have_spec.rb

require 'spec_helper'
require 'stringio'

describe "have matcher" do

  before(:each) do
    if defined?(::ActiveSupport::Inflector) && ::ActiveSupport::Inflector.respond_to?(:pluralize)
      @active_support_was_defined = true
    else
      @active_support_was_defined = false
      module ::ActiveSupport
        class Inflector
          def self.pluralize(string)
            string.to_s + 's'
          end
        end
      end
    end
  end

  def create_collection_owner_with(n)
    owner = RSpec::Expectations::Helper::CollectionOwner.new
    (1..n).each do |number|
      owner.add_to_collection_with_length_method(number)
      owner.add_to_collection_with_size_method(number)
    end
    owner
  end

  describe "should have(n).items" do

    it "passes if target has a collection of items with n members" do
      owner = create_collection_owner_with(3)
      owner.should have(3).items_in_collection_with_length_method
      owner.should have(3).items_in_collection_with_size_method
    end

    it "converts :no to 0" do
      owner = create_collection_owner_with(0)
      owner.should have(:no).items_in_collection_with_length_method
      owner.should have(:no).items_in_collection_with_size_method
    end

    it "fails if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have(4).items_in_collection_with_length_method
      }.should fail_with("expected 4 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have(4).items_in_collection_with_size_method
      }.should fail_with("expected 4 items_in_collection_with_size_method, got 3")
    end
    
    it "fails if target has a collection of items with > n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have(2).items_in_collection_with_length_method
      }.should fail_with("expected 2 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have(2).items_in_collection_with_size_method
      }.should fail_with("expected 2 items_in_collection_with_size_method, got 3")
    end
  end

  describe 'should have(1).item when ActiveSupport::Inflector is defined' do
    
    it 'pluralizes the collection name' do
      owner = create_collection_owner_with(1)
      owner.should have(1).item
    end

    context "when ActiveSupport::Inflector is partially loaded without its inflectors" do

      it "does not pluralize the collection name" do
        (class << ::ActiveSupport::Inflector; self; end).send :undef_method, :pluralize
        owner = create_collection_owner_with(1)
        expect { owner.should have(1).item }.to raise_error(NoMethodError)
      end

    end
    
    after(:each) do
      unless @active_support_was_defined
        Object.__send__ :remove_const, :ActiveSupport
      end
    end
  end

  describe 'should have(1).item when Inflector is defined' do
    
    before(:each) do
      if defined?(Inflector)
        @inflector_was_defined = true
      else
        @inflector_was_defined = false
        class ::Inflector
          def self.pluralize(string)
            string.to_s + 's'
          end
        end
      end
    end
    
    it 'pluralizes the collection name' do
      owner = create_collection_owner_with(1)
      owner.should have(1).item
    end

    after(:each) do
      unless @inflector_was_defined
        Object.__send__ :remove_const, :Inflector
      end
    end
  end

  describe "should have(n).items where result responds to items but returns something other than a collection" do
    it "provides a meaningful error" do
      owner = Class.new do
        def items
          Object.new
        end
      end.new
      lambda do
        owner.should have(3).items
      end.should raise_error("expected items to be a collection but it does not respond to #length or #size")
    end
  end

  describe "should_not have(n).items" do

    it "passes if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      owner.should_not have(4).items_in_collection_with_length_method
      owner.should_not have(4).items_in_collection_with_size_method
    end
    
    it "passes if target has a collection of items with > n members" do
      owner = create_collection_owner_with(3)
      owner.should_not have(2).items_in_collection_with_length_method
      owner.should_not have(2).items_in_collection_with_size_method
    end

    it "fails if target has a collection of items with n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should_not have(3).items_in_collection_with_length_method
      }.should fail_with("expected target not to have 3 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should_not have(3).items_in_collection_with_size_method
        }.should fail_with("expected target not to have 3 items_in_collection_with_size_method, got 3")
    end
  end

  describe "should have_exactly(n).items" do

    it "passes if target has a collection of items with n members" do
      owner = create_collection_owner_with(3)
      owner.should have_exactly(3).items_in_collection_with_length_method
      owner.should have_exactly(3).items_in_collection_with_size_method
    end

    it "converts :no to 0" do
      owner = create_collection_owner_with(0)
      owner.should have_exactly(:no).items_in_collection_with_length_method
      owner.should have_exactly(:no).items_in_collection_with_size_method
    end

    it "fails if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have_exactly(4).items_in_collection_with_length_method
      }.should fail_with("expected 4 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have_exactly(4).items_in_collection_with_size_method
      }.should fail_with("expected 4 items_in_collection_with_size_method, got 3")
    end
    
    it "fails if target has a collection of items with > n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have_exactly(2).items_in_collection_with_length_method
      }.should fail_with("expected 2 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have_exactly(2).items_in_collection_with_size_method
      }.should fail_with("expected 2 items_in_collection_with_size_method, got 3")
    end
  end

  describe "should have_at_least(n).items" do

    it "passes if target has a collection of items with n members" do
      owner = create_collection_owner_with(3)
      owner.should have_at_least(3).items_in_collection_with_length_method
      owner.should have_at_least(3).items_in_collection_with_size_method
    end
    
    it "passes if target has a collection of items with > n members" do
      owner = create_collection_owner_with(3)
      owner.should have_at_least(2).items_in_collection_with_length_method
      owner.should have_at_least(2).items_in_collection_with_size_method
    end

    it "fails if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have_at_least(4).items_in_collection_with_length_method
      }.should fail_with("expected at least 4 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have_at_least(4).items_in_collection_with_size_method
      }.should fail_with("expected at least 4 items_in_collection_with_size_method, got 3")
    end
    
    it "provides educational negative failure messages" do
      #given
      owner = create_collection_owner_with(3)
      length_matcher = have_at_least(3).items_in_collection_with_length_method
      size_matcher = have_at_least(3).items_in_collection_with_size_method
      
