---
name: spring-boot-testing-8114d61e400a
description: Write unit, integration, and slice tests for Spring Boot 3 applications. Use when writing unit tests, integration tests, or slice tests for Spring Boot 3 applications.
metadata:
  triggers:
    files:
    - '**/*Test.java'
    keywords:
    - webmvctest
    - datajpatest
    - testcontainers
    - assertj
---
# Spring Boot Testing Standards

## **Priority: P0 (CRITICAL)**

## Core Rule Anchors

- **`[BE-TEST-01]` Parameterized Tests for Equivalent Cases**: Prefer `@ParameterizedTest` (`@CsvSource`, `@MethodSource`) when methods have multiple equivalent inputs or boundary permutations. Distinct scenarios may stay separate test methods. Reviewers must not demand parameterized rewrites without a behavioral gap.
- **`[BE-TEST-02]` Ban on Brittle DB Mock String Matching**: Do not use string-matching mocks for raw SQL queries. Test pure domain calculations directly, or use `Testcontainers` for database repository verification.
- **`[BE-TEST-03]` Ban on Shallow Assertions**: Never assert only `assertThat(result).isNotNull()` without inspecting domain fields, status codes, and invariants.
- **`[BE-TEST-04]` Ban on Pass-Through Interface Mocks**: Repositories and service handlers must test contract compliance and error mapping. Ban 1:1 pass-through mock echoing without contract assertions.
- **`[BE-TEST-05]` Bug-First Regression Lock**: Every PR fixing a bug ticket or with title `fix(...)` must introduce a test reproducing the defect prior to the fix.

## Follow TDD Workflow

1. **Red**: Write failing test (e.g., `returns 404`) (`[BE-TEST-05]`).
2. **Green**: Implement minimal code to pass.
3. **Refactor**: Clean up while keeping tests green (`[BE-TEST-01]`).
4. **Coverage**: Diagnostic and project-configured; verify risk-weighted critical paths rather than padding code for an arbitrary percentage.

## Write Slice and Integration Tests

- **Real Infrastructure (`[BE-TEST-02]`)**: Use **Testcontainers** for DB/Queues. Avoid H2/Embedded.
- **Assertions (`[BE-TEST-03]`)**: Use **AssertJ** (`assertThat`) over JUnit assertions; avoid shallow checks.
- **Isolation (`[BE-TEST-04]`)**: Use `@MockBean` for downstream dependencies in Slice Tests; avoid pass-through mock echoing.

See [implementation examples](references/implementation.md) for WebMvcTest slice tests and Testcontainers integration tests.

## Anti-Patterns

- **`[BE-TEST-01]` Stylistic parameterized rewrites**: Do not demand parameterized refactoring of passing tests without a behavioral gap.
- **`[BE-TEST-02]` Brittle DB mock string matching**: Do not match raw SQL strings in mocks; use Testcontainers.
- **`[BE-TEST-03]` Shallow assertions**: Never assert only `assertThat(result).isNotNull()` without inspecting domain fields or status codes.
- **`[BE-TEST-04]` Pass-through mock echoing**: Ban 1:1 pass-through mock echoing without contract assertions.
- **`[BE-TEST-05]` Bug fix without reproduction test**: Ban bug fixes without a regression test.
- **No Dirty Contexts**: Avoid @MockBean in base classes; it reloads context per test.
- **No network I/O in tests**: Mock external calls with WireMock.
- **No System.out in tests**: Use AssertJ assertions instead.
## References

- [Implementation Examples](references/implementation.md)

---
Source attribution: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: HoangNguyen0403
Original project: https://github.com/HoangNguyen0403/agent-skills-standard
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Development & Engineering
Roles: Backend Developer, DevOps / SRE, QA / Test Engineer
Specialties: Backend, Cross Platform, Testing
Tools: Assertj, Testcontainers
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 0f9fbbb199846af14a4948075b958c265971280e1f4bc9f159bf5ca1503c66ff