Expect -re not failing on eof - tcl

Question

I have the following expect script.
This is test.exp
#!/usr/bin/expect
# exp_internal 1
# log_file -noappend ~/expect.log
# Use `send_log` to print to log file
set timeout 30
set bold [exec tput bold]
set red [exec tput setaf 1]
set green [exec tput setaf 2]
set normal [exec tput sgr0]
proc test_label {value} {
upvar bold bold
upvar normal normal
puts "Running ${bold}${value}${normal}…"
}
proc test_send {value} {
sleep 0.1
send "$value"
}
proc test_failed {} {
upvar bold bold
upvar red red
upvar normal normal
sleep 0.1
puts "${bold}${red}Failed${normal}"
exit 1
}
proc test_ok {{force_close false}} {
upvar bold bold
upvar green green
upvar normal normal
sleep 0.1
puts "${bold}${green}OK${normal}"
if {$force_close} {
close
}
}
expect_before {
default {
test_failed
}
}
This is electrum.exp
#!/usr/bin/expect
source ./test.exp
test_label "Should create Electrum mnemonic"
spawn qr-backup.sh --create-electrum-mnemonic
expect {
-re {Format USB flash drive \(y or n\)\?} {
test_send "n\r"
}
}
expect {
-re {\[sudo\] password for pi:} {
test_send "$env(password)\r"
}
}
expect {
-re {Creating Electrum mnemonic…}
}
expect {
-re {([a-z]+ ?){24}} {
test_ok true
}
}
Why doesn’t script fail when last line returned by spawn qr-backup.sh --create-electrum-mnemonic is electrum: error: unrecognized arguments: --nbits 264?

Answer 1

Figured it out!
Solved using eof statement.
expect {
-re {([a-z]+ ?){24}} {
test_ok true
}
eof {
test_failed
}
}

Answer 2

Note this from the expect man page:
expect_before [expect_args]
Unless overridden by a -i flag, expect_before patterns match against the spawn id defined at the time that the expect_before command was executed (not when its pattern is matched).
(emphasis mine)
No spawn id was active when the expect_before command was executed.