@Tag for categorization in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @Tag annotation in JUnit?

The @Tag annotation is used to categorize tests in JUnit. It helps group tests so you can run or exclude specific categories easily.

intermediate

How do you apply multiple tags to a single test method in JUnit?

You apply multiple @Tag annotations by adding them above the test method, each with a different tag name. For example:<br>

@Tag("fast")<br>@Tag("database")<br>void testMethod() { ... }

beginner

True or False: @Tag annotations can be used on test classes as well as test methods.

True. You can put <code>@Tag</code> on a test class to tag all tests inside it, or on individual test methods for more specific categorization.

intermediate

How can you run only tests with a specific tag using JUnit?

You configure your test runner or build tool (like Maven or Gradle) to include only tests with a specific @Tag. For example, in Maven Surefire plugin, you can specify -Dgroups=fast to run tests tagged with @Tag("fast").

beginner

What is a practical example of using @Tag in a real project?

You might tag tests as @Tag("integration") for slow tests that hit a database, and @Tag("unit") for fast, isolated tests. This way, you can run only unit tests during development for speed, and run integration tests separately.

What does the @Tag annotation do in JUnit?

A Marks a test as ignored

B Defines the order of test execution

C Categorizes tests for selective execution

D Specifies the test timeout

@Tag is used to group tests so you can run or exclude them by category.

Can you apply multiple @Tag annotations to a single test method?

A No, tags must be applied at class level only

B No, only one tag is allowed

C Yes, but only if tags are comma-separated in one annotation

D Yes, by adding multiple <code>@Tag</code> annotations

JUnit allows multiple @Tag annotations on the same method to assign multiple categories.

Where can @Tag annotations be placed?

A Only on test methods

B On both test classes and test methods

C Only on the test suite

D Only on test classes

@Tag can be used on classes to tag all tests inside, or on individual methods.

How do you run tests with a specific tag using Maven?

A Use <code>-Dgroups=tagName</code>

B Use <code>-Dtest=tagName</code>

C Use <code>-Dtags=tagName</code>

D Use <code>-DincludeTags=tagName</code>

Maven Surefire plugin uses -Dgroups=tagName to run tests with that tag.

Why is tagging tests useful in a project?

A To speed up test runs by selecting relevant tests

B To automatically fix failing tests

C To generate test data

D To encrypt test results

Tagging helps run only needed tests, saving time during development or CI.

Explain how you would use @Tag annotations to organize tests in a JUnit project.

Think about grouping tests for easier execution control.

Describe the steps to run only tests with a specific tag using a build tool like Maven.

Focus on how tagging connects with test execution commands.