      #when
      length_matcher.matches?(owner)
      size_matcher.matches?(owner)
      
      #then
      length_matcher.failure_message_for_should_not.should == <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  should_not have_at_least(3).items_in_collection_with_length_method
We recommend that you use this instead:
  should have_at_most(2).items_in_collection_with_length_method
EOF

      size_matcher.failure_message_for_should_not.should == <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  should_not have_at_least(3).items_in_collection_with_size_method
We recommend that you use this instead:
  should have_at_most(2).items_in_collection_with_size_method
EOF
    end
  end

  describe "should have_at_most(n).items" do
    it "passes if target has a collection of items with n members" do
      owner = create_collection_owner_with(3)
      owner.should have_at_most(3).items_in_collection_with_length_method
      owner.should have_at_most(3).items_in_collection_with_size_method
    end

    it "fails if target has a collection of items with > n members" do
      owner = create_collection_owner_with(3)
      lambda {
        owner.should have_at_most(2).items_in_collection_with_length_method
      }.should fail_with("expected at most 2 items_in_collection_with_length_method, got 3")
      lambda {
        owner.should have_at_most(2).items_in_collection_with_size_method
      }.should fail_with("expected at most 2 items_in_collection_with_size_method, got 3")
    end
    
    it "passes if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      owner.should have_at_most(4).items_in_collection_with_length_method
      owner.should have_at_most(4).items_in_collection_with_size_method
    end

    it "provides educational negative failure messages" do
      #given
      owner = create_collection_owner_with(3)
      length_matcher = have_at_most(3).items_in_collection_with_length_method
      size_matcher = have_at_most(3).items_in_collection_with_size_method
      
      #when
      length_matcher.matches?(owner)
      size_matcher.matches?(owner)
      
      #then
      length_matcher.failure_message_for_should_not.should == <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  should_not have_at_most(3).items_in_collection_with_length_method
We recommend that you use this instead:
  should have_at_least(4).items_in_collection_with_length_method
EOF
      
      size_matcher.failure_message_for_should_not.should == <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  should_not have_at_most(3).items_in_collection_with_size_method
We recommend that you use this instead:
  should have_at_least(4).items_in_collection_with_size_method
EOF
    end
  end

  describe "have(n).items(args, block)" do
    it "passes args to target" do
      target = mock("target")
      target.should_receive(:items).with("arg1","arg2").and_return([1,2,3])
      target.should have(3).items("arg1","arg2")
    end

    it "passes block to target" do
      target = mock("target")
      block = lambda { 5 }
      target.should_receive(:items).with("arg1","arg2", block).and_return([1,2,3])
      target.should have(3).items("arg1","arg2", block)
    end
  end

  describe "have(n).items where target IS a collection" do
    it "references the number of items IN the collection" do
      [1,2,3].should have(3).items
    end

    it "fails when the number of items IN the collection is not as expected" do
      lambda { [1,2,3].should have(7).items }.should fail_with("expected 7 items, got 3")
    end
  end

  describe "have(n).characters where target IS a String" do
    it "passes if the length is correct" do
      "this string".should have(11).characters
    end

    it "fails if the length is incorrect" do
      lambda { "this string".should have(12).characters }.should fail_with("expected 12 characters, got 11")
    end
  end

  describe "have(n).things on an object which is not a collection nor contains one" do
    it "fails" do
      lambda { Object.new.should have(2).things }.should raise_error(NoMethodError, /undefined method `things' for #<Object:/)
    end
  end

  describe RSpec::Matchers::Have, "for a collection owner that implements #send" do
    before(:each) do
      @collection = Object.new
      def @collection.floozles; [1,2] end
      def @collection.send(*args); raise "DOH! Library developers shouldn't use #send!" end
    end
    
    it "works in the straightforward case" do
      lambda {
        @collection.should have(2).floozles
      }.should_not raise_error
    end

    it "works when doing automatic pluralization" do
      lambda {
        @collection.should have_at_least(1).floozle
      }.should_not raise_error
    end

    it "blows up when the owner doesn't respond to that method" do
      lambda {
        @collection.should have(99).problems
      }.should raise_error(NoMethodError, /problems/)
    end
  end

  describe RSpec::Matchers::Have do
    it "has method_missing as private" do
      described_class.private_instance_methods.should include_method(:method_missing)
    end

    it "does not respond_to? method_missing (because it's private)" do
      formatter = described_class.new({ }, StringIO.new)
      formatter.should_not respond_to(:method_missing)
    end

    describe "respond_to?" do
      before :each do
        @have = described_class.new(:foo)
        @a_method_which_have_defines = described_class.instance_methods.first
        @a_method_which_object_defines = Object.instance_methods.first
      end
      
      it "is true for a method which Have defines" do
        @have.should respond_to(@a_method_which_have_defines)
      end
      
      it "is true for a method that it's superclass (Object) defines" do
        @have.should respond_to(@a_method_which_object_defines)
      end
      
      it "is false for a method which neither Object nor nor Have defines" do
        @have.should_not respond_to(:foo_bar_baz)
      end
      
      it "is false if the owner doesn't respond to the method" do
        have = described_class.new(99)
        have.should_not respond_to(:problems)
      end
      
      it "is true if the owner responds to the method" do
        have = described_class.new(:a_symbol)
        have.should respond_to(:to_sym)
      end
    end
  end
end