def pretty(env, exception)
req = Rack::Request.new(env)
path = (req.script_name + req.path_info).squeeze("/")
frames = exception.backtrace.map { |line|
frame = OpenStruct.new
if line =~ /(.*?):(\d+)(:in `(.*)')?/
frame.filename = $1
frame.lineno = $2.to_i
frame.function = $4
begin
lineno = frame.lineno-1
lines = ::File.readlines(frame.filename)
frame.pre_context_lineno = [lineno-CONTEXT, 0].max
frame.pre_context = lines[frame.pre_context_lineno...lineno]
frame.context_line = lines[lineno].chomp
frame.post_context_lineno = [lineno+CONTEXT, lines.size].min
frame.post_context = lines[lineno+1..frame.post_context_lineno]
rescue
end
frame
else
nil
end
}.compact
env["rack.errors"].puts "#{exception.class}: #{exception.message}"
env["rack.errors"].puts exception.backtrace.map { |l| "\t" + l }
env["rack.errors"].flush
[@template.result(binding)]
end