Helios Webpack loader

This Webpack loader allows importing Helios scripts directly into Javascript/Typescript projects.

Features:

• Helios compilation is run during build time
• Working with Helios sources directly allows using Helios IDE plugins
• Automatically uses your current version of Helios (must be installed manually inside the repo where you configure webpack)
• WiP: generates Typescript declarations for user-defined Helios types (Typescript declaration files are emitted inside the source directory)

Note: the Helios import syntax must use relative paths as literal strings insteads of module names.

Example

A Helios module:

// common.hl
module common

struct Datum {
    secret: Int
}

struct Redeemer {
    guess: Int
}

A Helios validator:

// contract.hl
spending contract 

import { Datum, Redeemer } from "./common.hl"

func main(datum: Datum, redeemer: Redeemer, _) -> Bool {
    datum.secret == redeemer.guess
}

Typescript off-chain code:

// index.ts
import Program from "./contract.hl"

const program = new Program()

const uplcProgram = program.compile(true)

...

The imported Program has the same methods as helios.Program.

Installation and configuration

Install the loader:

npm install --save-dev @hyperionbt/helios-loader

If npm gives the unable to resolve dependency tree error, you can try running the following command to force npm to use your currently installed Helios version:

npm install --save-dev @hyperionbt/helios-loader --legacy-peer-deps

Configure Webpack:

// webpack.config.js
module.exports = {
	mode: "development",
	entry: "./index.ts",
	output: {
		path: __dirname + "/dist/"
	},
	module: {
		rules: [
		  	{
				test: /(?<!\.d)\.(ts|tsx)$/,
				exclude: /node_modules/,
				resolve: {
			  		extensions: [".ts", ".tsx"],
				},
				use: [
					"ts-loader",
					"@hyperionbt/helios-loader" // helios-loader AFTER ts-loader so it is able to modify .ts sources importing Helios scripts BEFORE ts-loader is called
				]
		  	},
			{
				test: /\.(hl|helios)$/,
				exclude: /node_modules/,
				use: [
					{
						loader: "@hyperionbt/helios-loader",
						options: {
							emitTypes: true // must be true when importing Helios scripts in Typescript
						}
					}
				]
			}
		]
	}
}