Issue with TS4.9 - 'AbortSignal' was also declared here.

[jogibear9988]

Bug Report

After upgradeing to Typescript 4.9 I get now this error.

  [20:27:02] Starting compilation in watch mode...
  
  node_modules/@types/node/globals.d.ts:72:13 - error TS2403: Subsequent variable declarations must have the same type.  Variable 'AbortSignal' must be of 
  type '{ new (): AbortSignal; prototype: AbortSignal; abort(reason?: any): AbortSignal; timeout(milliseconds: number): AbortSignal; }', but here has type 
  '{ new (): AbortSignal; prototype: AbortSignal; timeout(milliseconds: number): AbortSignal; }'.
  
  72 declare var AbortSignal: {
                 ~~~~~~~~~~~
  
    node_modules/typescript/lib/lib.dom.d.ts:2071:13
      2071 declare var AbortSignal: {
                       ~~~~~~~~~~~
      'AbortSignal' was also declared here.
  
  [20:27:09] Found 1 error. Watching for file changes.

[jogibear9988]

This are the packages in my package.json:

"dependencies": {
  "@node-projects/base-custom-webcomponent": "^0.10.3",
  "construct-style-sheets-polyfill": "^3.1.0"
},
"devDependencies": {
  "@node-projects/lean-he-esm": "^3.3.0",
  "@node-projects/node-html-parser-esm": "^2.4.1",
  "@papyrs/stylo": "^0.0.41",
  "@types/codemirror": "^5.60.5",
  "@types/jquery": "^3.5.14",
  "@types/jquery.fancytree": "0.0.7",
  "ace-builds": "^1.13.1",
  "codemirror": "^6.0.1",
  "esprima-next": "^5.8.4",
  "html2canvas": "*",
  "jest": "^29.3.1",
  "jquery": "^3.6.1",
  "jquery.fancytree": "^2.38.2",
  "monaco-editor": "^0.34.1",
  "ts-jest": "^29.0.3",
  "typescript": "^4.9.3",
  "typescript-lit-html-plugin": "^0.9.0"
},

[benmccann]

I ran into this in my project with AbortController and fixed it by upgrading all my dependencies to the latest versions (sveltejs/kit#7657).

[melink14]

devblogs.microsoft.com/typescript/announcing-typescript-4-9/#correctness-changes

We don’t expect major breaks as a result of DOM and lib.d.ts updates, but there may be some small ones.

Why do you reference node AND dom types?

Wouldn't it be quite natural to reference both if you had a web project with node build scripts?

It looks like the goal is to fix it in the node types DefinitelyTyped/DefinitelyTyped#60868 but not sure how long that will take...

[jakebailey]

I'm pretty sure that this is just a case of needing to update types. We fixed this same issue in Monaco a week or so ago by updating deps.

If you don't depend on these directly, try relocking your project.

[melink14]

I agree. I saw there were open related issues so didn't verify but I see there are other closed issues which explicitly updated node types for 4.9. Thanks Jake!

[jogibear9988]

I got this error at first after dooing a "npm-upgrade" (wich upgrades all packages i reference) and then doing a "npm i"

[melink14]

As Jake said, you may have a transitive dependency with out of date node types. In that case try to delete your lock file and then run npm i again. (relock as Jake put it)

[jogibear9988]

I did this. I deleted the lock file.

[jogibear9988]

fixed it by adding @types/node to my dev dependencies

  npm i -d @types/node

[melink14]

That's definitely strange and unexpected but without seeing your setup it's hard to say what went wrong. If you're okay keeping an unused dev dependency, that's probably a solid solution.

[jogibear9988]

You see my setup. Above I posted every Dependecy I have.
The source I used is here: https://github.com/node-projects/web-component-designer

[melink14]

Took a quick look and it was a problem with transitive dependencies, I had not gotten the steps to properly refresh your lockfile correct. You also need to delete node_modules folder. Here's the steps I took in your repo:

1. npx npm-upgrade and say yes to everything.
2. 'npm i`
3. npm run tsc and confirm error.
4. rm package-lock.json
5. rm -Rf node_modules/
6. npm i
7. npm run tsc -> no error!

[jogibear9988]

Thanks
I thought a "npm i" was enough

[fatcerberus]

It used to be that not having lockfiles made dependency management hard. Now deleting the lockfile is a valid troubleshooting method to fix dependency issues. We've come full circle, ladies and gentlemen! 😄

[jogibear9988]

yes, and now you also need to delete node_modules folder... this i found modt discusting