unit-test-config-properties

name	unit-test-config-properties
description	Provides patterns for unit testing `@ConfigurationProperties` classes with `@ConfigurationPropertiesTest`. Validates property binding, tests validation constraints, verifies default values, checks type conversions, and mocks property sources for Spring Boot configuration properties. Use when testing application configuration binding, validating YAML or application.properties files, verifying environment-specific settings, or testing nested property structures.
allowed-tools	Read, Write, Bash, Glob, Grep

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

• Testing @ConfigurationProperties property binding
• Testing property name mapping and type conversions
• Validating configuration with @NotBlank, @Min, @Max, @Email constraints
• Testing environment-specific configurations (dev, prod)
• Testing nested property structures and collections