Added assert_select* for CSS selector-based testing (deprecates assert_tag) #5936 [assaf.arkin@gmail.com]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4929 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 557 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/assert_select.rb b/actionpack/lib/action_controller/assert_select.rb
new file mode 100644
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+++ b/actionpack/lib/action_controller/assert_select.rb
@@ -0,0 +1,557 @@
+#--
+# Copyright (c) 2006 Assaf Arkin (http://labnotes.org)
+# Under MIT and/or CC By license.
+#++
+
+require 'test/unit'
+require 'test/unit/assertions'
+require 'rexml/document'
+require File.dirname(__FILE__) + "/vendor/html-scanner/html/document"
+
+
+module ActionController
+  module Assertions
+    # Adds the #assert_select method for use in Rails functional
+    # test cases.
+    #
+    # Use #assert_select to make assertions on the response HTML of a controller
+    # action. You can also call #assert_select within another #assert_select to
+    # make assertions on elements selected by the enclosing assertion.
+    #
+    # Use #css_select to select elements without making an assertions, either
+    # from the response HTML or elements selected by the enclosing assertion.
+    #
+    # In addition to HTML responses, you can make the following assertions:
+    # * #assert_select_rjs    -- Assertions on HTML content of RJS update and
+    #     insertion operations.
+    # * #assert_select_encoded  -- Assertions on HTML encoded inside XML,
+    #     for example for dealing with feed item descriptions.
+    # * #assert_select_email    -- Assertions on the HTML body of an e-mail.
+    # 
+    # Also see HTML::Selector for learning how to use selectors.
+    module SelectorAssertions
+      # :call-seq:
+      #   css_select(selector) => array
+      #   css_select(element, selector) => array
+      #
+      # Select and return all matching elements.
+      #
+      # If called with a single argument, uses that argument as a selector
+      # to match all elements of the current page. Returns an empty array
+      # if no match is found.
+      #
+      # If called with two arguments, uses the first argument as the base
+      # element and the second argument as the selector. Attempts to match the
+      # base element and any of its children. Returns an empty array if no
+      # match is found.
+      #
+      # The selector may be a CSS selector expression (+String+), an expression
+      # with substitution values (+Array+) or an HTML::Selector object.
+      #
+      # For example:
+      #   forms = css_select("form")
+      #   forms.each do |form|
+      #     inputs = css_select(form, "input")
+      #     ...
+      #   end
+      def css_select(*args)
+        # See assert_select to understand what's going on here.
+        arg = args.shift
+
+        if arg.is_a?(HTML::Node)
+          root = arg
+          arg = args.shift
+        elsif arg == nil
+          raise ArgumentError, "First arugment is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
+        elsif @selected
+          matches = []
+          @selected.each do |selected|
+            subset = css_select(selected, HTML::Selector.new(arg.dup, args.dup))
+            subset.each do |match|
+              matches << match unless matches.any? { |m| m.equal?(match) }
+            end
+          end
+
+          return matches
+        else
+          root = response_from_page_or_rjs
+        end
+
+        case arg
+          when String
+            selector = HTML::Selector.new(arg, args)
+          when Array
+            selector = HTML::Selector.new(*arg)
+          when HTML::Selector 
+            selector = arg
+          else raise ArgumentError, "Expecting a selector as the first argument"
+        end
+
+        selector.select(root)  
+      end
+
+      # :call-seq:
+      #   assert_select(selector, equality?, message?)
+      #   assert_select(element, selector, equality?, message?)
+      #
+      # An assertion that selects elements and makes one or more equality tests.
+      #
+      # If the first argument is an element, selects all matching elements
+      # starting from (and including) that element and all its children in
+      # depth-first order.
+      #
+      # If no element if specified, calling #assert_select will select from the
+      # response HTML. Calling #assert_select inside an #assert_select block will
+      # run the assertion for each element selected by the enclosing assertion.
