dspy.ts/logs/phase2.md

DSPy.ts - Declarative Self-Learning TypeScript: A framework for compositional LM pipelines with self-improving prompt strategies.

# Phase 2: Core DSL & Module Infrastructure Implementation Log

## Implementation Date
2/22/2025

## Components Implemented

### 1. Core Types and Interfaces (signature.ts)
- Implemented `FieldDefinition` interface for input/output field definitions
- Implemented `Signature` interface for module signatures
- Added type guard `isValidFieldDefinition` for field validation
- Test Coverage: 100%

### 2. Base Module Class (module.ts)
- Implemented abstract `Module` class with generic input/output types
- Added input/output validation with type checking
- Implemented support for different execution strategies (Predict, ChainOfThought, ReAct)
- Added prompt template handling
- Test Coverage: 95.34%
- Uncovered Lines: 8489 (minor edge cases in validation)

### 3. Pipeline Executor (pipeline.ts)
- Implemented `runPipeline` function for sequential module execution
- Added pipeline configuration options (stopOnError, debug)
- Implemented error handling with configurable behavior
- Added debug logging support
- Test Coverage: 100%

## Test Coverage Summary
- Overall Coverage: 97.1%
- Branch Coverage: 95.34%
- Function Coverage: 100%
- Statement Coverage: 97.1%

## Key Decisions

1. **Module Validation Methods**
   - Initially made validation methods protected
   - Changed to public for better testability
   - Allows modules to call validation directly when needed

2. **Pipeline Error Handling**
   - Implemented configurable error handling with stopOnError option
   - Added error logging for non-stopping errors
   - Ensures pipeline can continue even if individual modules fail

3. **Type Safety**
   - Used TypeScript generics for type-safe module input/output
   - Added runtime type validation to complement static typing
   - Ensures both compile-time and runtime type safety

## Files Created
- src/core/signature.ts
- src/core/module.ts
- src/core/pipeline.ts
- tests/core/signature.spec.ts
- tests/core/module.spec.ts
- tests/core/pipeline.spec.ts

## Commits
1. "Implement core signature types and validation with 100% test coverage"
2. "Implement base Module class with comprehensive tests"
3. "Implement pipeline executor with comprehensive tests"
4. "Export core components from index file"

## Dependencies Added

### 1. ML Dependencies
- Added onnxruntime-web for ONNX model support
- Added js-pytorch for PyTorch model support
- Updated install.sh to include required system dependencies:
  - Added libgl1-mesa-dev for OpenGL support
  - Created separate ML dependencies installation step
- Verified successful installation and compilation

## Next Steps
Ready to proceed with Phase 3: LM Driver & DummyLM implementation