Here is a code example

export default class Entity {
   #id
   #tag
   #alive = true

   constructor(tag = "default", id = 0) {

       this.#tag = tag
       this.id = id

   }
}

If this code is in a file with a .ts extension I get the following error on the this.id = id , assignment:Property 'id' does not exist on type 'Entity'.ts(2339)
If I turn this file into a .js extension I no longer get this error ONLY if I do not assign it, in my jsconfig.json I have tried the following:

{
    "compilerOptions": {
      "module": "ESNext",
      "target": "ESNext",
      "checkJs": true,
      // Strict Checks
      "strictPropertyInitialization": true,
      "alwaysStrict": true, // Ensures that your files are parsed in the ECMAScript strict mode, and emit “use strict” for each source file.
      "allowUnreachableCode": false, // pick up dead code paths
      "noImplicitAny": true, // In some cases where no type annotations are present, TypeScript will fall back to a type of any for a variable when it cannot infer the type.
      "strictNullChecks": true, // When strictNullChecks is true, null and undefined have their own distinct types and you’ll get a type error if you try to use them where a concrete value is expected.

      // Linter Checks
      "noImplicitReturns": true,
      "noUncheckedIndexedAccess": true, // accessing index must always check for undefined
      "noUnusedLocals": true, // Report errors on unused local variables.
      "noUnusedParameters": true // Report errors on unused parameters in functions
    }
}

I want to achieve the same behavior using a .js as with the .ts