+      #
+      # For example:
+      #   assert_select "ol>li" do |elements|
+      #     elements.each do |element|
+      #       assert_select element, "li"
+      #     end
+      #   end
+      # Or for short:
+      #   assert_select "ol>li" do
+      #     assert_select "li"
+      #   end
+      #
+      # The selector may be a CSS selector expression (+String+), an expression
+      # with substitution values, or an HTML::Selector object.
+      #
+      # === Equality Tests
+      #
+      # The equality test may be one of the following:
+      # * <tt>nil/true</tt> -- Assertion is true if at least one element is
+      #   selected.
+      # * <tt>String</tt> -- Assertion is true if the text value of all
+      #   selected elements equals to the string.
+      # * <tt>Regexp</tt> -- Assertion is true if the text value of all
+      #   selected elements matches the regular expression.
+      # * <tt>false</tt> -- Assertion is true if no element is selected.
+      # * <tt>Integer</tt> -- Assertion is true if exactly that number of
+      #   elements are selected.
+      # * <tt>Range</tt> -- Assertion is true if the number of selected
+      #   elements fit the range.
+      #
+      # To perform more than one equality tests, use a hash the following keys:
+      # * <tt>:text</tt> -- Assertion is true if the text value of each
+      #   selected elements equals to the value (+String+ or +Regexp+).
+      # * <tt>:count</tt> -- Assertion is true if the number of matched elements
+      #   is equal to the value.
+      # * <tt>:minimum</tt> -- Assertion is true if the number of matched
+      #   elements is at least that value.
+      # * <tt>:maximum</tt> -- Assertion is true if the number of matched
+      #   elements is at most that value.
+      #
+      # If the method is called with a block, once all equality tests are
+      # evaluated the block is called with an array of all matched elements.
+      #
+      # === Examples
+      # 
+      #   # At least one form element
+      #   assert_select "form"
+      #
+      #   # Form element includes four input fields
+      #   assert_select "form input", 4
+      #
+      #   # Page title is "Welcome"
+      #   assert_select "title", "Welcome"
+      #
+      #   # Page title is "Welcome" and there is only one title element
+      #   assert_select "title", {:count=>1, :text=>"Welcome"},
+      #       "Wrong title or more than one title element"
+      #
+      #   # Page contains no forms
+      #   assert_select "form", false, "This page must contain no forms"
+      #
+      #   # Test the content and style
+      #   assert_select "body div.header ul.menu"
+      #
+      #   # Use substitution values
+      #   assert_select "ol>li#?", /item-\d+/
+      #
+      #   # All input fields in the form have a name
+      #   assert_select "form input" do
+      #     assert_select "[name=?]", /.+/  # Not empty
+      #   end
+      def assert_select(*args, &block)
+        # Start with optional element followed by mandatory selector.
+        arg = args.shift
+
+        if arg.is_a?(HTML::Node)
+          # First argument is a node (tag or text, but also HTML root),
+          # so we know what we're selecting from.
+          root = arg
+          arg = args.shift
+        elsif arg == nil
+          # This usually happens when passing a node/element that
+          # happens to be nil.
+          raise ArgumentError, "First arugment is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
+        elsif @selected
+          root = HTML::Node.new(nil)
+          root.children.concat @selected
+        else
+          # Otherwise just operate on the response document.
+          root = response_from_page_or_rjs
+        end
+
+        # First or second argument is the selector: string and we pass
+        # all remaining arguments. Array and we pass the argument. Also
+        # accepts selector itself.
+        case arg
+          when String
+            selector = HTML::Selector.new(arg, args)
+          when Array
+            selector = HTML::Selector.new(*arg)
+          when HTML::Selector 
+            selector = arg
+          else raise ArgumentError, "Expecting a selector as the first argument"
+        end
+
+        # Next argument is used for equality tests.
+        equals = {}
+        case arg = args.shift
+          when Hash
+            equals = arg
+          when String, Regexp
+            equals[:text] = arg
+          when Integer
+            equals[:count] = arg
+          when Range
+            equals[:minimum] = arg.begin
+            equals[:maximum] = arg.end
+          when FalseClass
+            equals[:count] = 0
+          when NilClass, TrueClass
+            equals[:minimum] = 1
+          else raise ArgumentError, "I don't understand what you're trying to match"
+        end
+
+        # If we have a text test, by default we're looking for at least one match.
