Move history pushing before command execution

This separates out concerns a little better, and paves the way for
extracing process_command from retreive_line.

lib/pry/commands/hist.rb

@@ -29,7 +29,8 @@ class Pry
     end
 
     def process
-      @history = Pry::Code(Pry.history.to_a)
+      # The last value in history will be the 'hist' command itself
+      @history = Pry::Code(Pry.history.to_a[0..-2])
 
       if opts.present?(:show)
         @history = @history.between(opts[:show])

lib/pry/pry_instance.rb

@@ -422,12 +422,10 @@ class Pry
     # Pry's input.
     interactive = !input.is_a?(StringIO)
 
-    begin
-      if !process_command(val, eval_string, target)
-        eval_string << "#{indented_val.chomp}\n" unless val.empty?
-      end
-    ensure
-      Pry.history << indented_val if interactive
+    Pry.history << indented_val if interactive
+
+    if !process_command(val, eval_string, target)
+      eval_string << "#{indented_val.chomp}\n" unless val.empty?
     end
   end
 

lib/pry/test/helper.rb

@@ -105,6 +105,7 @@ class PryTester
 
   def initialize(context = TOPLEVEL_BINDING, options = {})
     @pry = Pry.new(options)
+    @history = options[:history]
 
     if context
       target = Pry.binding_for(context)
@@ -122,6 +123,7 @@ class PryTester
 
     strs.flatten.each do |str|
       str = "#{str.strip}\n"
+      @history.push str if @history
       if @pry.process_command(str)
         result = last_command_result_or_output
       else

spec/commands/hist_spec.rb

@@ -6,7 +6,7 @@ describe "hist" do
     @hist = Pry.history
 
     @str_output = StringIO.new
-    @t = pry_tester do
+    @t = pry_tester :history => @hist do
       # For looking at what hist pushes into the input stack. The
       # implementation of this helper will definitely have to change at some
       # point.