unit-test-config-properties

SKILL.md

Test Spring @ConfigurationProperties bindings, validation, and type conversions without full context startup.

Use ApplicationContextRunner to test property binding in isolation, covering simple properties, nested structures, collections, and type conversions

Verify validation constraints with @Validated annotations, ensuring invalid values fail appropriately and valid configurations pass

Test default values, profile-specific configurations, and property name mapping (kebab-case to camelCase conversion)

Covers Duration, DataSize, List, Map, and Charset type conversions with practical examples for each

Unit Testing Configuration Properties and Profiles

Overview

This skill provides patterns for unit testing @ConfigurationProperties bindings, environment-specific configurations, and property validation using JUnit 5. Covers testing property name mapping, type conversions, validation constraints, nested structures, and profile-specific configurations without full Spring context startup.

Key validation checkpoints:

Property prefix matches between @ConfigurationProperties and test properties

Validation triggers on @Validated classes with invalid values

Type conversions work for Duration, DataSize, collections, and maps

When to Use