transpiling esm dependencies with ts-node

[talentlessguy]

I'm writing tests for my balance-crypto library and I'm trying to make uvu, ts and ts-node work together.

Is there a good way to transpile dependencies of a library during running ts-node?

atm i get this error because of an ES dependency:

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /home/v1rtl/Coding/money-in-my-wallet/node_modules/.pnpm/github.com+talentlessguy+stablecoin-api@4d066bc1a09abb4ac7b3585eb47da24a8ae37b5c/node_modules/stablecoin-api/index.js
require() of ES modules is not supported.
require() of /home/v1rtl/Coding/money-in-my-wallet/node_modules/.pnpm/github.com+talentlessguy+stablecoin-api@4d066bc1a09abb4ac7b3585eb47da24a8ae37b5c/node_modules/stablecoin-api/index.js from /home/v1rtl/Coding/money-in-my-wallet/src/services/stablecoin.ts is an ES module file as it is a .js file whose nearest parent package.json contains "type": "mod

files

my tsconfig:

{
  "include": ["src", "./example.ts"],
  "compilerOptions": {
    "module": "ESNext",
    "target": "ES2019",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "isolatedModules": true,
    "noEmit": true,
    "lib": ["ES2019"],
    "preserveSymlinks": true
  },
  "ts-node": {
    "transpileOnly": true,
    "compilerOptions": {
      "module": "commonjs"
    },
    "include": ["test/**/*"],
    "exclude": ["node_modules"]
  }
}

test suite:

import { suite } from 'uvu'
import assert from 'uvu/assert'
import { balance } from '../src/index'

const t = suite('blockcypher')

t('should reject invalid address', async () => {
  try {
    await balance('invalid', 'BTC')
  } catch (e) {
    assert.equal(e.message, 'Invalid address "invalid" for BTC')
    assert.instance(e, Error)
  }
})

t('should support BTC, LTC, DASH and DOGE addresses', async () => {
  const balances = [
    {
      coin: 'BTC',
      address: '3PxedDftWBXujWtr7TbWQSiYTsZJoMD8K5'
    },
    {
      coin: 'LTC',
      address: 'MBk5YpWiqWmWC1EVY28qfoKygGQwX343Uu'
    },
    {
      coin: 'DASH',
      address: 'XnTVbwYQdkQNa3ZRsyAA4y1fgMAtmEgb61'
    },
    {
      coin: 'DOGE',
      address: 'DBXu2kgc3xtvCUWFcxFE3r9hEYgmuaaCyD'
    }
  ]

  for (const b of balances) {
    const result = await balance(b.address, b.coin)

    assert.is.not(result?.balance, null)

    assert.is(result?.asset, b.coin)
  }
})

t.run()

[talentlessguy]

the best solution would be not transpiling anything at all and relying only on native esm

if it possible that way anyone who knows please share how

[cspotcode]

Sounds like it's not an issue with your dependencies, it's an issue with your code? You have your tsconfig set to transform your code's imports into require() calls, but you can't require() an ESM module.

Our ESM loader is documented in #1007 and sounds like what you want here.

[talentlessguy]

@cspotcode oh oops I should have read the issue description more carefully

thanks for help!

[talentlessguy]

This is how I made it work:

node --loader ts-node/esm --experimental-specifier-resolution=node node_modules/uvu/bin.js