Stack parsers use both `?` and `<anonymous>` to denote anonymous functions

Chrome/v8 stack frames use ? to denote anonymous functions but we also use <anonymous> in a few places.

https://github.com/getsentry/sentry-javascript/blob/78395c6c6f2cf7b9a8afe907c6396d911b83d3b6/packages/utils/src/stacktrace.ts#L75

https://github.com/getsentry/sentry-javascript/blob/78395c6c6f2cf7b9a8afe907c6396d911b83d3b6/packages/utils/src/stacktrace.ts#L80

[kamilogorek]

@kamilogorek any ideas on why this happens?

Historical reasons. It was called <anonymous> (the same value as anonymous URLs/files in some old browsers) since raven SDK, and we kept it like that. ? comes directly from Tracekit, which was also not changed since the old SDK, as the grouping strategy back then did not group them together afair. Changing this would cause some new issues to pop up.

Now, this will not affect any grouping (at least for one version of it), due to those frames being skipped, see: https://github.com/getsentry/sentry/blob/46d9c2aa672b8abe2e26e52c60e9ffc32eba9c23/src/sentry/grouping/strategies/newstyle.py#L394-L398

Also original references: https://github.com/getsentry/sentry-javascript/blob/7b664ff3a828fe59e32ccc182d5b4bb449dc9402/packages/raven-js/src/raven.js#L1122 https://github.com/getsentry/sentry-javascript/blob/7b664ff3a828fe59e32ccc182d5b4bb449dc9402/packages/raven-js/vendor/TraceKit/tracekit.js#L29

[AbhiPrasad]

How about we just backlog for the next major bump then? I don’t mind tabling this patch until then since we treat it identically for grouping strategies.