[expectations] Merge pull request rspec/rspec-expectations#521 from d…

…anielfone/2-99-maintenance

Deprecation warning on Has matcher

---
This commit was imported from rspec/rspec-expectations@9e0418f.

rspec-expectations/Changelog.md

@@ -11,6 +11,8 @@ Deprecations:
   `RSpec::Expectations::Configuration`. (Myron Marston)
 * Deprecate `be_xyz` predicate matcher on an object that doesn't respond to
   `xyz?` or `xyzs?`. (Daniel Fone)
+* Deprecate `have_xyz` matcher on an object that doesn't respond to `has_xyz?`.
+  (Daniel Fone)
 
 ### 2.99.0.beta2 / 2014-02-17
 [full changelog](http://github.com/rspec/rspec-expectations/compare/v2.99.0.beta1...v2.99.0.beta2)

rspec-expectations/lib/rspec/matchers/built_in/has.rb

@@ -9,7 +9,10 @@ def initialize(expected, *args)
         end
 
         def matches?(actual)
-          actual.__send__(predicate(@expected), *@args)
+          method = predicate(@expected)
+          result = actual.__send__(method, *@args)
+          check_respond_to(actual, method)
+          result
         end
 
         def failure_message_for_should
@@ -43,6 +46,13 @@ def failure_message_args_description
           desc = args_description
           "(#{desc})" if desc
         end
+
+        def check_respond_to(actual, method)
+          RSpec.deprecate(
+            "Matching with #{@expected} on an object that doesn't respond to `#{method}`",
+            :replacement => "`respond_to_missing?` or `respond_to?` on your object"
+          ) unless actual.respond_to?(method)
+        end
       end
     end
   end

rspec-expectations/spec/rspec/matchers/has_spec.rb

@@ -57,6 +57,16 @@ def o.has_sym?(*args)
       expect(o).to have_sym(:foo)
     }.to raise_error("Funky exception")
   end
+
+  it 'warns of deprecation when actual does not respond to #has_sym?' do
+    foo_class = Class.new do
+      def method_missing(method)
+        return true if method == :has_foo?
+      end
+    end
+    expect_deprecation_with_call_site(__FILE__, __LINE__ + 1, /Matching with have_foo on an object that doesn't respond to `has_foo\?`/)
+    expect(foo_class.new).to have_foo
+  end
 end
 
 describe "expect(...).not_to have_sym(*args)" do