loader.js

import { registerHooks } from 'node:module'
import { existsSync } from 'node:fs'
import { spawnSync } from 'node:child_process'
import { resolve } from 'node:path'

const tscPath = resolve(import.meta.dirname, 'node_modules', '@typescript', 'native-preview', 'bin', 'tsgo.js')

const myArgs = process.argv
const packageJSON = resolve(process.cwd(), 'package.json')
const tsconfigJSON = resolve(process.cwd(), 'tsconfig.json')

if ( myArgs.find(a => a.endsWith('.ts')) === undefined ) {
    console.error("Error: must provide a ts file")
    process.exit(1)
}

if (!existsSync(packageJSON) || !existsSync(tsconfigJSON)) {
    console.error("Error: run tsnode --init")
    process.exit(1)
}

let firstScript = true

registerHooks({
    load(url, context, nextLoad) {
        if (firstScript) {
            const { status: tscStatus } = spawnSync('node', [tscPath], {
                stdio: ['inherit', process.stderr, 'inherit']
            })

            if (tscStatus !== 0) {
                const output = nextLoad(url, context)
                output.source = Buffer.from('process.exit(1)')
                return output
            }

            firstScript = false
        }

        return nextLoad(url, context)
    },
})