I have library my-lib which is consumed by my-application.

I have updated my-application and my-lib from Angular15 to Angular16.

After that I recognize that There is issue with modules imports for example

Module not found: Error: Can't resolve (name of module) (with relative path)

Example import is

import {MyModuleOne} from 'my-Lib/my-module-one';

If I will change import to below all works fine.

import {MyModuleOne} from 'my-lib'

After some more investigation I also saw that problem is resolved when I will change some configuration in my-lib package.json file from this

{
  "exports": {
    "./*": {
      "types": "./index.d.ts",
      "esm2020": "./esm2020/my-lib.mjs",
      "es2020": "./fesm2020/my-lib.mjs",
      "es2015": "./fesm2015/my-lib.mjs",
      "node": "./fesm2015/my-lib.mjs",
      "default": "./fesm2020/my-lib.mjs"
    }
  }
}

To that one

{
  "exports": {
    "./*": {
      "types": "./index.d.ts",
      "esm2022": "./esm2022/my-lib.mjs",
      "es2022": "./fesm2022/my-lib.mjs",
      "node": "./fesm2022/my-lib.mjs",
      "default": "./fesm2022/my-lib.mjs"
    }
  }
}

My question is why after this change imports like below start working correctly?

import {MyModuleone} from 'my-lib/my-module-one';

I also add that in my dist > my-lib > there were esm2022 and fesm2022 files, so not esm2020, es2020 or es2015 or fesm2015… despite of that changed import was working correctly, how it’s possible?

import {MyModuleone} from 'my-lib';