language-tools: VSCode: Formatter slow or freezes if jsconfig.json is present in project

Describe the bug Since updating to 105.4.0 of the VS Code extension the formatter is really slow or freezes when saving a .svelte file making me having to skip formatting from the VS Code prompt almost every time I’m saving a file. There’s a jsconfig.json present in the project, it’s got a couple of aliases mapped in the root of my project.

{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "#js/*": ["./client_src/js/*"],    
      "#api/*": ["./server_src/api/*", "./client_src/js/api/*"],
      "#api/scripts/*": ["./server_src/scripts/api/*"],
      "#api/webapps/*": ["./server_src/webapps/api/*"],
      "#api/restapps/*": ["./server_src/restapps/api/*"],
    }
  },
  "exclude": ["node_modules"]
}

https://code.visualstudio.com/docs/languages/jsconfig

If I remove this file the formatter works as expected.

Version 102.3.0 doesn’t have this problem, I’ve downgraded to that version in the meanwhile.

To Reproduce Add a jsconfig.json file to the project, content doesn’t seem to matter. I added an empty jsconfig.json file, or with an empty object, and this causes the formatter to freeze.

Expected behavior Format the code without freezing.

Screenshots

System (please complete the following information):

OS: Windows 10
IDE: VS Code
Plugin/Package: Svelte for VSCode 102.4.0 102.5.1

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 20 (9 by maintainers)

Most upvoted comments

Closing as there is nothing we can take action on. If performance problems occur, please open a new issue with a detailed reproduction.

dummdidumm on Jun 3, 2021

I guess you have set resolveJsonModule to true in your tsconfig.json? That means to TS “import and analyze that file”, which is slow and not avoidable. If you set resolveJsonModule to false instead and provide a d.ts declaration which tells TS to just assume that any file ending with .json is ok like so:

declare module "*.json" {
  const value: any;
  export default value;
}

Then the file is not analyzed and it should be faster. The disadvantage is that you no longer have type definitions for the JSON module and also TS will not error if there’s no JSON file at the path you specify.

dummdidumm on Jan 13, 2021

I was trying to not open a separate issue unnecessarily, but I think my issue might be different enough that it calls for one. I’ll try to make a minimal repo as well. The project is small.

milky2028 on Nov 19, 2020

I guess most of those files are from the other projects. Because there’s only the jsconfig at the root, everything’s loaded even if not needed. I also think we cannot do much there. The initial load is most likely the TS service reading the config file and then scanning and loading all the js/ts files initially. Since that’s synchronous we are essentially blocked from doing anything else.

dummdidumm on Nov 7, 2020