# Poiesis

A Go tool that transpiles TypeScript to JavaScript using esbuild and executes it with goja, with an extensible builtin system.

## Project Structure

```
reichard.io/poiesis/
├── cmd/
│   └── poiesis/                    # CLI application entry point
│       └── main.go
├── internal/
│   └── runtime/
│       ├── pkg/
│       │   └── builtin/            # Builtin framework (framework only)
│       │       └── builtin.go     # Registration system & type conversion
│       ├── standard/               # Standard builtin implementations
│       │   ├── fetch.go           # HTTP fetch builtin
│       │   └── fetch_test.go      # Tests for fetch
│       ├── runtime.go              # Transpilation & execution
│       └── runtime_test.go         # Runtime tests
```

## Architecture

The project is cleanly separated into three packages:

1. **`internal/runtime/pkg/builtin`** - The framework for registering builtins and type conversion
   - Generic registration with automatic type inference
   - Bidirectional Go ↔ JavaScript type conversion
   - No builtin implementations (pure framework)

2. **`internal/runtime/standard`** - Standard builtin implementations
   - `fetch`, `add`, `greet`
   - Custom type converters for complex types
   - Independent and easily extensible

3. **`internal/runtime`** - Runtime management
   - TypeScript transpilation with esbuild
   - JavaScript execution with goja
   - Automatically imports and registers standard builtins

## Installation & Build

```bash
go build ./cmd/poiesis
```

## Testing

```bash
go test ./...
golangci-lint run
```

## Usage

```bash
poiesis <typescript-file>
```

## Builtin System

The builtin system allows you to easily expose Go functions to TypeScript/JavaScript.

### Adding a Builtin

Just write a Go function and register it:

```go
// Your function
func add(a, b int) int {
    return a + b
}

// Register it
func init() {
    builtin.RegisterBuiltin("add", add)
}
```

That's it! The framework automatically:

- Converts TypeScript values to Go types
- Handles errors (panics as JS errors)
- Generates TypeScript definitions
- Manages the goja integration

### Example

```typescript
// TypeScript code
console.log("5 + 10 =", add(5, 10));

const response = fetch("https://httpbin.org/get");
console.log("OK:", response.ok);
console.log("Status:", response.status);
console.log("Body:", response.text());
```

### Built-in Functions

- `fetch(url, options?)` - HTTP requests
- `add(a, b)` - Simple arithmetic example
- `greet(name)` - String manipulation example

## Dependencies

- `github.com/evanw/esbuild/pkg/api` - TypeScript transpilation
- `github.com/dop251/goja` - JavaScript execution
- `github.com/stretchr/testify/assert` - Test assertions