vendor/gems/rspec-1.1.2/lib/spec/matchers/have.rb

   1 module Spec
   2   module Matchers
   3
   4     class Have #:nodoc:
   5       def initialize(expected, relativity=:exactly)
   6         @expected = (expected == :no ? 0 : expected)
   7         @relativity = relativity
   8       end
   9
  10       def relativities
  11         @relativities ||= {
  12           :exactly => "",
  13           :at_least => "at least ",
  14           :at_most => "at most "
  15         }
  16       end
  17
  18       def method_missing(sym, *args, &block)
  19         @collection_name = sym
  20         @plural_collection_name = Inflector.pluralize(sym.to_s) if Object.const_defined?(:Inflector)
  21         @args = args
  22         @block = block
  23         self
  24       end
  25
  26       def matches?(collection_owner)
  27         if collection_owner.respond_to?(@collection_name)
  28           collection = collection_owner.send(@collection_name, *@args, &@block)
  29         elsif (@plural_collection_name && collection_owner.respond_to?(@plural_collection_name))
  30           collection = collection_owner.send(@plural_collection_name, *@args, &@block)
  31         elsif (collection_owner.respond_to?(:length) || collection_owner.respond_to?(:size))
  32           collection = collection_owner
  33         else
  34           collection_owner.send(@collection_name, *@args, &@block)
  35         end
  36         @actual = collection.size if collection.respond_to?(:size)
  37         @actual = collection.length if collection.respond_to?(:length)
  38         raise not_a_collection if @actual.nil?
  39         return @actual >= @expected if @relativity == :at_least
  40         return @actual <= @expected if @relativity == :at_most
  41         return @actual == @expected
  42       end
  43
  44       def not_a_collection
  45         "expected #{@collection_name} to be a collection but it does not respond to #length or #size"
  46       end
  47
  48       def failure_message
  49         "expected #{relative_expectation} #{@collection_name}, got #{@actual}"
  50       end
  51
  52       def negative_failure_message
  53         if @relativity == :exactly
  54           return "expected target not to have #{@expected} #{@collection_name}, got #{@actual}"
  55         elsif @relativity == :at_most
  56           return <<-EOF
  57 Isn't life confusing enough?
  58 Instead of having to figure out the meaning of this:
  59   should_not have_at_most(#{@expected}).#{@collection_name}
  60 We recommend that you use this instead:
  61   should have_at_least(#{@expected + 1}).#{@collection_name}
  62 EOF
  63         elsif @relativity == :at_least
  64           return <<-EOF
  65 Isn't life confusing enough?
  66 Instead of having to figure out the meaning of this:
  67   should_not have_at_least(#{@expected}).#{@collection_name}
  68 We recommend that you use this instead:
  69   should have_at_most(#{@expected - 1}).#{@collection_name}
  70 EOF
  71         end
  72       end
  73
  74       def description
  75         "have #{relative_expectation} #{@collection_name}"
  76       end
  77
  78       private
  79
  80       def relative_expectation
  81         "#{relativities[@relativity]}#{@expected}"
  82       end
  83     end
  84
  85     # :call-seq:
  86     #   should have(number).named_collection__or__sugar
  87     #   should_not have(number).named_collection__or__sugar
  88     #
  89     # Passes if receiver is a collection with the submitted
  90     # number of items OR if the receiver OWNS a collection
  91     # with the submitted number of items.
  92     #
  93     # If the receiver OWNS the collection, you must use the name
  94     # of the collection. So if a <tt>Team</tt> instance has a
  95     # collection named <tt>#players</tt>, you must use that name
  96     # to set the expectation.
  97     #
  98     # If the receiver IS the collection, you can use any name
  99     # you like for <tt>named_collection</tt>. We'd recommend using
 100     # either "elements", "members", or "items" as these are all
 101     # standard ways of describing the things IN a collection.
 102     #
 103     # This also works for Strings, letting you set an expectation
 104     # about its length
 105     #
 106     # == Examples
 107     #
 108     #   # Passes if team.players.size == 11
 109     #   team.should have(11).players
 110     #
 111     #   # Passes if [1,2,3].length == 3
 112     #   [1,2,3].should have(3).items #"items" is pure sugar
 113     #
 114     #   # Passes if "this string".length == 11
 115     #   "this string".should have(11).characters #"characters" is pure sugar
 116     def have(n)
 117       Matchers::Have.new(n)
 118     end
 119     alias :have_exactly :have
 120
 121     # :call-seq:
 122     #   should have_at_least(number).items
 123     #
 124     # Exactly like have() with >=.
 125     #
 126     # == Warning
 127     #
 128     # +should_not+ +have_at_least+ is not supported
 129     def have_at_least(n)
 130       Matchers::Have.new(n, :at_least)
 131     end
 132
 133     # :call-seq:
 134     #   should have_at_most(number).items
 135     #
 136     # Exactly like have() with <=.
 137     #
 138     # == Warning
 139     #
 140     # +should_not+ +have_at_most+ is not supported
 141     def have_at_most(n)
 142       Matchers::Have.new(n, :at_most)
 143     end
 144   end
 145 end