"@parcel/transformer-typescript-types: Got unexpected undefined" on parcel@2.0.0-nightly.554

I saw this issue reported here: https://github.com/parcel-bundler/parcel/issues/4035

But I think this case is different.

This is the full error message:

yarn workspace v1.22.10
yarn run v1.22.10
$ parcel build ./src/index.ts
🚨 Build failed.
@parcel/transformer-typescript-types: Got unexpected undefined
Error: Got unexpected undefined
    at nullthrows (/path-to-project/node_modules/nullthrows/nullthrows.js:7:15)
    at Object.transform (/path-to-project/node_modules/@parcel/transformer-typescript-types/lib/TSTypesTransformer.js:204:42)
    at async runTransformer (/path-to-project/node_modules/@parcel/core/lib/Transformation.js:651:3)
    at async Transformation.runPipeline (/path-to-project/node_modules/@parcel/core/lib/Transformation.js:422:36)
    at async Transformation.runPipelines (/path-to-project/node_modules/@parcel/core/lib/Transformation.js:363:40)
    at async Transformation.run (/path-to-project/node_modules/@parcel/core/lib/Transformation.js:277:19)
    at async Child.handleRequest (/path-to-project/node_modules/@parcel/workers/lib/child.js:255:9)

when I run yarn build.

Here is the relevant part of my package.json

  "type": "module",
  "main": "dist/main/index.js",
  "types": "dist/index.d.ts",
  "scripts": {
    "build": "parcel build ./src/index.ts",
    "dev": "parcel watch ./src/index.ts"
  }

I will add that this was all working 100% less than 24 hours ago. I have the dependency of "parcel": "^2.0.0-beta.1", which is pulling parcel@2.0.0-nightly.554. I cannot confirm whether it was pulling that same version earlier this morning or yesterday, but it looks like that has been the latest release for about three days now, so I am pretty sure that hasn’t changed.

EDIT:

One thing that works is if I turn off types and reference a manually written types declaration:

  "types": "index.d.ts",
  "targets": {
    "types": false
  },

But, it definitely worked without having to do this just this morning and yesterday, so I am not sure how this might be related.

Parcel seems like an awesome project and I really want to use it, so I would appreciate any help with this.

🤔 Expected Behavior

The project builds every time, even without types: false

😯 Current Behavior

The project does not build. This behavior started some time within the last 16 hours or so.

💻 Code Sample

I can try to put together a small project that reproduces the error if need be, although I would first like to see if this issue seems familiar to anyone here and if there are some things that I can try.

🌍 Your Environment

Software	Version(s)
Parcel	parcel@2.0.0-nightly.554
Node	v12.20.1
npm/Yarn	yarn 1.22.10
Operating System	MacOS 10.15.7

[Banou26]

This issue is still present for me.

I get the same exact error(@parcel/transformer-typescript-types: Got unexpected undefined) with a 500 nightly build on Parcel.

But on a 600-700 nightly build, i get those errors instead

@parcel/transformer-typescript-types: Cannot find global value 'Promise'.      

@parcel/transformer-typescript-types: Cannot find module '@mfkn/oz-web/src/api/api' or its corresponding type declarations.

@parcel/transformer-typescript-types: An async function or method in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your '--lib' option.

  C:/dev/oz/lib/src/index.ts:27:38
    26 | if (window.parent !== window) {
  > 27 |   window.addEventListener('message', async ev => {
  >    |                                      ^^^^^^^^^^^^^^ An async function 
or method in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a 
declaration for the 'Promise' constructor or include 'ES2015' in your '--lib' option.
    28 |     const { data: messageData, origin }: { data: ApiMessageData } & Om    29 |

Even though running tsc returns Found 0 errors.

[jeffpeck10x]

So… in the process of making this into a smaller project that reproduces the error, I found several things that needed to be cleaned.

Everything is now working, but I cannot say for sure what exactly “fixed” it, especially since even while having this issue, it seemed to sometimes build even without “fixing” anything.

I even tried reintroducing the things that were “wrong” in the original project (like a .d.ts file that was importing a nonexistent module), but my test project still builds, even after deleting .parcel-cache.

I would still consider this to be a bug, as the problem is ultimately that this error message did not contain any helpful information:

@parcel/transformer-typescript-types: Got unexpected undefined

Still, the fact that I cannot seem to pinpoint what the problem is means that it would be impossible to look into any further.

I think this can be closed, and if this comes up again in some easily repeatable way, I will create a new issue for it.