Seeking for the fastest "to boolean" implementation in ruby. See https://coderwall.com/p/inziba

bench_boolean.rb

require 'benchmark'
require 'set'

def to_boolean_eq(value)
  value == true || value == 'true' || value == 1 || value == '1' || value == 't'
end

def to_boolean_equal(value)
  value === true || value === 'true' || value === 1 || value === '1' || value === 't'
end

def to_boolean_when(value)
  case value
  when true, 'true', 1, '1', 't' then true
  else false
  end
end

def to_boolean_array(value)
  [true, 'true', 1, '1', 't'].include?(value)
end

def to_boolean_set(value)
  Set.new([true, 'true', 1, '1', 't']).include?(value)
end

TRUE_VALS_ARY = [true, 'true', 1, '1', 't']

def to_boolean_array_cached(value)
  TRUE_VALS_ARY.include?(value)
end

TRUE_VALS_SET = Set.new([true, 'true', 1, '1', 't'])

def to_boolean_set_cached(value)
  TRUE_VALS_SET.include?(value)
end


def benchmark(value, iterations = 100_000)

  puts <<-BAN
------------------------------------------------
Benchmark for #{value.class} '#{value}'
BAN

  Benchmark.bm(27) do |bm|
    bm.report(:to_boolean_eq) do
      iterations.times do
        to_boolean_eq(value)
      end
    end

    bm.report(:to_boolean_equal) do
      iterations.times do
        to_boolean_equal(value)
      end
    end

    bm.report(:to_boolean_when) do
      iterations.times do
        to_boolean_when(value)
      end
    end

    bm.report(:to_boolean_array) do
      iterations.times do
        to_boolean_array(value)
      end
    end

    bm.report(:to_boolean_set) do
      iterations.times do
        to_boolean_set(value)
      end
    end

    bm.report(:to_boolean_array_cached) do
      iterations.times do
        to_boolean_array(value)
      end
    end

    bm.report(:to_boolean_set_cached) do
      iterations.times do
        to_boolean_set(value)
      end
    end
  end

end

benchmark(true)
benchmark('t')
benchmark('false')

# $ ruby bench_boolean.rb 
# ------------------------------------------------
# Benchmark for TrueClass 'true'
#                                   user     system      total        real
# to_boolean_eq                 0.010000   0.000000   0.010000 (  0.010257)
# to_boolean_equal              0.010000   0.000000   0.010000 (  0.010859)
# to_boolean_when               0.010000   0.000000   0.010000 (  0.011311)
# to_boolean_array              0.050000   0.000000   0.050000 (  0.050133)
# to_boolean_set                0.370000   0.000000   0.370000 (  0.369136)
# to_boolean_array_cached       0.050000   0.000000   0.050000 (  0.050569)
# to_boolean_set_cached         0.380000   0.000000   0.380000 (  0.386393)
# ------------------------------------------------
# Benchmark for String 't'
#                                   user     system      total        real
# to_boolean_eq                 0.060000   0.000000   0.060000 (  0.055832)
# to_boolean_equal              0.060000   0.000000   0.060000 (  0.060313)
# to_boolean_when               0.040000   0.000000   0.040000 (  0.043082)
# to_boolean_array              0.100000   0.000000   0.100000 (  0.093800)
# to_boolean_set                0.370000   0.000000   0.370000 (  0.369338)
# to_boolean_array_cached       0.090000   0.000000   0.090000 (  0.089801)
# to_boolean_set_cached         0.380000   0.000000   0.380000 (  0.389204)
# ------------------------------------------------
# Benchmark for String 'false'
#                                   user     system      total        real
# to_boolean_eq                 0.060000   0.000000   0.060000 (  0.053945)
# to_boolean_equal              0.050000   0.000000   0.050000 (  0.053510)
# to_boolean_when               0.040000   0.000000   0.040000 (  0.041162)
# to_boolean_array              0.090000   0.000000   0.090000 (  0.087059)
# to_boolean_set                0.360000   0.000000   0.360000 (  0.365578)
# to_boolean_array_cached       0.090000   0.000000   0.090000 (  0.087375)
# to_boolean_set_cached         0.380000   0.000000   0.380000 (  0.384433)

conversions.rb

module Conversions

module_function

  def Boolean(value)
    case value
    when true, 'true', 1, '1', 't' then true
    when false, 'false', nil, '', 0, '0', 'f' then false
    else
      raise ArgumentError, "invalid value for Boolean(): \"#{value.inspect}\""
    end
  end

end

conversions_spec.rb

require 'spec_helper'

describe Conversions do

  describe '.Boolean' do

    context 'given truthy values' do
      [true, 'true', 1, '1', 't'].each do |val|
        it "returns true for '#{val}' (#{val.class})" do
          expect( Conversions.Boolean(val) ).to be true
        end
      end
    end

    context 'given falsey values' do
      [false, 'false', nil, '', 0, 0.0, '0', 'f'].each do |val|
        it "returns false for '#{val}' (#{val.class})" do
          expect( Conversions.Boolean(val) ).to be false
        end
      end
    end

    context 'given not meaningful values' do
      ['fail', 2, -1, 0.1].each do |val|
        it "raises ArgumentError for '#{val}' (#{val.class})" do
          expect{ Conversions.Boolean(val) }.to raise_error ArgumentError
        end
      end
    end
  end

end

conversions_spec.txt

Conversions
  .Boolean
    given falsey values
      returns false for 'false' (String)
      returns false for '0.0' (Float)
      returns false for '' (NilClass)
      returns false for '0' (Fixnum)
      returns false for '' (String)
      returns false for 'false' (FalseClass)
      returns false for '0' (String)
      returns false for 'f' (String)
    given truthy values
      returns true for 'true' (String)
      returns true for 't' (String)
      returns true for '1' (Fixnum)
      returns true for '1' (String)
      returns true for 'true' (TrueClass)
    given not meaningful values
      raises ArgumentError for '2' (Fixnum)
      raises ArgumentError for 'fail' (String)
      raises ArgumentError for '-1' (Fixnum)
      raises ArgumentError for '0.1' (Float)