Test case for WTF is up with System Events getting the processes for Safari and WebKit

frontmost-browser.sh

#!/bin/bash

function safari { open -a Safari; }
function webkit { open -a WebKit; }

function reset {
  killall Safari 2>/dev/null
  killall WebKit 2>/dev/null
}

function bring_front {
  osascript -e "tell application \"$1\" to activate"
}

function get_name_of_frontmost_with_assignment {
  echo -n "assigned: "
  osascript -e 'tell application "System Events" to set _app to the first process whose frontmost is true
                get the short name of _app'
}

function get_name_of_frontmost_directly {
  echo -n "directly: "
  osascript -e 'tell application "System Events" to get the short name of the first process whose frontmost is true'
}

echo "### with only safari running"
reset; safari
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

sleep 2
echo "### with only webkit running"
reset; webkit
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

sleep 2
echo "### with both running, safari started first, safari frontmost"
reset; safari; webkit
bring_front Safari
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

echo "### with both running, safari started first, webkit frontmost"
bring_front WebKit
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

sleep 2
echo "### with both running, webkit started first, webkit frontmost"
reset; webkit; safari
bring_front WebKit
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

echo "### with both running, webkit started first, safari frontmost"
bring_front Safari
get_name_of_frontmost_directly
get_name_of_frontmost_with_assignment

reset

Output:

$ ./frontmost-browser.sh
### with only safari running
directly: Safari
assigned: Safari
### with only webkit running
directly: WebKit
assigned: WebKit
### with both running, safari started first, safari frontmost
directly: Safari
assigned: Safari
### with both running, safari started first, webkit frontmost
directly: WebKit
assigned: Safari
### with both running, webkit started first, webkit frontmost
directly: WebKit
assigned: WebKit
### with both running, webkit started first, safari frontmost
directly: Safari
assigned: WebKit

Output reformatted as a pretty table:

+----------------+-----------+----------+----------+
| Launch order   | Frontmost | directly | assigned |
+----------------+-----------+----------+----------+
| Safari         |           | Safari   | Safari   |
| WebKit         |           | WebKit   | WebKit   |
| Safari, WebKit | Safari    | Safari   | Safari   |
| Safari, WebKit | WebKit    | WebKit   | Safari * |
| WebKit, Safari | WebKit    | WebKit   | WebKit   |
| WebKit, Safari | Safari    | Safari   | WebKit * |
+----------------+-----------+----------+----------+

* indicates incorrect results.

This is part of http://stdout.caiochassot.com/post/2969463643/writing-applescripts-that-dynamically-target-either