Raise error when invalid keys given

lib/capybara/query.rb

@@ -2,8 +2,11 @@ module Capybara
   class Query
     attr_accessor :selector, :locator, :options, :xpath, :find, :negative
 
+    VALID_KEYS = [:text, :visible, :between, :count, :maximum, :minimum]
+
     def initialize(*args)
       @options = if args.last.is_a?(Hash) then args.pop.dup else {} end
+
       unless options.has_key?(:visible)
         @options[:visible] = Capybara.ignore_hidden_elements
       end
@@ -18,6 +21,8 @@ def initialize(*args)
       @selector ||= Selector.all[Capybara.default_selector]
 
       @xpath = @selector.call(@locator).to_s
+
+      assert_valid_keys!
     end
 
     def name; selector.name; end
@@ -57,5 +62,17 @@ def matches_count?(count)
         count > 0
       end
     end
+
+  private
+
+    def assert_valid_keys!
+      valid_keys = VALID_KEYS + @selector.custom_filters.keys
+      invalid_keys = @options.keys - valid_keys
+      unless invalid_keys.empty?
+        invalid_names = invalid_keys.map(&:inspect).join(", ")
+        valid_names = valid_keys.map(&:inspect).join(", ")
+        raise ArgumentError, "invalid keys #{invalid_names}, should be one of #{valid_names}"
+      end
+    end
   end
 end

lib/capybara/spec/session/all_spec.rb

@@ -21,6 +21,10 @@
       @result.should include('Smith', 'John', 'John Smith')
     end
 
+    it "should raise an error when given invalid options" do
+      expect { @session.all('//p', :schmoo => "foo") }.to raise_error(ArgumentError)
+    end
+
     context "with css selectors" do
       it "should find all elements using the given selector" do
         @session.all(:css, 'h1').first.text.should == 'This is a test'