[receiver/webhookevent] Allow split at JSON boundary regardless of newline

[mterhar]

Component(s)

No response

Is your feature request related to a problem? Please describe.

Some webhooks send multiple json objects without newlines separating them.

Newline separation issue: #38037

Describe the solution you'd like

Add an option to split based on the pattern where one json object closes } and another begins { which should never happen within an object. Optional whitespace between would still show an object hand-off.

Describe alternatives you've considered

More advanced parsers are available but regex appears sufficient.
As with the new-line splitter, these changes can't be made after the receiver since the number of events that come from the receiver is what we need to change.

Additional context

No response

[github-actions]

Pinging code owners:

• receiver/webhookevent: @atoulme @shalper2

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[axw]

Sounds reasonable. Do you have examples of such webhooks?

Would they produce only concatenated JSON? If so, perhaps an option that tells the receiver to expect that, rather than regex, would be in order. Then you could use an encoding/json.Decoder to decode into a json.RawMessage in a loop until EOF.

[shalper2]

39768 fixed this but the PR was (apparently) abandoned.