**vaessl: Test strategy**

# Spring Boot Test Environment
1. Environment Parity

    Instead of testing against a mocked database or the development database, I created a mirrored test container. This allows the application to perform JPA operations against a real PostgreSQL instance that matches the production engine but uses a different port (5434) and database name (vaessl_test).

2. Profile-Driven Configuration

    I utilized the Spring Profiles mechanism. By tagging the test class with @ActiveProfiles("test"), Spring Boot ignores the standard application.yaml for specific keys and prioritizes src/test/resources/application-test.yaml.

    The configuration is moved out of the Java code and into YAML. This follows the "Separation of Concerns" principle.

    The file is placed in src/test/resources (a sibling to src/test/java). This is the standard Gradle "SourceSet" layout, ensuring the build tool automatically packages these settings only during the test phase.

3. Gradle Test Lifecycle

    I corrected the dependency graph in build.gradle.kts. While the Initializr provides "test slices" (like data-jpa-test), a full integration test requires the Spring Boot Starter Test core.

    This starter provides the YAML parsing engine and the SpringBootContextLoader.

# Frontend Test environment

1. The Vitest Stack

    - Vitest: providing a unified configuration for both the development server and the test runner.

    - jsdom: Provides a lightweight browser environment in Node.js.

    - React Testing Library: Ensures tests are written from the user's perspective (DOM-based) rather than implementation details.

2. Dynamic Environment Configuration

    The vitest.config.ts is configured to be environment-aware. By using loadEnv, the test runner can access variables from .env files, allowing us to:

    - Dynamically set the Server Port (51204).

    - Handle Allowed Hosts (crucial for code-server or LXC environments where the public URL might change).

    - Inject environment-specific keys into the test.env context.

3. TDD Workflow (Red-Green-Refactor)
    
    The environment is optimized for a fast feedback loop.

    - npm run test: Runs Vitest in "Watch Mode," re-triggering tests instantly upon file changes.

    - npm run test:ui: Launches the Vitest UI, providing a visual graph of test suites and real-time failure reports.