require 'spec_helper'
module Gisele::Language
  describe SugarRemoval do
    describe "if_st to case_st" do
      include AST::Helpers

      def ast(source)
        Syntax.ast(source.strip, :root => :if_st)
      end

      def rewrite(ast)
        SugarRemoval.new.call(ast)
      end

      it 'rewrites single if correctly' do
        source   = ast("if goodCond Task1 end")
        expected = \
          [:case_st,
            [:when_clause,
              [:bool_expr, [:var_ref, "goodCond"]],
              [:task_call_st, "Task1"] ]]
        rewrite(source).should eq(expected)
      end

      it 'negates the else clause' do
        source   = ast("if goodCond Task1 else Task2 end")
        expected = \
          [:case_st,
            [:when_clause,
              [:bool_expr, [:var_ref, "goodCond"]],
              [:task_call_st, "Task1"] ],
            [:when_clause,
              [:bool_expr, [:bool_not, [:var_ref, "goodCond"]]],
              [:task_call_st, "Task2"] ]
          ]
        rewrite(source).should eq(expected)
      end

      it 'handles elsif clauses correctly' do
        source = ast(<<-IF)
          if    c1 Task1
          elsif c2 Task2
          elsif c3 Task3
          else  Task4
          end
        IF
        expected = \
          [:case_st,
            [:when_clause,
              [:bool_expr, [:var_ref, "c1"]],
              [:task_call_st, "Task1"] ],
            [:when_clause,
              [:bool_expr, [:bool_and,
                [:var_ref, "c2"],
                [:bool_not, [:var_ref, "c1"]] ]],
              [:task_call_st, "Task2"] ],
            [:when_clause,
              [:bool_expr, [:bool_and,
                [:var_ref, "c3"],
                [:bool_and,
                  [:bool_not, [:var_ref, "c2"]],
                  [:bool_not, [:var_ref, "c1"]] ]]],
              [:task_call_st, "Task3"] ],
            [:when_clause,
              [:bool_expr, [:bool_and,
                [:bool_not, [:var_ref, "c3"]],
                [:bool_and,
                  [:bool_not, [:var_ref, "c2"]],
                  [:bool_not, [:var_ref, "c1"]]]]],
              [:task_call_st, "Task4"] ],
          ]
        rewrite(source).should eq(expected)
      end

      it 'avoids double negations' do
        source   = ast("if not(goodCond) Task1 else Task2 end")
        expected = \
          [:case_st,
            [:when_clause,
              [:bool_expr, [:bool_not, [:var_ref, "goodCond"]]],
              [:task_call_st, "Task1"] ],
            [:when_clause,
              [:bool_expr, [:var_ref, "goodCond"]],
              [:task_call_st, "Task2"] ] ]
        rewrite(source).should eq(expected)
      end

      it 'recurse on other nodes' do
        if_st = ast("if goodCond Task1 end")
        rw_st = rewrite(if_st)
        rewrite([:unit, if_st]).should eq([:unit, rw_st])
      end

      it 'keeps traceability markers on a single if' do
        if_st = ast("if goodCond Task1 end")
        rw_st = rewrite(if_st)
        rw_st.markers.should eq(if_st.markers)
        rw_st.last.markers.should eq(if_st.markers)
      end

      it 'keeps traceability markers when a else if present' do
        if_st = ast("if goodCond Task1 else Task2 end")
        rw_st = rewrite(if_st)
        rw_st.markers.should eq(if_st.markers)
        rw_st.last.markers.should eq(if_st.last.markers)
      end

    end
  end
end