unit-test-json-serialization

Unit testing JSON serialization and deserialization with Spring's @JsonTest and Jackson. Provides patterns for unit testing JSON serialization and deserialization using Spring's @JsonTest and Jackson. Covers POJO mapping, custom serializers, field name mappings, nested objects, date/time formatting, and polymorphic types. When a JSON test fails, follow this workflow: Validation checkpoint after fixing : Re-run the test — if it passes, write a complementary test for the opposite case (e.g., if you fixed null handling, add a test for non-null values to prevent regression). - Covers serialization/deserialization of POJOs, custom serializers/deserializers, field name mappings with @JsonProperty , and null handling using JacksonTester for type-safe assertions - Includes patterns for testing nested objects, lists, date/time formatting, and polymorphic types with @JsonTypeInfo - Provides Maven and Gradle setup, best practices for avoiding circular references and null inclusion issues, and troubleshooting guidance for common Jackson configuration problems - Uses @JsonTest annotation for lightweight JSON-focused test context without full Spring application startup - Testing JSON serialization/deserialization of DTOs - Verifying custom Jackson serializers/deserializers - Validating @JsonProperty , @JsonIgnore , and field name mappings - Testing date/time format handling (LocalDateTime,...