Testing no exception thrown in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assert that no exception is thrown when calling the method.

JUnit

assertDoesNotThrow(() -> [1]());

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AfailMethod

BthrowException

CerrorMethod

DmyMethod

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method that throws an exception inside assertDoesNotThrow.

Forgetting the lambda syntax and writing method call directly.

The assertDoesNotThrow method expects a lambda that calls the method under test. Here, myMethod is the method that should not throw an exception.

2fill in blank

medium

Complete the code to test that no exception is thrown when executing the runnable.

JUnit

assertDoesNotThrow([1]);

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A() -> runnable.run()

Bnew Runnable()

Crunnable.run()

Drunnable

Attempts:

3 left

💡 Hint

Common Mistakes

Passing runnable.run() directly, which executes immediately.

Passing the runnable object instead of a lambda.

The argument to assertDoesNotThrow must be a lambda or executable block. () -> runnable.run() correctly wraps the runnable's run method.

3fill in blank

hard

Fix the error in the test code to correctly assert no exception is thrown.

JUnit

assertDoesNotThrow(() -> [1].execute());

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Atask

Bnull

C123

DSystem

Attempts:

3 left

💡 Hint

Common Mistakes

Passing null causing NullPointerException.

Passing a number or class instead of an object.

The variable task should be an object with an execute() method. Passing null or invalid types causes errors.

4fill in blank

hard

Fill both blanks to assert no exception is thrown when calling the method with argument.

JUnit

assertDoesNotThrow(() -> [1].[2](input));

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Aservice

Bprocess

Cexecute

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping object and method names.

Using methods that do not accept the input argument.

The object service has a method process that takes input. Wrapping this call in a lambda checks no exception is thrown.

5fill in blank

hard

Fill all three blanks to assert no exception is thrown when calling a static method with parameters.

JUnit

assertDoesNotThrow(() -> [1].[2]([3]));

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AUtils

B"test"

CrunTask

D123

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number instead of a string argument.

Calling instance methods on a class name.

The static class Utils has a method runTask that accepts a string parameter. Passing the string "test" as argument inside the lambda checks no exception is thrown.