errors.js

import { createBrowserHistory } from 'history';
const history = createBrowserHistory();

// ERRORS
const notAFunctionError = () => {
  const someArray = [{ func: function () {} }];
  someArray[1].func();
};
const referenceError = () => {
  throw new ReferenceError('undefinedVariable is not defined');
};
//eslint-disable-next-line
const syntaxError = () => eval('foo bar');
const rangeError = () => {
  throw new RangeError('Parameter must be between 1 and 100');
};
const unhandledError = () => {
  throw new UnhandledException('unhandled error');
};

const randomErrors = [
  notAFunctionError,
  referenceError,
  syntaxError,
  rangeError,
  unhandledError,
];

const throwErrorNumber = (i) => {
  randomErrors[i % randomErrors.length]();
};

// if n is 0.2 then this will return false 20% of the time
var probability = function (n) {
  return !!n && Math.random() <= n;
};

const crasher = () => {
  const queryParams = new URLSearchParams(history.location.search);
  if (queryParams !== '') {
    const crash = queryParams.get('crash');
    if (crash) {
      console.log('> crash', crash);
      const errnum =
        queryParams.get('errnum') ||
        parseInt(Math.random() * randomErrors.length);
      if (crash === 'true' || probability(parseFloat(crash))) {
        throwErrorNumber(errnum);
      }
    }
  } else {
    console.log('> queryParam was', queryParams);
  }
};

// Useful for fingerprinting examples and R&D. You can check `if (exception instanceof UnhandledException)`
// Based on the official example https://docs.sentry.io/platforms/javascript/usage/sdk-fingerprinting/#group-errors-with-greater-granularity
class UnhandledException extends Error {
  constructor(message, functionName) {
    super(message);
  }
}

export { crasher, UnhandledException };