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Wannabe Bool

If string, numeric, symbol and nil values wanna be a boolean value, they can with the new to_b method. Moreover, you can use WannabeBool::Attributes module to create predicate methods in your classes.

Installing

Gemfile

gem 'wannabe_bool'

Direct installation

$ gem install wannabe_bool

Using

to_b method is available on String, Symbol, Numeric, TrueClass, FalseClass and NilClass.

For sake of readability (and personal choice), to_b has two aliases:

• to_bool
• to_boolean

Given this example:

{
  one: 'value',
  two: 2,
  mobile?: params[:mobile].to_b
}

It could be "more readable" like this:

{
  one: 'value',
  two: 2,
  mobile?: params[:mobile].to_boolean
}

Don't forget to require the gem:

require 'wannabe_bool'

String

• Returns true if string is one of these values: t, true, on, y, yes, 1.
• Returns false if string is one of these values: f, false, off, n, no, 0.
• For invalid boolean string representations, returns false by default. See "Invalid Value Behaviour" section for more options.

It ignores trailing spaces and letter cases.

'1'.to_b    # => true
't'.to_b    # => true
'T'.to_b    # => true
'true'.to_b # => true
'TRUE'.to_b # => true
'on'.to_b   # => true
'ON'.to_b   # => true
'y'.to_b    # => true
'yes'.to_b  # => true
'YES'.to_b  # => true

' 1 '.to_b    # => true
' t '.to_b    # => true
' T '.to_b    # => true
' true '.to_b # => true
' TRUE '.to_b # => true
' on '.to_b   # => true
' ON '.to_b   # => true
' y '.to_b    # => true
'Y'.to_b      # => true
' Y '.to_b    # => true
' yes '.to_b  # => true
' YES '.to_b  # => true

'0'.to_b     # => false
'f'.to_b     # => false
'F'.to_b     # => false
'false'.to_b # => false
'FALSE'.to_b # => false
'off'.to_b   # => false
'OFF'.to_b   # => false
'n'.to_b     # => false
'N'.to_b     # => false
'no'.to_b    # => false
'NO'.to_b    # => false

' 0 '.to_b     # => false
' f '.to_b     # => false
' F '.to_b     # => false
' false '.to_b # => false
' FALSE '.to_b # => false
' off '.to_b   # => false
' OFF '.to_b   # => false
' n '.to_b     # => false
' N '.to_b     # => false
' no '.to_b    # => false
' NO '.to_b    # => false

''.to_b  # => false
' '.to_b # => false

Invalid Value Behaviour for strings

You can configure the result for invalid boolean string representations, using the WannabeBool.invalid_value_behaviour option.

There are 3 predefined behaviours available: to return false (default), nil or raise an ArgumentError:

WannabeBool.invalid_value_behaviour = WannabeBool::InvalidValueBehaviour::False
'wherever'.to_b # => false

WannabeBool.invalid_value_behaviour = WannabeBool::InvalidValueBehaviour::Nil
'wherever'.to_b # => nil

WannabeBool.invalid_value_behaviour = WannabeBool::InvalidValueBehaviour::Error
'wherever'.to_b # => ArgumentError: is not a valid boolean representation

Moreover, you can provide your own behaviour for invalid boolean string representations. Just set a proc or lambda, or even any class or object that responds to call method.

WannabeBool.invalid_value_behaviour = -> { :prodis }
'wherever'.to_b # => :prodis

Note that WannabeBool.invalid_value_behaviour is a global configuration. Said that, all the results for to_b method with invalid boolean string representations will be affected.

Symbol

Same as symbol.to_s.to_b.

:'1'.to_b  # => true
:t.to_b    # => true
:true.to_b # => true
:on.to_b   # => true
:y.to_b    # => true
:yes.to_b  # => true

:'0'.to_b   # => false
:f.to_b     # => false
:false.to_b # => false
:off.to_b   # => false
:n.to_b     # => false
:no.to_b    # => false

Numeric

Returns false if number is zero. Returns true otherwise.

Integer

0.to_b  # => false
1.to_b  # => true
2.to_b  # => true
-1.to_b # => true
-2.to_b # => true

Float

0.0.to_b  # => false
0.1.to_b  # => true
1.0.to_b  # => true
-0.1.to_b # => true
-1.0.to_b # => true

BigDecimal

require 'bigdecimal'

BigDecimal('0.0').to_b  # => false
BigDecimal('0.1').to_b  # => true
BigDecimal('1.0').to_b  # => true
BigDecimal('-0.1').to_b # => true
BigDecimal('-1.0').to_b # => true

TrueClass

Returns true.

true.to_b # => true

FalseClass

Returns false.

false.to_b # => false

NilClass

Returns false.

nil.to_b # => false

Creating predicate methods

class Fake
  include WannabeBool::Attributes

  attr_accessor :name, :main, :published
  attr_wannabe_bool :main, :published
end

fake = Fake.new
fake.main?      # => false
fake.published? # => false

fake.main = true
fake.main? # => true

fake.published = 1
fake.published? # => true

fake.main = 'true'
fake.main? # => true

fake.published = :true
fake.published? # => true

Changelog

See the changes in each version.

Author

Fernando Hamasaki de Amorim (prodis)

Contributing to wannabe_bool

See the contributing guide.