unit-test-json-serialization

Validate POJO JSON serialization and deserialization with Jackson and Spring's @JsonTest.

322|37|Updated Oct 21, 2025

Search Tags:#json #serialization #deserialization #json-test #jackson

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npx skills add https://github.com/giuseppe-trisciuoglio/developer-kit --skill unit-test-json-serialization

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Please help me install this Agent Skill.
Skill: unit-test-json-serialization
Source: https://github.com/giuseppe-trisciuoglio/developer-kit/tree/main/skills/junit-test/unit-test-json-serialization
Command: npx skills add https://github.com/giuseppe-trisciuoglio/developer-kit --skill unit-test-json-serialization

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Validates JSON serialization/deserialization behavior and Jackson configuration using @JsonTest.

Core Features & Use Cases

Verify correct JSON mapping for DTOs, including date and nested structures.
Ensure custom serializers/deserializers function correctly.
Fast tests that do not require full Spring context.

Quick Start

Use @JsonTest with JacksonTester to assert serialized JSON structure and values.

Frequently Asked Questions about unit-test-json-serialization

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I test JSON serialization with Jackson in Spring?▼

Use @JsonTest with JacksonTester to validate JSON serialization and deserialization of POJOs. @JsonTest provides a lightweight test context that loads only Jackson configuration without the full Spring context, enabling fast assertion of serialized JSON structure, field mapping, and values using AssertJ and JsonPath.

Can I test custom Jackson serializers and deserializers?▼

Yes. @JsonTest supports custom serializers and deserializers, allowing you to verify they correctly transform POJOs to JSON and parse JSON back to objects with proper handling of field names, nested structures, and null values without launching the full Spring context.

What's the best way to validate DTO JSON mapping and field naming?▼

Use @JsonTest with JacksonTester to assert that DTOs serialize with correct field names, including date formats and nested object structures. This approach catches property-naming mismatches and ensures Jackson configuration applies correctly before integration testing.

Do I need a full Spring context to test JSON serialization?▼

No. @JsonTest provides a focused test slice that loads only Jackson and JSON configuration, making serialization tests fast and lightweight. This is ideal when you only need to validate JSON mapping behavior without database, web layer, or other Spring components.

How do I handle null values and edge cases in JSON serialization tests?▼

@JsonTest with AssertJ and JsonPath lets you assert null handling, missing fields, and nested object behavior in serialized JSON. You can verify Jackson's configuration for null inclusion, empty collections, and field omission to ensure consistent deserialization.