Add test-drive framework and migrate 18 tests (20% complete)

[parikshitbajpai]

Summary

Implements a modern test-drive based testing framework for Thermochimica and converts 18 tests from the legacy standalone test system.

Test Coverage

Tests Converted: 18 of ~90 (20% complete)
All Tests Status: ✅ PASSING

Error Handling Suite (13 tests - COMPLETE)

• ✅ TestThermo01-13: All input validation and error detection tests
• Tests for: missing files, invalid inputs, out-of-range values, NaN/Inf detection, invalid units

System Validation Suite (5 tests)

• ✅ TestThermo14: Parser stress test (42 solution phases)
• ✅ TestThermo30-33: Multi-element equilibrium calculations
• Tests validate Gibbs energy and mole fractions with 0.1% tolerance

New Infrastructure

Test Framework:

• test/testdrive.F90: Test-drive framework (2,441 lines, from Fortran-lang)
• test/test_main.F90: Main test driver
• test/test_error_handling.F90: Error handling suite (371 lines)
• test/test_systems.F90: System validation suite (240 lines)

Documentation:

• test/README_TEST_DRIVE.md: Complete usage guide and conversion patterns
• test/QUICK_START.md: Quick reference for adding tests
• test/MIGRATION_STATUS.md: Detailed progress tracking
• test/CONVERSION_SUMMARY.md: Session summary

Key Improvements

1. Better Error Reporting: Tests now report actual vs expected values with descriptive messages
2. Organized Suites: Tests grouped logically by functionality (error handling, systems, etc.)
3. Partial Failures: One test failure doesn't stop the entire suite
4. Modern Patterns: Uses Fortran derived types and proper state management
5. State Management: Proper cleanup with ResetThermoAll prevents test interference

Build and Run

# Build and run test-drive tests
make runtests

# Just build
make testdrive

# Build everything (legacy + test-drive)
make test

Test Output

==========================================
  Thermochimica Test Suite (test-drive)
==========================================

# Testing: error_handling (13/13 passing)
# Testing: systems (5/5 passing)

==========================================
SUCCESS: All tests passed!
==========================================

Migration Path

• Phase 1: ✅ Infrastructure and 3 initial tests
• Phase 2: ✅ Complete error handling suite (13 tests)
• Phase 3: 🔄 System validation tests (5/~30 complete)
• Phase 4: 📋 Remaining edge cases and special models
• Estimated completion: ~8-12 hours for remaining 72 tests

Benefits

• Modern Fortran testing framework (actively maintained by Fortran-lang)
• Foundation for CI/CD automation
• Better test organization and maintainability
• Rich error reporting for debugging
• Clear patterns established for future conversions

Backward Compatibility

• Legacy test system remains fully functional
• Both systems run in parallel during migration
• No breaking changes to production code

🤖 Generated with Claude Code