🚀 Pascal to Java Migration Template

A comprehensive template for migrating Turbo Pascal applications to modern Java using GitHub Copilot Agents and AI-assisted development.

🎯 Overview

This template provides a complete agent-driven workflow for modernizing legacy Turbo Pascal applications into contemporary Java. It uses specialized GitHub Copilot agents for analysis, specification, testing, development, and documentation.

SDD.-.Modernize.720p.1.5x.mp4

🛠️ Quick Start

DevContainer (Recommended)

1. Open in VS Code with Docker installed
2. Click "Reopen in Container" when prompted
3. Run ./welcome.sh for overview

Local Setup

Follow: docs/turbo-pascal-setup.md

📁 Structure

├── .github/
│   ├── agents/              # 🤖 Copilot agent definitions
│   └── instructions/        # Pascal & Java guidelines
├── legacy/source/           # 📜 Original Turbo Pascal code
├── specs/                   # 📋 Generated specifications
│   ├── diagrams/           # Mermaid diagrams
│   ├── docs/               # Analysis & architecture
│   ├── plans/              # Test & development plans
│   └── tests/              # Test data
├── src/                     # ☕ Java implementation
└── scripts/                 # 🔧 Build utilities

🔧 Development Commands

Pascal:

pascalc filename.pas        # Compile
./filename                  # Run
pascalclean                 # Clean

Java:

mvn compile                 # Build
mvn test                    # Test
mvn package                 # Package

🤖 Agent-Driven Migration Workflow

The migration uses specialized GitHub Copilot agents with flexible planning and implementation paths (see docs/agent-flow.md):

1️⃣ Analyzer Agent

Analyzes Pascal code structure, extracts business logic, identifies dependencies, and generates Mermaid diagrams.

Output: specs/docs/analysis.md, specs/diagrams/code-structure.mmd

2️⃣ Spec Agent

Translates analysis into user stories, architecture specs, and Java design.

Output: specs/docs/user-stories.md, specs/docs/architecture.md, specs/diagrams/architecture.mmd

3️⃣ Test Agent

Designs test strategy, performance benchmarks, and validation criteria.

Output: specs/plans/testplan.md, specs/docs/performance-baseline.md, specs/tests/test-data.json

4️⃣ Planning Phase (Choose One)

• Option 1 - Plan Agent: Custom agent creates development plan
• Option 2 - Plan Mode: VS Code Copilot Chat Plan Mode creates development plan

Output: specs/plans/development-plan.md

5️⃣ Implementation Phase (Choose One)

• Path A - Direct Execution: GitHub Copilot Coding Agent executes plan directly
• Path B - GitHub Issues: Create GitHub Issues for traceability, then assign to GitHub Copilot Coding Agent

Output: Java code, pull requests, (optional) GitHub Issues

6️⃣ Documentation Agent

Maintains Pascal↔Java mapping and migration changelog for traceability.

Output: specs/docs/mapping.md, specs/docs/changelog.md

📚 Documentation

• Agent Flow - Agent collaboration workflow
• Pascal Instructions - Pascal analysis guidelines
• Java Instructions - Java development patterns
• Setup Guide - Manual environment setup

🧪 Testing

• Pascal: Run original programs to document expected behavior
• Java: JUnit 5, AssertJ, Mockito, JaCoCo coverage
• Validation: Side-by-side comparison, performance benchmarks

🔧 Stack

Pascal: Free Pascal Compiler (FPC), Turbo Pascal mode
Java: OpenJDK 17, Maven, JUnit 5, AssertJ, Mockito
Tools: GitHub Copilot, VS Code, Docker

🎯 Migration Patterns

Pascal Procedure → Java Method

procedure ProcessData(var data: TDataArray);

public void processData(List<DataItem> data)

Pascal Record → Java Record

type TEmployee = record
    name: string; age: integer;
end;

public record Employee(String name, int age) {}

🚨 Key Challenges

• Memory: Pascal manual → Java garbage collection
• Strings: Pascal fixed-length → Java immutable objects
• I/O: Pascal text files → Java streams with try-with-resources
• Errors: Pascal goto/codes → Java exceptions

🆘 Troubleshooting

Pascal: Check fpc -h, use -Mtp flag, run ./scripts/verify-pascal-setup.sh
Java: Verify java -version, mvn -version, check mvn dependency:tree
Copilot: Ensure authentication and active subscription

---

Transform legacy Pascal into modern Java with AI-powered agents! 🎉