Audit and then document chrome-finder paths

[connorjclark]

This is how it works today:

Manually provided chrome location:

• CHROME_PATH / LIGHTHOUSE_CHROMIUM_PATH

• (mac) Any Chrome you've ever opened (uses lsregister)
  Note: this finds lots of installations! https://gist.github.com/connorjclark/97fef0c9a209b4bd09c87f4125a9b678

(linux) Look for any installation in these desktop folders (recursively), adding all found:

• ~/.local/share/applications/
• /usr/share/applications/

(windows) Look for installations:

1. Google/Chrome SxS/Application/chrome.exe
2. Google/Chrome/Application/chrome.exe

in these folders:

• process.env.LOCALAPPDATA
• process.env.PROGRAMFILES
• process.env['PROGRAMFILES(X86)']

Note: the order is: first folder;Chrome SxS;Chrome;second folder; ...

• (linux) which for:
  google-chrome-stable
  google-chrome
  chromium-browser
  chromium

(linux) Do a sorting pass. Because previous steps searched a folder, they need to be sorted by our preference:

• (the manually provided location comes first)
• chrome-wrapper
• google-chrome-stable
• google-chrome
• chromium-browser
• chromium

(mac) Do a sorting pass. Unlike linux, this sorts primarily by installation folder:

• ~/Applications/.*Chrome.app
• ~/Applications/.*Chrome Canary.app
• /Applications/.*Chrome.app
• /Applications/.*Chrome Canary.app
• /Volumes/.*Chrome.app/
• /Volumes/.*Chrome Canary.app/

Note: there is a "fast mac" path. Looks like for mac, we always just do:

• CHROME_PATH
• LIGHTHOUSE_CHROMIUM_PATH
• /Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary
• /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

The full search treatment for mac only happens for getInstallations, which is not called by our launcher.

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Some things we could change:

• getFirstInstallation does the fast mac path, but does not fall back to slow path if none found
• We could provide a similar fast path for each OS
• for lsregister usage, check for duplicates before reading filesystem (minor perf improvement)
• which -a (unix) and where (windows) exist for finding all things on PATH
• drop LIGHTHOUSE_CHROMIUM_PATH (it is deprecated)
• Some of the sorting seems inconsistent

Worth noting that in practice, only the first installation ever matters, but I can imagine that finding all installations on a machine is a useful feature to someone so let's keep it.