magic-string-218.js

const MagicString = require('magic-string');
const assert = require('assert');
const kleur = require('kleur');

function test() {
  const s1 = new MagicString('abcde');
  const s2 = s1.clone();

  const desiredResult = 'abxcde';

  // Sanity check without remove call.
  s2.prependRight(2, 'x');
  assert(s2.toString() == desiredResult, `Sanity check failed!`);

  // Prove that current methods are not
  // sufficient for the desired behavior.

  s1.remove(1, 3);
  assert(s1.toString() == 'ade');

  // Restore the removed range with appendLeft.
  s1.appendLeft(1, s1.original.slice(1, 3));
  assert(s1.toString() == 'abcde');

  // But now prependRight behaves differently when
  // compared with the sanity check.
  s1.prependRight(2, 'x');
  assert(s1.toString() == desiredResult, `${s1} !== ${desiredResult}`);
}

try {
  test();
  console.log(kleur.green('All assertions passed!'));
} catch (e) {
  console.error(kleur.red(e.message));
}