Problem Statement

The Data Driven Forms monorepo currently uses an ad-hoc Jest configuration that is not properly structured for NX workspaces. To successfully migrate to TypeScript (Epic RHCLOUD-44570), we need to modernize the Jest test infrastructure to provide reliable test coverage validation throughout the migration process.

Current State

• Complex, non-standard Jest configuration that doesn't follow NX workspace patterns
• Jest v27 with limited TypeScript support
• Inconsistent test environments causing timezone and DOM-related failures
• Test API compatibility issues with updated testing libraries
• No centralized test configuration across packages

Requirements

Jest Configuration Modernization

• Migrate to NX workspace Jest patterns using getJestProjectsAsync() for package auto-discovery
• Create centralized jest.preset.js extending @nx/jest/preset for consistent configuration
• Add individual Jest configuration files for each package following NX best practices
• Remove ad-hoc Jest configuration and test scripts from individual package.json files

TypeScript Integration Setup

• Update Jest to v29 for better TypeScript support
• Integrate ts-jest for proper TypeScript compilation during testing
• Create tsconfig.spec.json for test-specific TypeScript configuration
• Ensure Jest can handle both JavaScript and TypeScript files during migration transition

Test Environment Consistency

• Fix JSDOM setup for reliable React component testing
• Update testing libraries (@testing-library/react, @testing-library/user-event) for compatibility
• Configure consistent UTC timezone to eliminate environment-specific date/time test failures
• Resolve DOM globals and browser API mocking

Test API Compatibility

• Address breaking changes in @testing-library/user-event API (v13+ compatibility)
• Fix keyboard modifier handling in tests (Ctrl+click, Shift+click interactions)
• Resolve timing issues in conditional field value setting tests
• Ensure all existing tests pass without modifying expected behavior or test data

Acceptance Criteria

• All test suites must pass across all component mapper packages:
  • @data-driven-forms/react-form-renderer
  • @data-driven-forms/carbon-component-mapper
  • @data-driven-forms/mui-component-mapper
  • @data-driven-forms/blueprint-component-mapper
  • @data-driven-forms/pf4-component-mapper
  • @data-driven-forms/ant-component-mapper
  • @data-driven-forms/common
• Jest configuration follows NX workspace best practices
• TypeScript compilation and type checking work in test environment
• Consistent test environment eliminates flaky timezone/environment-dependent tests
• No regressions in existing test coverage or functionality
• Test infrastructure supports seamless TypeScript migration process

Technical Approach

File Structure Target

├── jest.config.js              # Root configuration using getJestProjectsAsync()
├── jest.preset.js              # Centralized preset for all packages
├── config/
│   ├── jest.setup.js          # Global test setup
│   └── globalSetup.js         # Global Jest setup (timezone, etc.)
├── tsconfig.spec.json         # TypeScript config for tests
└── packages/
    └── */jest.config.ts       # Individual package configurations

Key Configuration Features Needed

• NX workspace integration with build system and caching
• TypeScript support with full compilation and type checking
• Consistent environment (UTC timezone, JSDOM setup, React testing utilities)
• Proper module mapping for local packages and assets
• Centralized coverage reporting across all packages