Function randomMutation

packages/core/src/tests/utils.ts:459–497

(o: T)

}

export function randomMutation<T>(o: T): void {
  if (o == null || typeof o !== 'object') {
    return;
  }

  if (Array.isArray(o)) {
    o.forEach(v => randomMutation(v));
    switch (randomNumber(0, 4)) {
      case 0:
        o.splice(randomNumber(0, o.length), randomNumber(0, o.length), randomValue(1));
        break;
      case 1:
        o[randomNumOrStr()] = randomValue(1);
        break;
      case 2:
        o.length ? o.pop() : o.push(randomValue(1));
        break;
      case 3:
        o.length ? o.shift() : o.push(randomValue(1));
        break;
      case 4:
        if (o.length) {
          delete o[selectRandom(Object.keys(o))];
        } else {
          o.push(randomValue(1));
        }
    }
  } else if (isDict(o)) {
    const keys = Object.keys(o);

    keys.forEach(k => randomMutation(o[k]));

    if (!keys.length || randomBoolean()) {
      o[randomNumOrStr()] = randomValue(1);
    } else {
      delete o[selectRandom(keys)];
    }
  }
}

export function safeStringify(
  o: any,