Exit Status Model

Command-line programs report success or failure with an exit status code.
exit status Ruby programs can compute a status code before passing it to `exit`; examples can model the value without ending the replay early.
                            example
                            valid = true, warnings = 1 (default)valid = falsewarnings = 0warnings = 3
                        

                            exit_status_model.rb
                        
Replay: real traced execution (multi-file project)

                            valid = true
warnings = 1

status = if !valid
  1
elsif warnings > 0
  2
else
  0
end

meaning = case status
when 0
  "success"
when 1
  "error"
else
  "warning"
end

puts "valid=#{valid}"
puts "warnings=#{warnings}"
puts "status=#{status}"
puts "meaning=#{meaning}"
valid = false
warnings = 1

status = if !valid
  1
elsif warnings > 0
  2
else
  0
end

meaning = case status
when 0
  "success"
when 1
  "error"
else
  "warning"
end

puts "valid=#{valid}"
puts "warnings=#{warnings}"
puts "status=#{status}"
puts "meaning=#{meaning}"
valid = true
warnings = 0

status = if !valid
  1
elsif warnings > 0
  2
else
  0
end

meaning = case status
when 0
  "success"
when 1
  "error"
else
  "warning"
end

puts "valid=#{valid}"
puts "warnings=#{warnings}"
puts "status=#{status}"
puts "meaning=#{meaning}"
valid = true
warnings = 3

status = if !valid
  1
elsif warnings > 0
  2
else
  0
end

meaning = case status
when 0
  "success"
when 1
  "error"
else
  "warning"
end

puts "valid=#{valid}"
puts "warnings=#{warnings}"
puts "status=#{status}"
puts "meaning=#{meaning}"

                        
1valid ← true, warnings ← 1, status ← 2, meaning ← warning1valid→ true = true  #@valid=false2warnings→ 1 = 1  #@warnings=0, 334status→ 2 = if !validtrue5  16elsif warnings1 > 07  28else9  010end1112meaning→ warning = case status213when 014  "success"15when 116  "error"17else18  "warning"19end2021puts "valid=#{validtrue}"22puts "warnings=#{warnings1}"23puts "status=#{status2}"24puts "meaning=#{meaningwarning}"⋯outputvalid=true
warnings=1
status=2
meaning=warning
1valid ← false, warnings ← 1, status ← 1, meaning ← error1valid→ false = false2warnings→ 1 = 134status→ 1 = if !validfalse5  16elsif warnings1 > 07  28else9  010end1112meaning→ error = case status113when 014  "success"15when 116  "error"17else18  "warning"19end2021puts "valid=#{validfalse}"22puts "warnings=#{warnings1}"23puts "status=#{status1}"24puts "meaning=#{meaningerror}"⋯outputvalid=false
warnings=1
status=1
meaning=error
1valid ← true, warnings ← 0, status ← 0, meaning ← success1valid→ true = true2warnings→ 0 = 034status→ 0 = if !validtrue5  16elsif warnings0 > 07  28else9  010end1112meaning→ success = case status013when 014  "success"15when 116  "error"17else18  "warning"19end2021puts "valid=#{validtrue}"22puts "warnings=#{warnings0}"23puts "status=#{status0}"24puts "meaning=#{meaningsuccess}"⋯outputvalid=true
warnings=0
status=0
meaning=success
1valid ← true, warnings ← 3, status ← 2, meaning ← warning1valid→ true = true2warnings→ 3 = 334status→ 2 = if !validtrue5  16elsif warnings3 > 07  28else9  010end1112meaning→ warning = case status213when 014  "success"15when 116  "error"17else18  "warning"19end2021puts "valid=#{validtrue}"22puts "warnings=#{warnings3}"23puts "status=#{status2}"24puts "meaning=#{meaningwarning}"⋯outputvalid=true
warnings=3
status=2
meaning=warning