[Feature]: setup-jest as function instead of import with side effect

[StavNoyAkur8]

🚀 Feature Proposal

In the current setup, we import the setup file, and it executes as a side effect:

// <root>/test-setup.ts
import "jest-preset-angular/setup-jest";

I would like instead to be able to import it as a function:

import { setupJest } from "jest-preset-angular/setup-jest";

setupJest();

Motivation

Importing as a side effect is non obvious.
Many formatters will automatically put import statements at the top of the document. This makes it so that if we want to setup the global ngJest, which should be before the import, so it's accessible to the setup:

globalThis.ngJest = {
  testEnvironmentOptions:  {
    errorOnUnknownElements: true,
    errorOnUnknownProperties: true,
  };
};
import "jest-preset-angular/setup-jest";

After formatting it goes under the import:

import "jest-preset-angular/setup-jest";

globalThis.ngJest = ...

Rendering it effectively useless.

By having it as a function, we can circumvents that problem by calling it when we're ready:

import { setupJest } from "jest-preset-angular/setup-jest";

globalThis.ngJest = ...
setupJest();

Additionally, it opens the possibility to pass that config as a parameter, instead of having to set the (untyped) global:

setupJest({
  testEnvironmentOptions:  ...
});

Currently, my other workaround is to set the globals in the jest config (which is maybe a better option anyway)

Example

No response

[ahnpnl]

Oh ya I was playing around with this, which is related to this #354 (comment)