test: parallel/test-dns-setserver-when-querying is sensitive to network conditions

[joyeecheung]

• Version: master
• Platform: macOS Mojave 10.14
• Subsystem: test

I have been observing timeout failure of parallel/test-dns-setserver-when-querying quite frequently lately - this seems to be sensitive to network conditions somehow.

# Behind Chinese GFW
> time out/Release/node /Users/joyee/projects/node/test/parallel/test-dns-setserver-when-querying.js
out/Release/node
0.07s user 0.02s system 1% cpu 6.032 total

# After bypassing Chinese GFW
> time out/Release/node /Users/joyee/projects/node/test/parallel/test-dns-setserver-when-querying.js
out/Release/node
0.07s user 0.02s system 38% cpu 0.226 total

From a glance I couldn't tell if this test is actually sending any network requests but from my observation I think it may need to be moved to test/internet?

(Note: this test is using the Google DNS servers to test dns.setServer - the addresses are constant targets of the Chinese GFW)

[Trott]

Maybe just change goog to [ '127.0.0.1' ] (and rename it to localhost)? Test would still seem to be valid in that situation.

PR to do exactly that: #25694

[Trott]

Fixed in 6d937c0, I believe. (Re-open if I'm wrong, of course!)