network-audit is terminated before logs finish writing

Description

While investigating parsing errors for network-audit and during code review w/ @bridiver (for a band-aid patch I had), it became clear that we need to wait until the logs are written out in their entirety to ensure integrity of the network-audit

SIGTERM / SIGKILL were added with https://github.com/brave/brave-browser/pull/4036 which may have introduced the problem. Because the stream for the logger isn’t flushed, there are missing line endings. The first band-aid patch was done for this with https://github.com/brave/brave-browser/pull/2787

Steps to Reproduce

1. Run npm run network-audit on the platform of your choice
2. Open network_log.json in a text editor

Actual result:

Notice how this is likely not proper JSON. It’s missing the ] to close events: [ and then the closing } tag for the entire JSON blob (possibly missing more).

Expected result:

Log should be valid JSON; no “hack” should be needed to parse the file. There might be missing entries- the process needs to complete the log on its own.

[rebron]

cc: @mariospr

[bsclifton]

@diracdeltas that’s definitely one approach; another which @bridiver proposed would be to create a new test suite, something like npm run test brave_network_audit which could wait a predetermined amount of time (or possibly run navigation tests) and then logs would be checked as a final part of the test