Calculate Redis-rb backoff and print a nice table

calculate_backoff.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'markdown-tables', '1.0.2'
end

attempts = ARGV[0].to_i
reconnect_delay = ARGV[1].to_f
reconnect_delay_max = ARGV[2].to_f

if [attempts, reconnect_delay, reconnect_delay_max].any?(&:nil?)
  puts 'calculate_backoff.rb'
  puts
  puts 'Usage:'
  puts 'ruby calculate_backoff.rb attempts reconnect_delay reconnect_delay_max'
  puts
  puts 'Example:'
  puts 'ruby calculate_backoff.rb 10 1.5 10'
  exit 1
end

labels = ['#', 'Attempt wait time', 'Total wait time']

data = [].tap do |it|
  total_wait_time = 0
  (1..attempts).each do |attempt|
    wait_time = [(reconnect_delay * 2**(attempt-1)), reconnect_delay_max].min
    total_wait_time += wait_time

    it << [attempt, "#{wait_time}s", "#{total_wait_time}s"]
  end
end

table = MarkdownTables.make_table(
  labels,
  data,
  is_rows: true,
  align: ['l', 'c', 'c'],
)

puts MarkdownTables.plain_text(table)
# puts MarkdownTables.make_table(labels, data, is_rows: true)

table_ascii

|====|===================|======================|
| #  | Attempt wait time |    Total wait time   |
|====|===================|======================|
| 1  |       0.1s        |         0.1s         |
|----|-------------------|----------------------|
| 2  |       0.2s        | 0.30000000000000004s |
|----|-------------------|----------------------|
| 3  |       0.4s        |  0.7000000000000001s |
|----|-------------------|----------------------|
| 4  |       0.8s        |         1.5s         |
|----|-------------------|----------------------|
| 5  |       1.5s        |         3.0s         |
|----|-------------------|----------------------|
| 6  |       1.5s        |         4.5s         |
|----|-------------------|----------------------|
| 7  |       1.5s        |         6.0s         |
|----|-------------------|----------------------|
| 8  |       1.5s        |         7.5s         |
|----|-------------------|----------------------|
| 9  |       1.5s        |         9.0s         |
|----|-------------------|----------------------|
| 10 |       1.5s        |         10.5s        |
|====|===================|======================|

table_markdown.md

#	Attempt wait time	Total wait time
1	0.1s	0.1s
2	0.2s	0.30000000000000004s
3	0.4s	0.7000000000000001s
4	0.8s	1.5s
5	1.5s	3.0s
6	1.5s	4.5s
7	1.5s	6.0s
8	1.5s	7.5s
9	1.5s	9.0s
10	1.5s	10.5s