Base Riot.JS config template with Pug+TypeScript+Stylus precompilers. Use `stylus = require('stylus')` if you use it outside any Gulp environment. It was just the my case, and I want to keep it like it is.

riot.config.js

const { registerPreprocessor } = require('@riotjs/compiler'),
pug = require('pug'),
ts  = require('typescript'),
stylus = require('gulp-stylus').stylus;

registerPreprocessor('template', 'pug', function(code, { options }) {
	const { file } = options

	console.log('Compile the Pug code in', file)

	return {
		code: pug.render(code, {
			filename: file,
			pretty: true,
			doctype: 'html'
		})
	}
})

registerPreprocessor('css', 'stylus', function(code, { options }) {
	const { file } = options
	
	console.log('Compile the Stylus code in', file)
	
	const css = stylus.render(code);
	
	return {
		code: css.toString(),
		map: null
	}
})

// registerPreprocessor('css', 'sass', function(code, { options }) {
// 	const { file } = options

// 	console.log('Compile the sass code in', file)

// 	const {css} = sass.renderSync({
// 		data: code
// 	})

// 	return {
// 		code: css.toString(),
// 		map: null
// 	}
// })


registerPreprocessor('javascript', 'ts', function(code, { options }) {
	const { file } = options

	console.log('Compile the TypeScript code in', file)

	const result = ts.transpileModule(code, {
		fileName: file,
		compilerOptions: {
			module: ts.ModuleKind.ESNext
		}
	})

	return {
		code: result.outputText,
		map: null
	}
})

module.exports = {
	hot: false, // set it to true if you are using hmr
	// add here all the other @riotjs/compiler options riot.js.org/compiler
	javascipt: 'ts',
	template: 'pug',
	css: 'stylus'
}