intermediate · self-paced

JUnit 5, Mockito, and Contract Tests

Layered testing strategy from pure units to consumer-driven contracts without brittle suites.

Cover for JUnit 5, Mockito, and Contract Tests

5 weeks · 6h/week

JPY 72,000

Informational rate—final fees appear on your enrollment agreement.

Request information Money-back policy

Program narrative

Design tests that survive refactors. You will compare classic Mockito patterns with modern stubbing, explore parameterized tests, and publish Pact contracts that catch breaking changes before merge. Includes a ruthless review of flaky tests you bring from work (sanitized).

What ships in the box

  • Mutation testing intro with PiTest on sample services
  • Fixture builders versus object mothers debate with rubric
  • Parallel test execution tuning worksheet
  • Contract testing lab with Pact JVM and broker discussion
  • CI recipe that fails fast on coverage cliffs
  • Checklist for testing asynchronous messaging boundaries
  • Mentor audit of one of your real test files

Outcomes you can describe

  • Cut redundant tests while keeping meaningful coverage signals
  • Explain when to prefer contract tests over brittle integration giants
  • Document a testing policy snippet for your README or wiki
Avatar for Sora Nishimura

Lead mentor

Sora Nishimura

QA reviewer; previously owned CI hygiene for a fintech ledger team.

Cohort questions

IntelliJ or VS Code both work; we provide run configurations for Gradle and Maven samples.

Course artifacts are Java-only; concepts map to Kotlin but we do not grade alternate runtimes.

Browser automation, load testing tools, and security fuzzing pipelines are mentioned but not taught in depth.

Experience notes

Mutation testing week embarrassed our suite—in a useful way. We deleted three tests that never failed.
Kenji · developer in Nagoya