321-frameworks-spring-boot-testing-unit-tests

321-frameworks-spring-boot-testing-unit-tests is a skill for Claude Code, Codex from jabrena/plinth. It costs 176 tokens per session (821 once invoked), scanned A, original, Apache-2.0.

A guide for testing Spring Boot code with small, focused tests and Mockito, a library for replacing dependencies with controlled test doubles. It also covers tests limited to controllers or JSON handling.

In plain words
What is it for?
Use it to write service unit tests, controller tests, JSON tests, parameterized tests, and deterministic test configuration in Spring Boot 4.
Why use it?
It helps verify services, controllers, and JSON independently, so failures are easier to locate and tests do not need the whole application to start.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to write service unit tests, controller tests, JSON tests, parameterized tests, and deterministic test configuration in Spring Boot 4.

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Install with agentmods
npx agentmods add skills/jabrena/plinth/321-frameworks-spring-boot-testing-unit-tests
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add jabrena/plinth --skill 321-frameworks-spring-boot-testing-unit-tests
Clone the repo
git clone --depth 1 https://github.com/jabrena/plinth

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin 321-frameworks-spring-boot-testing-unit-tests/plugin install 321-frameworks-spring-boot-testing-unit-tests after adding the marketplace above.

Wrote this? Show the measurements

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agentmods badge for 321-frameworks-spring-boot-testing-unit-tests

README.md
[![agentmods](https://agentmods.dev/badge/skills/jabrena/plinth/321-frameworks-spring-boot-testing-unit-tests.svg)](https://agentmods.dev/skills/jabrena/plinth/321-frameworks-spring-boot-testing-unit-tests)
Your own site
<a href="https://agentmods.dev/skills/jabrena/plinth/321-frameworks-spring-boot-testing-unit-tests"><img src="https://agentmods.dev/badge/skills/jabrena/plinth/321-frameworks-spring-boot-testing-unit-tests.svg" alt="Measured on agentmods" height="20"></a>
Per session 176 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 821 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00176 $0.00821
Opus 5 $0.00088 $0.00411
Sonnet 5 $0.00035 $0.00164
Haiku 4.5 $0.00018 $0.00082

Measured 5d ago against content hash 9befe50b0a9e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

321-frameworks-spring-boot-testing-unit-tests scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/321-frameworks-spring-boot-testing-unit-tests/SKILL.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spring Boot Unit Testing with Mockito

Apply Spring Boot unit testing guidelines with Mockito.

What is covered in this Skill?

  • Pure unit tests: @ExtendWith(MockitoExtension.class), @Mock, @InjectMocks for @Service/@Component (no Spring context)
  • Slice tests: @WebMvcTest, @MockitoBean for controllers (Spring Boot 4.0.x — @MockBean removed)
  • @JsonTest for JSON serialization with correct JSON value assertions (extractingJsonPathStringValue, etc.)
  • Parameterized tests: @ParameterizedTest with @CsvSource or @MethodSource over copy-pasted methods
  • Java records for domain objects in tests
  • @TestConfiguration, @ActiveProfiles, @Primary fixed-clock beans for deterministic test setup
  • Modern mocking API: @MockitoBean / @MockitoSpyBean; @MockBean/@SpyBean are deprecated/removed in Boot 4.0.x

Scope: Apply recommendations based on the reference rules and good/bad code examples. For integration tests use @322-frameworks-spring-boot-testing-integration-tests.

Constraints

Before applying any test changes, ensure the project compiles. If compilation fails, stop immediately. After applying improvements, run full verification.

  • MANDATORY: Run ./mvnw compile or mvn compile before applying any change
  • SAFETY: If compilation fails, stop immediately
  • VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
  • BEFORE APPLYING: Read the reference for detailed rules and good/bad patterns
  • EDGE CASE: If request scope is ambiguous, stop and ask a clarifying question before applying changes
  • EDGE CASE: If required inputs, files, or tooling are missing, report what is missing and ask whether to proceed with setup guidance

When to use this skill

  • Review Java code for Spring Boot unit tests
  • Apply best practices for Spring Boot unit tests in Java code
  • Write Mockito-first unit tests for Spring Boot services
  • Avoid unnecessary @SpringBootTest in Spring unit tests
  • Review Spring Boot slice-free unit test design

Read the full file on GitHub · 65 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 65 lines · 176 tokens per session scan A 9befe50b0a9e

Subscribe to this mod's changes

321-frameworks-spring-boot-testing-unit-tests is a skill published in the GitHub repository jabrena/plinth (437 stars, last pushed today), licensed Apache-2.0. It adds 176 tokens to every session and 821 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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