Added failure scenario

features/rename_temp.feature

@@ -30,10 +30,7 @@ Feature: Rename temp
     Then the tool should return an error code
     Then the output should be:
       """
-      def name
-        fred = "fred"
-        "My name is " + fred
-      end
+      The starting extent was invalid.
 
       """
 

features/support/driver.rb

@@ -10,7 +10,7 @@ def run_refactoring(name, *args)
       end
 
       def last_output
-        @last_result.resulting_code
+        @last_result.to_s
       end
 
       def last_exit_status
@@ -52,6 +52,10 @@ def run_refactoring(name, *args)
         run("raffle #{name} #{args.join(' ')}")
       end
 
+      def last_output
+        all_output
+      end
+
       alias :assert_file_content :check_exact_file_content
     end
   end

lib/raffle/recorder.rb

@@ -2,23 +2,35 @@
 
 module Raffle
   class Recorder
+    def initialize
+      @errors = []
+    end
+
     def output_sexp(sexp)
       @output_sexp = sexp
       self
     end
 
+    def invalid_starting_exent(extent)
+      @errors << "The starting extent was invalid."
+    end
+
     def result
-      SuccessfulResult.new(@output_sexp)
+      if @errors.empty?
+        SuccessfulResult.new(@output_sexp)
+      else
+        FailedResult.new(@errors)
+      end
     end
   end
 
   class SuccessfulResult < Struct.new(:output_sexp)
-    def resulting_code
+    def to_s
       rubify(output_sexp)
     end
 
     def report
-      $stdout.puts(result)
+      $stdout.puts(self)
     end
 
     def rubify(sexpr)
@@ -29,4 +41,18 @@ def exit_status
       0
     end
   end
+
+  class FailedResult < Struct.new(:errors)
+    def to_s
+      errors.join("\n") + "\n"
+    end
+
+    def report
+      $stderr.puts(self)
+    end
+
+    def exit_status
+      1
+    end
+  end
 end

lib/raffle/refactorings/rename_temp.rb

@@ -9,6 +9,8 @@ class RenameTemp
 
       def call(starting_sexp, extent, extent_sexp, new_name, result)
         original_name = name_of_ident_at_position(starting_sexp, extent.start)
+        return result.invalid_starting_exent(extent) if original_name.nil?
+
         scope_sexp = containing_scope_for_position(starting_sexp, extent.start)
         unless_scope_defines_variable_again = lambda do |new_scope|
           not defining_block_parameter?(new_scope, original_name)
@@ -22,7 +24,8 @@ def call(starting_sexp, extent, extent_sexp, new_name, result)
       private
 
       def name_of_ident_at_position(starting_sexp, position)
-        sexp_for_position(starting_sexp, position)[1]
+        ident_candidate = sexp_for_position(starting_sexp, position)
+        ident_candidate[0] == :@ident ? ident_candidate[1] : nil
       end
 
       def sexp_for_position(starting_sexp, position)