.flat() is not supported by all browsers

[ashjtan]

Description

The use of the .flat() function is not supported by all browsers (see documentation) and is resulting in a multitude of Sentry errors (1, 2, 3, 4).

Solution

A custom .flat() function like those suggested in this stackoverflow question may help prevent errors caused by outdated browser versions.

That being said, the versions are pretty old, e.g. Google Chrome v68.0 (last incompatible version) was released in July 2018, so patching it up for this may be kind of overkill.