Use `coverage` gem to check method call count in Ruby.

coverage gem of ruby 2.5 can get method coverage. so, I wrote a code to check the count of the method call.

sample code. (fizzbuzz.rb)

def fizz
  "Fizz"
end

def buzz
  "Buzz"
end

def fizzbuzz
  "FizzBuzz"
end

1.upto(100) do |n|
  if n % 15 == 0
    puts fizzbuzz
  elsif n % 3 == 0
    puts fizz
  elsif n % 5 == 0
    puts buzz
  else
    puts n
  end
end

check code (RUBY_VERSION >= "2.5.0")
It use termianl-table to make the results easy to see.

require "coverage"
require "terminal-table"

Coverage.start(methods: true)
require_relative "fizzbuzz"
result = Coverage.result

rows = []

result.each do |filepath, coverage_data|
  filename = File.basename(filepath)
  methods = coverage_data[:methods]

  methods.each do |method_data, count|
    next if count.zero?

    defined_class, method_id, _from_row, _from_col, _to_row, _to_col = *method_data
    rows << [filename, defined_class, method_id, count]
  end
end

header = %w(filename defined_class method_id count)
rows.sort_by! { |e| -e.last }
table = Terminal::Table.new headings: header, rows: rows
puts table

Result

.
.
# display fizzbuzz.rb result
.
.
+-------------+---------------+-----------+-------+
| filename    | defined_class | method_id | count |
+-------------+---------------+-----------+-------+
| fizzbuzz.rb | Object        | fizz      | 27    |
| fizzbuzz.rb | Object        | buzz      | 14    |
| fizzbuzz.rb | Object        | fizzbuzz  | 6     |
+-------------+---------------+-----------+-------+

looks to good.

Comments

[Ben Halpern]

Ah it's great to immediately visualize how this might look. I'd been thinking mostly abstractly about this component of 2.5. I'm really excited about the future of Ruby. I feel like Maz and the community are making nice improvements here and there whenever I look.