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MDAA Installer Testing

This directory contains comprehensive tests for the MDAA Installer Stack, including both unit tests and snapshot tests.

Test Structure

Unit Tests (mdaa-installer.test.ts)

  • Tests individual components and functionality
  • Validates resource properties and configurations
  • Checks parameter definitions and validation rules
  • Verifies security configurations

Snapshot Tests (mdaa-installer.snapshot.test.ts)

  • Captures the complete CloudFormation template structure
  • Provides regression testing for template changes
  • Breaks down snapshots by resource types and sections
  • Includes different configuration scenarios

Check environment readiness

cd installer
npm install

Running Tests

All Tests

npm test

Unit Tests Only

npm run test:unit

Snapshot Tests Only

npm run test:snapshot

Update Snapshots

npm run test:snapshot:update

Snapshot Management

When to Update Snapshots

  • After intentional changes to the CloudFormation template
  • When adding new resources or modifying existing ones
  • After updating CDK versions that might change template structure

Reviewing Snapshot Changes

  1. Run tests to see which snapshots have changed
  2. Review the diff to ensure changes are expected
  3. Update snapshots if changes are intentional
  4. Commit both code changes and updated snapshots

Snapshot Files Location

Snapshots are stored in __snapshots__/ directory and should be committed to version control.

Test Categories

Security Tests

  • KMS key rotation
  • S3 bucket encryption
  • SSL enforcement
  • Public access blocks
  • IAM role configurations

Infrastructure Tests

  • CodeBuild project configuration
  • CodePipeline setup (GitHub and S3)
  • S3 bucket policies
  • Resource dependencies

Configuration Tests

  • Parameter validation
  • Conditional resource creation
  • CloudFormation interface metadata
  • Environment variables

Template Structure Tests

  • Complete template snapshots
  • Section-specific snapshots (Parameters, Resources, etc.)
  • Resource type groupings

Best Practices

  1. Run tests before committing: Always run the full test suite before pushing changes
  2. Review snapshot diffs: Carefully review any snapshot changes to ensure they're intentional
  3. Keep tests focused: Each test should verify a specific aspect of the stack
  4. Use descriptive test names: Test names should clearly indicate what is being tested
  5. Update documentation: Keep this README updated when adding new test categories

Troubleshooting

Common Issues

Snapshot Mismatch

Error: expect(received).toMatchSnapshot()
Solution: Review the changes and update snapshots if they're intentional using npm run test:snapshot:update

Test Timeout

Error: Timeout - Async callback was not invoked within the 5000ms timeout
Solution: The Jest configuration includes a 30-second timeout for CDK synthesis. If tests still timeout, check for infinite loops or resource dependency issues.

Missing Dependencies

Error: Cannot find module '@aws-cdk-lib/assertions'
Solution: Ensure all dependencies are installed with npm install

Debug Mode

To run tests with verbose output: 

npm run test:snapshot -- --verbose

Contributing

When adding new tests: 1. Follow the existing naming conventions 2. Group related tests in describe blocks 3. Add appropriate snapshots for new functionality 4. Update this README if adding new test categories 5. Ensure tests are deterministic and don't rely on external state