add a simple return, ie the normal kind, not with trailing statements

test/parser/test_return.rb

@@ -0,0 +1,28 @@
+require_relative "helper"
+
+class TestReturn < MiniTest::Test
+  # include the magic (setup and parse -> test method translation), see there
+  include ParserHelper
+    
+  def test_return_int
+    @string_input = 'return 42'
+    @parse_output = {:return=>"return", :return_expression=>{:integer=>"42"}}
+    @transform_output = Ast::ReturnExpression.new(Ast::IntegerExpression.new(42) )
+    @parser = @parser.simple_return
+  end
+
+  def test_return_variable
+    @string_input = 'return foo'
+    @parse_output = {:return=>"return", :return_expression=>{:name=>"foo"}}
+    @transform_output = Ast::ReturnExpression.new(Ast::NameExpression.new("foo") )
+    @parser = @parser.simple_return
+  end
+
+  def test_return_string
+    @string_input    = 'return "hello"'
+    @parse_output = {:return=>"return", :return_expression=>{:string=>[{:char=>"h"}, {:char=>"e"}, {:char=>"l"}, {:char=>"l"}, {:char=>"o"}]}}
+    @transform_output = Ast::ReturnExpression.new(Ast::StringExpression.new("hello") )
+    @parser = @parser.simple_return
+  end
+
+end