さくっとhashをテーブル出力したいときに使うやつ

table_printer.rb

class TablePrinter
  # Initialize data
  # @param data [Array] printing data as array of hash.
  # @param labels [Hash] column labels hash.
  # @example
  #   data = [
  #     { name: "foo", installed_versions: ["5.15.5_3"], current_version: "5.15.7" },
  #     { name: "bar", installed_versions: ["7.0.4"], current_version: "7.0.5" },
  #     { name: "baz", installed_versions: ["3.2.5"], current_version: "3.2.7" },
  #   ]
  #   labels = {
  #     name: "Name",
  #     installed_versions: "Installed Versions",
  #     current_version: "Current Version",
  #   }
  #   TablePrinter.new(data, labels)
  def initialize(data, labels)
    @data = data.map{ _1.map{ |k,v| [k.to_sym, v.is_a?(Array) ? v.join(", ") : v.to_s ]}.to_h }
    @columns = labels.each_with_object({}) do |(col, label), memo_obj|
      memo_obj[col.to_sym] = { label: label, width: [@data.map{ _1[col.to_sym]&.size || 0 }.max, label.size].max }
    end
  end

  # Print table
  def print
    write_divider
    write_header
    write_divider
    @data.each{ write_line(_1) }
    write_divider
  end

  private

  def write_header
    $stdout.puts "| #{ @columns.map{ |_k,v| v[:label].ljust(v[:width]) }.join(" | ") } |"
  end

  def write_divider
    $stdout.puts "+-#{ @columns.map{ |_k,v| "-"*v[:width] }.join("-+-") }-+"
  end

  def write_line(line)
    keys = @columns.keys
    str = keys.map{ |k| line[k].ljust(@columns.dig(k, :width) || 0) }.join(" | ")
    $stdout.puts "| #{str} |"
  end
end

# thanks: https://stackoverflow.com/a/28685559

# Example:
data = [
  { name: "foo", installed_versions: ["5.15.5_3"], current_version: "5.15.7" },
  { name: "bar", installed_versions: ["7.0.4"], current_version: "7.0.5" },
  { name: "baz", installed_versions: ["3.2.5"], current_version: "3.2.7" },
]
labels = {
  name: "Name",
  installed_versions: "Installed Versions",
  current_version: "Current Version",
}
tp = TablePrinter.new(data, labels)
tp.print
# +------+--------------------+-----------------+
# | Name | Installed Versions | Current Version |
# +------+--------------------+-----------------+
# | foo  | 5.15.5_3           | 5.15.7          |
# | bar  | 7.0.4              | 7.0.5           |
# | baz  | 3.2.5              | 3.2.7           |
# +------+--------------------+-----------------+