Allow :wait as an option to find, closes #974

lib/capybara/node/finders.rb

@@ -19,14 +19,15 @@ module Capybara
       #     page.find('li', :text => 'Quox').click_link('Delete')
       #
       # @param (see Capybara::Node::Finders#all)
-      # @option options [Boolean] match       The matching strategy to use.
+      # @option options [Boolean] match        The matching strategy to use.
+      # @option options [false, Numeric] wait  How long to wait for the element to appear.
       #
-      # @return [Capybara::Element]           The found element
-      # @raise  [Capybara::ElementNotFound]   If the element can't be found before time expires
+      # @return [Capybara::Element]            The found element
+      # @raise  [Capybara::ElementNotFound]    If the element can't be found before time expires
       #
       def find(*args)
-        synchronize do
-          query = Capybara::Query.new(*args)
+        query = Capybara::Query.new(*args)
+        synchronize(query.wait) do
           if query.match == :smart or query.match == :prefer_exact
             result = resolve_query(query, true)
             result = resolve_query(query, false) if result.size == 0 and not query.exact?

lib/capybara/query.rb

@@ -2,7 +2,7 @@ module Capybara
   class Query
     attr_accessor :selector, :locator, :options, :expression, :find, :negative
 
-    VALID_KEYS = [:text, :visible, :between, :count, :maximum, :minimum, :exact, :match]
+    VALID_KEYS = [:text, :visible, :between, :count, :maximum, :minimum, :exact, :match, :wait]
     VALID_MATCH = [:first, :smart, :prefer_exact, :one]
 
     def initialize(*args)
@@ -83,6 +83,14 @@ module Capybara
       end
     end
 
+    def wait
+      if options.has_key?(:wait)
+        @options[:wait] or 0
+      else
+        Capybara.default_wait_time
+      end
+    end
+
     def exact?
       if options.has_key?(:exact)
         @options[:exact]

lib/capybara/spec/session/find_spec.rb

@@ -27,6 +27,30 @@ Capybara::SpecHelper.spec '#find' do
     @session.find(:css, "a#has-been-clicked").text.should include('Has been clicked')
   end
 
+  context "with :wait option", :requires => [:js] do
+    it "should not wait for asynchronous load when `false` given" do
+      @session.visit('/with_js')
+      @session.click_link('Click me')
+      expect do
+        @session.find(:css, "a#has-been-clicked", :wait => false)
+      end.to raise_error(Capybara::ElementNotFound)
+    end
+
+    it "should not find element if it appears after given wait duration" do
+      @session.visit('/with_js')
+      @session.click_link('Click me')
+      expect do
+        @session.find(:css, "a#has-been-clicked", :wait => 0.2)
+      end.to raise_error(Capybara::ElementNotFound)
+    end
+
+    it "should find element if it appears before given wait duration" do
+      @session.visit('/with_js')
+      @session.click_link('Click me')
+      @session.find(:css, "a#has-been-clicked", :wait => 0.9).text.should include('Has been clicked')
+    end
+  end
+
   context "with frozen time", :requires => [:js] do
     it "raises an error suggesting that Capybara is stuck in time" do
       @session.visit('/with_js')