require 'spec_helper'
module Alf
  module Operator::Relational
    describe Project do
        
      let(:operator_class){ Project }
      it_should_behave_like("An operator class")
        
      let(:input) {[
        {:a => "a", :b => "b"},
        {:a => "a", :b => "b"},
      ]}
  
      subject{ operator.to_a }
  
      describe "when used without --allbut" do
        let(:expected){[{:a => "a"}]}
  
        describe "and factored with commandline args" do
          let(:operator){ Project.run(["--", 'a']) }
          before{ operator.pipe(input) }
          it { should == expected } 
        end
  
        describe "and factored with Lispy" do
          let(:operator){ Lispy.project(input, [:a]) }
          it { should == expected } 
        end
  
      end # --no-allbut
  
      describe "when used with --allbut" do
        let(:expected){[{:b => "b"}]}
  
        describe "and factored with commandline args" do
          let(:operator){ Project.run(['--allbut', '--', 'a']) }
          before{ operator.pipe(input) }
          it { should == expected } 
        end
  
        describe "and factored with Lispy#project" do
          let(:operator){ Lispy.project(input, [:a], :allbut => true) }
          it { should == expected } 
        end
  
        describe "and factored with Lispy#allbut" do
          let(:operator){ Lispy.allbut(input, [:a]) }
          it { should == expected } 
        end
  
      end # --allbut
      
      describe "when all is projected" do
        let(:expected){[{}]}
        
        describe "when input is not empty" do
          let(:operator){ Lispy.project(input, []) }
          it { should == expected } 
        end
        
        describe "when input is empty" do
          let(:operator){ Lispy.project([], []) }
          it { should == [] } 
        end
        
        describe "when allbut is used" do
          let(:operator){ Lispy.project(input, [:a, :b], :allbut => true) }
          it { should == expected } 
        end
        
      end # all attributes projected
  
    end 
  end
end