8bitworkshop/src/ide/errorreport.ts

// Lightweight error reporting to our own server (replaces sentry).
// Sends a GET image beacon to /err.gif - the web server returns 404,
// but the request (with the error in the query string) lands in the
// access log. Grep it with:
//   grep 'err.gif' access.log
// No dependencies, fire-and-forget, safe to call from error handlers.
// NOTE: no server-side rate limiting or log rotation - the web
// server's log rotation handles size; client-side limits below
// prevent flooding.

const MAX_ERRORS_PER_SESSION = 10;

let errorsSent = 0;
let lastMsgSent = '';
let lastMsgTime = 0;

export function reportErrorToServer(msg: string, err?: any) {
  try {
    if (errorsSent >= MAX_ERRORS_PER_SESSION) return;
    // don't repeat the same error more than once per 10 seconds
    const now = Date.now();
    if (msg === lastMsgSent && now - lastMsgTime < 10000) return;
    errorsSent++;
    lastMsgSent = msg;
    lastMsgTime = now;
    var params = {
      msg: (msg + '').substring(0, 300),
      stack: (err && err.stack ? err.stack + '' : '').substring(0, 1000),
      url: window.location.href,
    };
    var qs = Object.keys(params).map((k) => k + '=' + encodeURIComponent(params[k])).join('&');
    var img = new Image();
    img.src = '/err.gif?' + qs;
  } catch (e) {
    // never let error reporting throw
  }
}