def...rescue...ensure...end returns value from ensure block only if explicit directive to do so is present

def-rescue-ensure-end-1.rb

def abc(bool)
  a=b=0
  a+=10
  raise StandardError if bool
  "returning from main func a#{a} b#{b}" # returned unless bool
rescue
  "returning from rescue a#{a} b#{b}" # returned if bool
ensure
  b+=10 # always executed
  puts "printing from ensure a#{a} b#{b}" # always executed
  "returning from ensure a#{a} b#{b}" # never returned
end

abc false
# printing from ensure a10 b10
#=> "returning from main func a10 b0"

abc true
# printing from ensure a10 b10
#=> "returning from rescue a10 b0"

def-rescue-ensure-end-2.rb

def abc(bool)
  a=b=0
  a+=10
  raise StandardError if bool;
  "returning from main func a#{a} b#{b}" # never returned
rescue
  "returning from rescue a#{a} b#{b}" # never returned
ensure
  b+=10 # always executed
  puts "printing from ensure a#{a} b#{b}" # always executed
  # Using an explicit return statement in the ensure block
  return "returning from ensure a#{a} b#{b}" # always returned
end

abc false
# printing from ensure a10 b10
#=> "returning from ensure a10 b10"

abc true
# printing from ensure a10 b10
#=> "returning from ensure a10 b10"