have_spec.rb

require 'spec_helper'
require 'stringio'

describe "have matcher" do
  let(:inflector) do
    Class.new do
      def self.pluralize(string)
        string.to_s + 's'
      end
    end
  end

  before(:each) { stub_const("ActiveSupport::Inflector", inflector) }

  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)
      owner.add_to_collection_with_count_method(number)
    end
    owner
  end

  describe "expect(...).to have(n).items" do
    it_behaves_like "an RSpec matcher", :valid_value => [1, 2], :invalid_value => [1] do
      let(:matcher) { have(2).items }
    end

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

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

    it "converts a String argument to Integer" do
      owner = create_collection_owner_with(3)
      expect(owner).to have('3').items_in_collection_with_length_method
      expect(owner).to have('3').items_in_collection_with_size_method
      expect(owner).to have('3').items_in_collection_with_count_method
    end

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

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

  describe 'expect(...).to have(1).item when ActiveSupport::Inflector is defined' do

    it 'pluralizes the collection name' do
      owner = create_collection_owner_with(1)
      expect(owner).to have(1).item
    end

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

      it "does not pluralize the collection name" do
        stub_const("ActiveSupport::Inflector", Module.new)
        owner = create_collection_owner_with(1)
        expect {
          expect(owner).to have(1).item
        }.to raise_error(NoMethodError)
      end

    end
  end

  describe 'expect(...).to have(1).item when Inflector is defined' do
    before { stub_const("Inflector", inflector) }

    it 'pluralizes the collection name' do
      owner = create_collection_owner_with(1)
      expect(owner).to have(1).item
    end
  end

  describe "expect(...).to 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
      expect do
        expect(owner).to have(3).items
      end.to raise_error("expected items to be a collection but it does not respond to #length, #size or #count")
    end
  end

  describe "expect(...).not_to have(n).items" do

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

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

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

  describe "expect(...).to have_exactly(n).items" do

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

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

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

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

  describe "expect(...).to 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)
      expect(owner).to have_at_least(3).items_in_collection_with_length_method
      expect(owner).to have_at_least(3).items_in_collection_with_size_method
      expect(owner).to have_at_least(3).items_in_collection_with_count_method
    end

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

    it "fails if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      expect {
        expect(owner).to have_at_least(4).items_in_collection_with_length_method
      }.to fail_with("expected at least 4 items_in_collection_with_length_method, got 3")
      expect {
        expect(owner).to have_at_least(4).items_in_collection_with_size_method
      }.to fail_with("expected at least 4 items_in_collection_with_size_method, got 3")
      expect {
        expect(owner).to have_at_least(4).items_in_collection_with_count_method
      }.to fail_with("expected at least 4 items_in_collection_with_count_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
      count_matcher = have_at_least(3).items_in_collection_with_count_method

      #when
      length_matcher.matches?(owner)
      size_matcher.matches?(owner)
      count_matcher.matches?(owner)

      #then
      expect(length_matcher.failure_message_for_should_not).to eq <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  expect(actual).not_to have_at_least(3).items_in_collection_with_length_method
We recommend that you use this instead:
  expect(actual).to have_at_most(2).items_in_collection_with_length_method
EOF

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

  describe "expect(...).to 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)
      expect(owner).to have_at_most(3).items_in_collection_with_length_method
      expect(owner).to have_at_most(3).items_in_collection_with_size_method
      expect(owner).to have_at_most(3).items_in_collection_with_count_method
    end

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

    it "passes if target has a collection of items with < n members" do
      owner = create_collection_owner_with(3)
      expect(owner).to have_at_most(4).items_in_collection_with_length_method
      expect(owner).to have_at_most(4).items_in_collection_with_size_method
      expect(owner).to have_at_most(4).items_in_collection_with_count_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
      count_matcher = have_at_most(3).items_in_collection_with_count_method

      #when
      length_matcher.matches?(owner)
      size_matcher.matches?(owner)
      count_matcher.matches?(owner)

      #then
      expect(length_matcher.failure_message_for_should_not).to eq <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  expect(actual).not_to have_at_most(3).items_in_collection_with_length_method
We recommend that you use this instead:
  expect(actual).to have_at_least(4).items_in_collection_with_length_method
EOF

      expect(size_matcher.failure_message_for_should_not).to eq <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  expect(actual).not_to have_at_most(3).items_in_collection_with_size_method
We recommend that you use this instead:
  expect(actual).to have_at_least(4).items_in_collection_with_size_method
EOF

      expect(count_matcher.failure_message_for_should_not).to eq <<-EOF
Isn't life confusing enough?
Instead of having to figure out the meaning of this:
  expect(actual).not_to have_at_most(3).items_in_collection_with_count_method
We recommend that you use this instead:
  expect(actual).to have_at_least(4).items_in_collection_with_count_method
EOF
    end
  end

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

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

    it "fails when the number of items IN the collection is not as expected" do
      expect {
        expect([1,2,3]).to have(7).items
      }.to 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
      expect("this string").to have(11).characters
    end

    it "fails if the length is incorrect" do
      expect {
        expect("this string").to have(12).characters
      }.to 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
      expect {
        expect(Object.new).to have(2).things
      }.to raise_error(NoMethodError) { |e|
        expect(e.name).to eq :things
      }
    end
  end

  describe RSpec::Matchers::BuiltIn::Have, "for a collection owner that implements #send" do
    before(:each) do
      @collection = Object.new
      def @collection.floozles; [1,2] end
      def @collection.send; :sent; end
    end

    it "works in the straightforward case" do
      expect(@collection).to have(2).floozles
    end

    it "works when doing automatic pluralization" do
      expect(@collection).to have_at_least(1).floozle
    end

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

    it 'works when #send is defined directly on an array' do
      array = [1, 2]
      def array.send; :sent; end

      expect(array).to have(2).items
    end
  end

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

    it "does not respond_to? method_missing (because it's private)" do
      formatter = described_class.new(0, StringIO.new)
      expect(formatter).not_to 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
        expect(@have).to respond_to(@a_method_which_have_defines)
      end

      it "is true for a method that it's superclass (Object) defines" do
        expect(@have).to respond_to(@a_method_which_object_defines)
      end

      it "is false for a method which neither Object nor nor Have defines" do
        expect(@have).not_to respond_to(:foo_bar_baz)
      end

      it "is false if the owner doesn't respond to the method" do
        have = described_class.new(99)
        expect(have).not_to respond_to(:problems)
      end

      it "is true if the owner responds to the method" do
        have = described_class.new(:a_symbol)
        expect(have).to respond_to(:to_sym)
      end
    end
  end
end