implement host redirection via in-app VPN or socket-filter

[kfix]

build some VPN support in for doing ad-hoc redirection/filtering of specific hosts' WebView requests and/or their DNS resolutions
https://github.com/lshuzhi/SimpleTunnelMacos
https://github.com/liruqi/Mume-iOS
https://developer.apple.com/reference/networkextension/netunnelprovidermanager

Chrome does this with --host-rules=MAP <src-pattern> <host:port>, EXCLUDE <pattern>
https://github.com/electron/electron/blob/master/docs/api/chrome-command-line-switches.md#--host-rulesrules

[kfix]

a basic socket-redirection approach:
https://lists.apple.com/archives/darwin-kernel/2013/Jul/msg00007.html
https://developer.apple.com/reference/kernel/sf_connect_out_func?language=objc
https://developer.apple.com/library/content/documentation/Darwin/Conceptual/NKEConceptual/socket_nke/socket_nke.html
https://github.com/ludup/hypersocket-osx

hmm, doesn't provide way to isolate to a specific WebKit-utilizing bundle name, could only attach redirector to all WebKit apps: https://stackoverflow.com/questions/35684211/how-to-identify-a-process-in-c-within-a-mac-network-kernel-extension-socket-fil

https://github.com/iadgov/netfil

[johndpope]

I've come across this ticket - because I'm looking for a way to host a website completely offline using a HAR / http archive file.

I think this may parallel the efforts of this ticket - because you could modify the payloads of captured har file and potentially hack things if need be in swift for more granularity.
I built this codebase for another project - but could be cherry picked.
https://github.com/johndpope/HAR-playback-swift

in one line of code you can pass a har file which allows you to swizzle / intercept http requests and modify payload of urls.

related
HTTPArchive/httparchive.org#96

UPDATE
Never mind - I find this which suits my needs.
https://github.com/webrecorder/webrecorderplayer-electron/releases/tag/v1.5.0