Are immutable globalThis variables possible in JS?

Question

Is there a way to make

globalThis.variable = value

const, final, readonly...?

It would make sense to have global cross-modules variables that are readonly. Of course manually exporting variables makes them immutable in other modules, but it's not the same luxury as just having global variables (that I can just call anywhere, without having to import everywhere).

Answer 1

You can use defineProperty with writable: false:

Object.defineProperty(globalThis, 'variable', {
  value,
  writable: false,
});

Examples:

Silently ignores without "use strict";

Object.defineProperty(globalThis, 'variable', {
  value: 123,
  writable: false,
});

console.log(variable);
variable = 567;
console.log(variable);

Error with "use strict";

"use strict";

Object.defineProperty(globalThis, 'variable', {
  value: 123,
  writable: false,
});

console.log(variable);
variable = 567;
console.log(variable);