ladybird/Libraries/LibJS/Tests/builtins/Array/array-length-setter.js

load("test-common.js");

try {
  var a = [1, 2, 3];

  assert(a.length === 3);
  assert(a[0] === 1);
  assert(a[1] === 2);
  assert(a[2] === 3);

  a.length = 5;
  assert(a.length === 5);
  assert(a[0] === 1);
  assert(a[1] === 2);
  assert(a[2] === 3);
  assert(a[3] === undefined);
  assert(a[4] === undefined);

  a.length = 1;
  assert(a.length === 1);
  assert(a[0] === 1);

  a.length = 0;
  assert(a.length === 0);

  a.length = "42";
  assert(a.length === 42);

  a.length = [];
  assert(a.length === 0);

  a.length = true;
  assert(a.length === 1);

  [undefined, "foo", -1, Infinity, -Infinity, NaN].forEach(value => {
    assertThrowsError(
      () => {
        a.length = value;
      },
      {
        error: RangeError,
        message: "Invalid array length",
      }
    );
    assert(a.length === 1);
  });

  console.log("PASS");
} catch (e) {
  console.log("FAIL: " + e);
}