Invalid TypeScript declaration files (.d.ts) emitted when mono-repo modules are being referred.

[SayBGM]

🐛 bug report

It seems Parcel fails to emit valid TypeScript declaration files (.d.ts) when the input source is importing any of its mono-repo related modules.

https://github.com/Mint-SayBGM/parcel-typescript-interface-error

🎛 Configuration (.babelrc, package.json, cli command)

package.json

{
  "name": "root",
  "private": true,
  "devDependencies": {
    "@babel/core": "^7.16.0",
    "@babel/preset-env": "^7.16.0",
    "@parcel/packager-ts": "^2.0.1",
    "@parcel/transformer-typescript-types": "^2.0.1",
    "@parcel/config-default": "^2.0.1",
    "@parcel/transformer-typescript-tsc": "^2.0.1",
    "@swc/helpers": "^0.2.13",
    "@typescript-eslint/eslint-plugin": "^5.1.0",
    "@typescript-eslint/parser": "^5.1.0",
    "eslint": "^7.11.0",
    "eslint-plugin-react": "^7.26.1",
    "lerna": "^4.0.0",
    "parcel": "^2.0.1",
    "typescript": "^4.4.4"
  },
  "scripts": {
    "prepare": "lerna run prepare",
    "dev": "lerna run dev --stream",
    "build": "yarn & lerna run build --stream",
    "bootstrap": "lerna bootstrap --use-workspaces"
  },
  "workspaces": [
    "packages/*"
  ]
}

packages/sdk/package.json

{
  "name": "@modules/sdk",
  "version": "0.0.1",
  "license": "ISC",
  "baseUrl": "./src",
  "types": "dist/index.d.ts",
  "main": "dist/index.js",
  "targets": {
    "main": {
      "optimize": true
    }
  },
  "scripts": {
    "prepublishOnly": "yarn build",
    "dev": "yarn build",
    "build": "yarn parcel build src/index.ts",
    "start": "yarn parcel src/index.ts"
  }
}

packages/types/package.json

{
  "name": "@modules/types",
  "version": "1.0.0",
  "private": true,
  "description": "> TODO: description",
  "homepage": "",
  "license": "ISC",
  "types": "dist/index.d.ts",
  "main": "dist/index.js",
  "scripts": {
    "prepare": "yarn build",
    "build": "yarn parcel build index.ts"
  }
}

🤔 Expected Behavior

packages/sdk/dist/index.d.ts

import { AddressItem } from "@modules/types";
export const getZoneCode: (address: AddressItem) => Promise<string>;

//# sourceMappingURL=index.d.ts.map

😯 Current Behavior

packages/sdk/dist/index.d.ts

import { AddressItem as  } from "@modules/types";
export const getZoneCode: (address: AddressItem) => Promise<string>;

//# sourceMappingURL=index.d.ts.map

💁 Possible Solution

Note that I could not reproduce this behavior with TSC so seems like it’s somewhat relates to Parcel’s own build pipeline.

💻 Code Sample

https://github.com/Mint-SayBGM/parcel-typescript-interface-error

🌍 Your Environment

Software	Version(s)
Parcel	^2.0.1
Node	v14.18.2
npm/Yarn	yarn v1.22.17
Operating System	Mac BigSur (11.4)
typescript	^4.4.4

[benpigchu]

Maybe this is a duplicate of #7325 ?

[astegmaier]

I think that #7426 might fix this. However, in the repro steps above, show typescript ^4.4.4 as the dependency (which is somewhat ambiguous, because npm/yarn might install a higher version). @Mint-SayBGM - can you confirm the exact version of typescript that is installed when you get the repro? And see if downgrading to version 4.4.x or earlier fixes the problem?

[benpigchu]

@astegmaier In the yarn.lock from the code sample repo:

https://github.com/Mint-SayBGM/parcel-typescript-interface-error/blob/2c02afa69f121976c0a16fcddabe6107a3f63dd9/yarn.lock#L8616-L8619

The actual installed version of typescript should be 4.5.2

[SayBGM]

I confirmed that downgrading the typescript version solved it.

Thanks so much! @benpigchu