polyglot-test-generation

name

polyglot-test-generation

description

Generates comprehensive, workable unit tests for any programming language using a multi-agent pipeline. Use when asked to generate tests, write unit tests, improve test coverage, add test coverage, create test files, or test a codebase. Supports C#, TypeScript, JavaScript, Python, Go, Rust, Java, and more. Orchestrates research, planning, and implementation phases to produce tests that compile, pass, and follow project conventions.

Polyglot Test Generation Skill

An AI-powered skill that generates comprehensive, workable unit tests for any programming language using a coordinated multi-agent pipeline.

When to Use This Skill

Use this skill when you need to:

• Generate unit tests for an entire project or specific files
• Improve test coverage for existing codebases
• Create test files that follow project conventions
• Write tests that actually compile and pass
• Add tests for new features or untested code

How It Works

This skill coordinates multiple specialized agents in a Research → Plan → Implement pipeline:

Pipeline Overview

┌─────────────────────────────────────────────────────────────┐
│                     TEST GENERATOR                          │
│  Coordinates the full pipeline and manages state            │
└─────────────────────┬───────────────────────────────────────┘
                      │
        ┌─────────────┼─────────────┐
        ▼             ▼             ▼
┌───────────┐  ┌───────────┐  ┌───────────────┐
│ RESEARCHER│  │  PLANNER  │  │  IMPLEMENTER  │
│           │  │           │  │               │
│ Analyzes  │  │ Creates   │  │ Writes tests  │
│ codebase  │→ │ phased    │→ │ per phase     │
│           │  │ plan      │  │               │
└───────────┘  └───────────┘  └───────┬───────┘
                                      │
                    ┌─────────┬───────┼───────────┐
                    ▼         ▼       ▼           ▼
              ┌─────────┐ ┌───────┐ ┌───────┐ ┌───────┐
              │ BUILDER │ │TESTER │ │ FIXER │ │LINTER │
              │         │ │       │ │       │ │       │
              │ Compiles│ │ Runs  │ │ Fixes │ │Formats│
              │ code    │ │ tests │ │ errors│ │ code  │
              └─────────┘ └───────┘ └───────┘ └───────┘

Step-by-Step Instructions

Step 1: Determine the user request

Make sure you understand what user is asking and for what scope. When the user does not express strong requirements for test style, coverage goals, or conventions, source the guidelines from unit-test-generation.prompt.md. This prompt provides best practices for discovering conventions, parameterization strategies, coverage goals (aim for 80%), and language-specific patterns.

Step 2: Invoke the Test Generator

Start by calling the test-generator agent with your test generation request:

Generate unit tests for [path or description of what to test], following the [unit-test-generation.prompt.md](unit-test-generation.prompt.md) guidelines

The Test Generator will manage the entire pipeline automatically.

Step 3: Research Phase (Automatic)

The researcher agent analyzes your codebase to understand:

• Language & Framework: Detects C#, TypeScript, Python, Go, Rust, Java, etc.
• Testing Framework: Identifies MSTest, xUnit, Jest, pytest, go test, etc.
• Project Structure: Maps source files, existing tests, and dependencies
• Build Commands: Discovers how to build and test the project

Output: .testagent/research.md

Step 4: Planning Phase (Automatic)

The planner agent creates a structured implementation plan:

• Groups files into logical phases (2-5 phases typical)
• Prioritizes by complexity and dependencies
• Specifies test cases for each file
• Defines success criteria per phase

Output: .testagent/plan.md

Step 5: Implementation Phase (Automatic)

The implementer agent executes each phase sequentially:

1. Read source files to understand the API
2. Write test files following project patterns
3. Build using the builder subagent to verify compilation
4. Test using the tester subagent to verify tests pass
5. Fix using the fixer subagent if errors occur
6. Lint using the linter subagent for code formatting

Each phase completes before the next begins, ensuring incremental progress.

Coverage Types

• Happy path: Valid inputs produce expected outputs
• Edge cases: Empty values, boundaries, special characters
• Error cases: Invalid inputs, null handling, exceptions

State Management

All pipeline state is stored in .testagent/ folder:

File	Purpose
.testagent/research.md	Codebase analysis results
.testagent/plan.md	Phased implementation plan
.testagent/status.md	Progress tracking (optional)

Examples

Example 1: Full Project Testing

Generate unit tests for my Calculator project at C:\src\Calculator

Example 2: Specific File Testing

Generate unit tests for src/services/UserService.ts

Example 3: Targeted Coverage

Add tests for the authentication module with focus on edge cases

Agent Reference

Agent	Purpose	Tools
test-generator	Coordinates pipeline	execute, read, edit, search, agent
researcher	Analyzes codebase	execute, read, edit, search, web, agent
planner	Creates test plan	read, edit, search, agent
implementer	Writes test files	execute, read, edit, search, agent
builder	Compiles code	execute, read, search
tester	Runs tests	execute, read, search
fixer	Fixes errors	execute, read, edit, search
linter	Formats code	execute, read, search

Requirements

• Project must have a build/test system configured
• Testing framework should be installed (or installable)
• VS Code with GitHub Copilot extension