require File.expand_path('../../../spec_helper', __FILE__)

ruby_version_is "1.9" do
  describe "Hash#assoc" do
    before(:each) do
      @h = {:apple => :green, :orange => :orange, :grape => :green, :banana => :yellow}
    end

    it "returns an Array if the argument is == to a key of the Hash" do
      @h.assoc(:apple).should be_an_instance_of(Array)
    end

    it "returns a 2-element Array if the argument is == to a key of the Hash" do
      @h.assoc(:grape).size.should == 2
    end

    it "sets the first element of the Array to the located key" do
      @h.assoc(:banana).first.should == :banana
    end

    it "sets the last element of the Array to the value of the located key" do
      @h.assoc(:banana).last.should == :yellow
    end

    it "only returns the first matching key-value pair for identity hashes" do
      @h.compare_by_identity
      @h['pear'] = :red
      @h['pear'] = :green
      @h.keys.grep(/pear/).size.should == 2
      @h.assoc('pear').should == ['pear', :red]
    end

    it "uses #== to compare the argument to the keys" do
      @h[1.0] = :value
      1.should == 1.0
      @h.assoc(1).should == [1.0, :value]
    end

    it "returns nil if the argument is not a key of the Hash" do
      @h.assoc(:green).should be_nil
    end

    it "returns nil if the argument is not a key of the Hash even when there is a default" do
      Hash.new(42).merge!( :foo => :bar ).assoc(42).should be_nil
      Hash.new{|h, k| h[k] = 42}.merge!( :foo => :bar ).assoc(42).should be_nil
    end
  end
end
