Class: SafeMoney

Inherits:
Object
  • Object
show all
Defined in:
lib/safe_money.rb,
lib/safe_money/version.rb

Constant Summary collapse

CoercionError = 
Class.new(TypeError)
ArithmeticError = 
Class.new(ArgumentError)
VERSION = 
"0.0.2"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cents) ⇒ SafeMoney

Returns a new instance of SafeMoney.

Raises:

  • (ArgumentError) 


38
39
40
41
42
 
# File 'lib/safe_money.rb', line 38

def initialize cents
  raise ArgumentError, 'cents must be an Integer' unless cents.is_a?(Integer)
  @cents = cents
  freeze
end

Class Method Details

.cents(number) ⇒ Object Also known as: []

Raises:

  • (ArgumentError) 


10
11
12
13
14
15
16
17
18
19
20
 
# File 'lib/safe_money.rb', line 10

def cents number
  return number if number.is_a?(self)
  raise ArgumentError, 'cents must be Numeric' unless number.is_a?(Numeric)
  cents = if number.is_a?(Float)
    raise CoercionError, "#{number} cannot safely be converted into cents" unless number.to_i == number
    number.to_i
  else
    number
  end
  new cents
end

.dollars(number) ⇒ Object

Raises:

  • (ArgumentError) 


24
25
26
27
28
29
30
31
32
 
# File 'lib/safe_money.rb', line 24

def dollars number
  return number if number.is_a?(self)
  raise ArgumentError, 'dollars must be Numeric' unless number.is_a?(Numeric)
  if number != number.round(2)
    raise CoercionError, "#{number} cannot safely be converted into cents"
  end
  cents = (number * 100.00).round
  new cents
end

Instance Method Details

#*(number) ⇒ Object 



82
83
84
85
86
 
# File 'lib/safe_money.rb', line 82

def * number
  self.class.cents( to_f * number )
rescue CoercionError
  raise ArithmeticError, "#{self} cannot be safely multiplied by #{number}"
end

#+(number) ⇒ Object 



70
71
72
73
74
 
# File 'lib/safe_money.rb', line 70

def + number
  self.class.cents( to_i + number )
rescue CoercionError
  raise ArithmeticError, "#{number} cannot be safely added to #{self}"
end

#-(number) ⇒ Object 



76
77
78
79
80
 
# File 'lib/safe_money.rb', line 76

def - number
  self.class.cents( to_i - number )
rescue CoercionError
  raise ArithmeticError, "#{number} cannot be safely subtracted from #{self}"
end

#-@ ⇒ Object 



96
97
98
 
# File 'lib/safe_money.rb', line 96

def -@
  self.class.cents(-to_i)
end

#/(number) ⇒ Object Also known as: div 



88
89
90
91
92
 
# File 'lib/safe_money.rb', line 88

def / number
  self.class.cents( to_f / number )
rescue CoercionError
  raise ArithmeticError, "#{self} cannot be safely divided by #{number}"
end

#as_json(options = nil) ⇒ Object 



115
116
117
 
# File 'lib/safe_money.rb', line 115

def as_json options=nil
  to_i
end

#eql?(other) ⇒ Boolean

Returns:

  • (Boolean) 


56
57
58
59
 
# File 'lib/safe_money.rb', line 56

def eql? other
  other = other.to_i if self.class === other
  to_i.eql?(other)
end

#equal?(other) ⇒ Boolean

Returns:

  • (Boolean) 


61
62
63
64
 
# File 'lib/safe_money.rb', line 61

def equal? other
  other = other.to_i if self.class === other
  to_i.equal?(other)
end

#inspect ⇒ Object Also known as: to_s, to_str 



108
109
110
111
 
# File 'lib/safe_money.rb', line 108

def inspect
  dollars = to_dollars
  "#{'-' if dollars < 0}$#{sprintf('%.2f', dollars.abs)}"
end

#negative? ⇒ Boolean

Returns:

  • (Boolean) 


104
105
106
 
# File 'lib/safe_money.rb', line 104

def negative?
  self < 0
end

#positive? ⇒ Boolean

Returns:

  • (Boolean) 


100
101
102
 
# File 'lib/safe_money.rb', line 100

def positive?
  self > 0
end

#to_dollars ⇒ Object 



66
67
68
 
# File 'lib/safe_money.rb', line 66

def to_dollars
  (@cents * 0.01).round(2)
end

#to_i ⇒ Object 



44
45
46
 
# File 'lib/safe_money.rb', line 44

def to_i
  @cents
end

#to_param ⇒ Object 



119
120
121
 
# File 'lib/safe_money.rb', line 119

def to_param
  to_i.to_s
end