add Util::TypeAnalysis

lib/spy/util.rb

@@ -0,0 +1,66 @@
+require 'spy'
+require 'set'
+
+module Spy
+  module Util
+    class TypeAnalysis
+      attr_reader :type_info
+
+      def initialize(spy)
+        @spy = spy
+        @type_info = {}
+      end
+
+      def decorate
+        if @spy.is_a?(Spy::Multi)
+          spies = @spy.spies
+        else
+          spies = [@spy]
+        end
+
+        spies.each do |spy|
+          spy.wrap do |method_call, &block|
+            record_args(method_call)
+            block.call
+            record_rv(method_call)
+          end
+        end
+
+        self
+      end
+
+      def respond_to_missing?(sym, incl_private = false)
+        @spy.respond_to_missing?(sym, incl_private)
+      end
+
+      def method_missing(sym, *args, &block)
+        @spy.send(sym, *args, &block)
+      end
+
+      private
+
+      def record_args(method_call)
+        @type_info[method_call.name] ||= {}
+        @type_info[method_call.name][:args] ||= []
+        method_call.args.each.with_index do |arg, idx|
+          @type_info[method_call.name][:args][idx] ||= Set.new
+          @type_info[method_call.name][:args][idx] << type_of(arg)
+        end
+      end
+
+      def record_rv(method_call)
+        @type_info[method_call.name] ||= {}
+        @type_info[method_call.name][:return_value] ||= Set.new
+        @type_info[method_call.name][:return_value] << type_of(method_call.result)
+      end
+
+      def type_of(obj)
+        if obj.is_a?(Array) && obj.size > 0
+          [Array, obj[0].class]
+        else
+          obj.class
+        end
+      end
+    end
+  end
+end

test/test_helper.rb

@@ -1,6 +1,7 @@
 # Add lib to load path
 $LOAD_PATH.push 'lib', __FILE__
 require 'spy'
+require 'spy/util'
 
 require 'coveralls'
 Coveralls.wear!

test/util_test.rb

@@ -0,0 +1,39 @@
+require 'test_helper'
+
+class UtilTest < Minitest::Spec
+  describe 'type analysis' do
+    it 'does things' do
+      klass = Class.new(Object)
+      klass.class_eval do
+        def name
+          "josh"
+        end
+
+        def compliment(color)
+          case color
+          when "red" then ["blue", "yellow"]
+          when "black" then "white"
+          else nil
+          end
+        end
+      end
+
+      multi = Spy.on_class(klass)
+      multi = Spy::Util::TypeAnalysis.new(multi).decorate
+      obj = klass.new
+
+      obj.name
+      obj.compliment("red")
+      obj.compliment("black")
+      obj.compliment("green")
+
+      type_info = multi.type_info
+
+      assert_equal [], type_info[:name][:args]
+      assert_equal [String], type_info[:name][:return_value].to_a
+
+      assert_equal [String], type_info[:compliment][:args][0].to_a
+      assert_equal [[Array, String], String, NilClass], type_info[:compliment][:return_value].to_a
+    end
+  end
+end