for performance in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assert that the method finishes within 1 second.

JUnit

assertTimeout(Duration.ofSeconds([1]), () -> methodToTest());

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

A10

B1

C0

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a timeout value too large or zero, which defeats the purpose of performance testing.

The assertTimeout method checks that methodToTest() completes within the given duration. Here, Duration.ofSeconds(1) means 1 second.

2fill in blank

medium

Complete the code to assert that the lambda expression finishes within 500 milliseconds.

JUnit

assertTimeout(Duration.ofMillis([1]), () -> someFunction());

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

A1000

B50

C500

D1500

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing milliseconds with seconds and using Duration.ofSeconds() instead.

Using Duration.ofMillis(500) sets the timeout to 500 milliseconds, ensuring someFunction() completes quickly.

3fill in blank

hard

Fix the error in the code by completing the blank with the correct import for Duration.

JUnit

import [1];

assertTimeout(Duration.ofSeconds(2), () -> processData());

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

Ajava.time.Duration

Bjava.io.Duration

Cjava.lang.Duration

Djava.util.Duration

Attempts:

3 left

💡 Hint

Common Mistakes

Importing from the wrong package causes compilation errors.

The Duration class is in the java.time package, so the correct import is java.time.Duration.

4fill in blank

hard

Fill both blanks to assert that the method finishes within 3 seconds and returns the expected value.

JUnit

String result = assertTimeout(Duration.ofSeconds([1]), () -> [2]);
assertEquals("success", result);

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A3

BperformTask()

Cexecute()

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong method name or wrong timeout duration.

The timeout is set to 3 seconds with Duration.ofSeconds(3). The lambda calls performTask() which returns the result to check.

5fill in blank

hard

Fill all three blanks to assert that the method finishes within 200 milliseconds, returns a non-null value, and the result equals "done".

JUnit

var result = assertTimeout(Duration.ofMillis([1]), () -> [2]);
assertNotNull(result);
assertEquals([3], result);

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

A200

BrunProcess()

C"done"

D"completed"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong timeout units or wrong expected string.

The timeout is 200 milliseconds. The method runProcess() is called inside the lambda. The test checks that the result is not null and equals "done".