initial stab at have_selector matcher for Strings

lib/capybara/rspec.rb

@@ -16,3 +16,34 @@ RSpec.configure do |config|
     end
   end
 end
+
+module Capybara
+  module RSpec
+    module StringMatchers
+      extend ::RSpec::Matchers::DSL
+
+      matcher :have_selector do |*args|
+        match_for_should do |string|
+          Capybara::string(string).has_selector?(*args)
+        end
+
+        match_for_should_not do |string|
+          Capybara::string(string).has_no_selector?(*args)
+        end
+
+        failure_message_for_should do |string|
+          "expected selector #{formatted(args)} to return something from:\n#{string}"
+        end
+
+        failure_message_for_should_not do |string|
+          "expected selector #{formatted(args)} not to return anything from:\n#{string}"
+        end
+
+        def formatted(args)
+          args.length == 1 ? args.first.inspect : args.inspect
+        end
+      end
+
+    end
+  end
+end

spec/rspec_spec.rb

@@ -45,3 +45,34 @@ describe 'capybara/rspec', :type => :other do
     expect { visit('/') }.to raise_error(NoMethodError)
   end
 end
+
+describe Capybara::RSpec::StringMatchers do
+  include Capybara::RSpec::StringMatchers
+  before { Capybara.default_selector = :css }
+  after  { Capybara.default_selector = :xpath }
+  describe "have_selector matcher" do
+    context "with should" do
+      it "passes if the String has_selector?" do
+        "<h1>Text</h1>".should have_selector('h1')
+      end
+
+      it "fails if the String returns false from has_selector?" do
+        expect do
+          "<h1>Text</h1>".should have_selector('h2')
+        end.to raise_error(/expected selector .* to return/)
+      end
+    end
+
+    context "with should_not" do
+      it "passes if has_no_selector? returns true" do
+        "<h1>Text</h1>".should_not have_selector('h2')
+      end
+
+      it "fails if has_no_selector? returns false" do
+        expect do
+          "<h1>Text</h1>".should_not have_selector('h1')
+        end.to raise_error(/expected selector .* not to return/)
+      end
+    end
+  end
+end