References vs values in function parameters in JS

ref-value-test.js

const assert = require("assert");

// When we change the contents of an object, we can see
// the change outside the function.
function f1(obj) {
  obj.a += 1;
  assert.deepStrictEqual(obj, { a: 2 });
}
const obj1 = { a: 1 };
f1(obj1);
assert.deepStrictEqual(obj1, { a: 2 });

// But when we destructure an object, we can NOT see the change
// outside the function.
function f2({ a }) {
  a += 1;
  assert.strictEqual(a, 2);
}
const obj2 = { a: 1 };
f2(obj2);
assert.deepStrictEqual(obj2, { a: 1 });

// This is because destructuring is requivalent to
// declaring a new variable and assigning the value of the
// property to it.
function f3(obj) {
  let a = obj.a;
  a += 1;
  assert.strictEqual(a, 2);
}
const obj3 = { a: 1 };
f3(obj3);
assert.deepStrictEqual(obj3, { a: 1 });