Sentry v7 - Error in IE11 even after transpiling with babel

[alexgibson]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which package are you using?

@sentry/browser

SDK Version

7.0.0

Framework Version

No response

Link to Sentry event

No response

Steps to Reproduce

1. Upgraded to Sentry 7.0.0
2. Transpiled Sentry bundle from ES6 -> ES5 using Babel (v7.17.9)
3. Loaded a page containing the Sentry JS bundle in Internet Explorer 11

Expected Result

The Sentry JS bundle should load without errors

Actual Result

IE11 throws an error SCRIPT1006: Expected ')'

Looking at the compiled result, it seems like there's a small portion of code that Babel fails to transpile correctly. Notice there are still some const, let variables, as well as some arrow functions that have not been caught.

let l;
(() =>{
  const {
    performance: t
  }
  = (0, r.R) ();
  if (t && t.now) {
    var e = 3600000,
    n = t.now(),
    i = Date.now(),
    s = t.timeOrigin ? Math.abs(t.timeOrigin + n - i) : e,
    o = s < e,
    a = t.timing && t.timing.navigationStart,
    c = 'number' == typeof a ? Math.abs(a + n - i) : e;
    return o || c < e ? s <= c ? (l = 'timeOrigin', t.timeOrigin) : (l = 'navigationStart', a) : (l = 'dateNow', i)
  }
  l = 'none'
}) ()

The rest of the transpiled code looks OK, as far as I can tell.

[AbhiPrasad]

Hey, thanks for writing in! This is strange 🤔. The code that appears to be problematic here is a a IIFE we use in @sentry/utils in time.ts.

We just tested this and couldn't reproduce.

(used https://es6console.com/ + https://unpkg.com/@sentry/utils@7.0.0/esm/time.js )

Could you provide some kind of reproduction, or details about your setup (bundler usage etc.)?

[alexgibson]

Thanks for the quick reply!

Could you provide some kind of reproduction, or details about your setup (bundler usage etc.)?

We're using Webpack / Babel. Here's a link to our package.json for version dependencies: https://github.com/mozilla/bedrock/blob/main/package.json#L6

Here's a link to the PR where I'm testing things out mozilla/bedrock#11706

[alexgibson]

Here's a link to our compiled output: https://www-demo1.allizom.org/media/js/sentry.js

[alexgibson]

After some investigation I believe this is an issue with our project's config, not a Sentry issue. Thanks anyway!