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Master JUnit with Adaptive AI.

Master JUnit across 18 topics - Foundations, Intermediate, and Advanced - guided by Leyaa's adaptive intelligence.

3Parts

18Topics

137Patterns

35hEst. duration

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JUnit Course

3 - part learning journey

Foundations

6 topics · 47 patterns

Beginner

Intermediate

6 topics · 46 patterns

Intermediate

Advanced

6 topics · 44 patterns

Advanced

Begin Part 1: Foundations

✦ Course Structure

Your JUnit Journey in 3 Parts

Each part builds on the last - a deliberate progression from beginner to advanced.

Beginner

Part 1: Foundations

Covers JUnit Basics and Testing Philosophy, Test Structure, Assertions and 3 more topics.

6Topics

47Patterns

View topics

Intermediate

Part 2: Intermediate

Covers Advanced Parameterized Tests, Assumptions and Conditional Tests, Exception Testing and 3 more topics.

6Topics

46Patterns

View topics

Advanced

Part 3: Advanced

Covers Extensions, Integration Testing Patterns, Test Coverage and Quality and 3 more topics.

6Topics

44Patterns

View topics

Curriculum

Everything You'll Learn

Explore every topic and pattern in the course.

JUnit

3 parts · 18 topics · 137 patterns

Part 1: Foundations6 topics · 47 patterns

Beginner

JUnit Basics and Testing Philosophy

7 patterns

Why JUnit is the standard for Java testing

Unit testing concept

JUnit 4 vs JUnit 5 (Jupiter) differences

Maven dependency setup

Gradle dependency setup

IDE integration (IntelliJ, Eclipse)

First JUnit test

Test Structure

7 patterns

Why test structure ensures clarity

@Test annotation

Test method naming conventions

@DisplayName for readable names

@Disabled for skipping tests

Test class organization

Arrange-Act-Assert pattern

Assertions

9 patterns

Why assertions verify expected outcomes

assertEquals

assertNotEquals

assertTrue and assertFalse

assertNull and assertNotNull

assertSame and assertNotSame

assertThrows for exceptions

assertTimeout for performance

assertAll for grouped assertions

Lifecycle Methods

8 patterns

Why lifecycle hooks manage setup and teardown

Execution order of lifecycle methods

Nested class lifecycle

TestInstance lifecycle per class

Test Organization

8 patterns

Why organization scales test suites

Test classes and naming

@Nested inner classes

@Tag for categorization

@Order for execution order

Test suites with @Suite

Selecting tests by tags and classes

Package-level test organization

Basic Parameterized Tests

8 patterns

Why parameterization reduces test duplication

@ParameterizedTest annotation

@ValueSource for simple values

@NullSource and @EmptySource

@NullAndEmptySource

@EnumSource for enum values

Multiple parameter types

Custom display names for parameters

Part 2: Intermediate6 topics · 46 patterns

Intermediate

Advanced Parameterized Tests

8 patterns

Why advanced sources handle complex data

@CsvSource for inline CSV data

@CsvFileSource for external CSV

@MethodSource for factory methods

@ArgumentsSource with custom providers

Argument conversion

Argument aggregation

Custom argument providers

Assumptions and Conditional Tests

8 patterns

Why assumptions control test execution

assumeTrue and assumeFalse

assumingThat for conditional assertions

@EnabledOnOs for OS-specific tests

@EnabledOnJre for JRE-specific tests

@EnabledIfEnvironmentVariable

@EnabledIfSystemProperty

Custom conditions with @EnabledIf

Exception Testing

7 patterns

Why exception testing validates error handling

assertThrows usage

Checking exception message

Checking exception type hierarchy

Testing no exception thrown

assertDoesNotThrow

Testing multiple exceptions

Mocking with Mockito

9 patterns

Why mocking isolates units under test

Mockito dependency setup

@Mock annotation

@InjectMocks annotation

when().thenReturn() stubbing

when().thenThrow() for exceptions

verify() for interaction verification

Argument matchers (any, eq)

Verification times (times, never, atLeast)

Mocking Advanced

7 patterns

Why advanced mocking handles complex dependencies

@Spy for partial mocking

doReturn and doThrow

Argument captors

Mocking static methods (Mockito 3.4+)

Mocking void methods

Answer interface for dynamic responses

Test Doubles

7 patterns

Why different doubles serve different purposes

Choosing the right test double

Part 3: Advanced6 topics · 44 patterns

Advanced

Extensions

7 patterns

Why extensions customize JUnit behavior

Extension model overview

@ExtendWith annotation

BeforeEachCallback and AfterEachCallback

ParameterResolver extension

TestWatcher for reporting

Custom extensions

Integration Testing Patterns

8 patterns

Why integration tests verify component interaction

Spring Boot @SpringBootTest

@DataJpaTest for repository testing

@WebMvcTest for controller testing

@MockBean for Spring mocking

TestRestTemplate for API testing

Test containers for database testing

In-memory database testing

Test Coverage and Quality

7 patterns

Why coverage measures test completeness

JaCoCo setup and configuration

Line and branch coverage

Coverage reports

Coverage thresholds

Mutation testing concept (PIT)

Code quality gates

Performance and Parallel Execution

6 patterns

Why fast tests enable frequent runs

Parallel test configuration

@Execution annotation

Resource locking with @ResourceLock

Timeout annotations

Test execution time analysis

Best Practices and Patterns

8 patterns

Why patterns improve test quality

Single assertion per test debate

Test independence

Deterministic tests

Testing private methods (should you?)

Builder pattern for test data

Object Mother pattern

Test naming conventions deep dive

CI/CD and Reporting

8 patterns

Why CI integration enables continuous quality

Maven Surefire plugin

Gradle test task

XML and HTML reports

CI pipeline test stage

Test result publishing

Failure notification setup

Flaky test detection

Why Leyaa

Not just a course. A learning intelligence.

Leyaa doesn't just deliver content - it understands where you are, what you need, and how to get you there fastest.

Adaptive Diagnostics

Leyaa identifies which of the 137 patterns you've mastered and which need work - before you waste time on what you already know.

Pattern-Level Precision

Every pattern gets a verdict - Learn, Practice, or Skip - so your study time goes exactly where it counts.

Intelligent Pacing

Leyaa reads your velocity across the whole course and adapts your focus list dynamically, keeping you in the optimal learning zone.

Before & After Visibility

Every assessment creates a snapshot. Retake anytime to see exactly how much you've grown - topic by topic, pattern by pattern.

Learner Autonomy

Leyaa recommends, never restricts. Override any suggestion and explore at your own pace - the system tracks everything regardless.

Clear Learning Path

Foundations → Intermediate → Advanced - a structured journey where each part sets you up perfectly for the next.

JUnit

Ready to master JUnit?
Start your journey today

Start your diagnostic now. Build mastery across all 18 topics in under 15 minutes.

18 Topics

137 Patterns

Personalized roadmap

Master JUnit with Adaptive AI.

Your JUnit Journey in 3 Parts

Everything You'll Learn

JUnit

Not just a course. A learning intelligence.

Ready to master JUnit?Start your journey today

Ready to master JUnit?
Start your journey today