+        # Without this statement text tests pass even if nothing is selected.
+        # Can always override by specifying minimum or count.
+        if equals[:text]
+          equals[:minimum] ||= 1
+        end
+        # If a count is specified, it takes precedence over minimum/maximum.
+        if equals[:count]
+          equals[:minimum] = equals[:maximum] = equals.delete(:count)
+        end
+
+        # Last argument is the message we use if the assertion fails.
+        message = args.shift
+        #- message = "No match made with selector #{selector.inspect}" unless message
+        if args.shift
+          raise ArgumentError, "Not expecting that last argument, you either have too many arguments, or they're the wrong type"
+        end
+
+        matches = selector.select(root)  
+        # Equality test.
+        equals.each do |type, value|
+          case type
+            when :text
+              for match in matches
+                text = ""
+                stack = match.children.reverse
+                while node = stack.pop
+                  if node.tag?
+                    stack.concat node.children.reverse
+                  else
+                    text << node.content
+                  end
+                end
+                text.strip! unless match.name == "pre"
+                if value.is_a?(Regexp)
+                  assert text =~ value, build_message(message, <<EOT, value, text)
+<?> expected but was
+<?>.
+EOT
+                else
+                  assert_equal value.to_s, text, message
+                end
+              end
+            when :html
+              for match in matches
+                html = match.children.map(&:to_s).join
+                html.strip! unless match.name == "pre"
+                if value.is_a?(Regexp)
+                  assert html =~ value, build_message(message, <<EOT, value, html)
+<?> expected but was
+<?>.
+EOT
+                else
+                  assert_equal value.to_s, html, message
+                end
+              end
+            when :minimum
+              assert matches.size >= value, message || "Expecting at least #{value} selected elements, found #{matches.size}"
+            when :maximum
+              assert matches.size <= value, message || "Expecting at most #{value} selected elements, found #{matches.size}"
+            else raise ArgumentError, "I don't support the equality test #{key}"
+          end
+        end
+
+        # If a block is given call that block. Set @selected to allow
+        # nested assert_select, which can be nested several levels deep.
+        if block_given? && !matches.empty?
+          begin
+            in_scope, @selected = @selected, matches
+            yield matches
+          ensure
+            @selected = in_scope
+          end
+        end
+
+        # Returns all matches elements.
+        matches
+      end
+
+      # :call-seq:
+      #   assert_select_rjs(id?) { |elements| ... }
+      #   assert_select_rjs(statement, id?) { |elements| ... }
+      #   assert_select_rjs(:insert, position, id?) { |elements| ... }
+      #
+      # Selects content from the RJS response.
+      #
+      # === Narrowing down
+      #
+      # With no arguments, asserts that one or more elements are updated or
+      # inserted by RJS statements.
+      #
+      # Use the +id+ argument to narrow down the assertion to only statements
+      # that update or insert an element with that identifier.
+      #
+      # Use the first argument to narrow down assertions to only statements
+      # of that type. Possible values are +:replace+, +:replace_html+ and
+      # +:insert_html+.
+      #
+      # Use the argument +:insert+ followed by an insertion position to narrow
+      # down the assertion to only statements that insert elements in that
+      # position. Possible values are +:top+, +:bottom+, +:before+ and +:after+.
+      #
+      # === Using blocks
+      #
+      # Without a block, #assert_select_rjs merely asserts that the response
+      # contains one or more RJS statements that replace or update content.
+      #
+      # With a block, #assert_select_rjs also selects all elements used in
+      # these statements and passes them to the block. Nested assertions are
+      # supported.
+      #
+      # Calling #assert_select_rjs with no arguments and using nested asserts
+      # asserts that the HTML content is returned by one or more RJS statements.
+      # Using #assert_select directly makes the same assertion on the content,
+      # but without distinguishing whether the content is returned in an HTML
+      # or JavaScript.
+      #
+      # === Examples
+      #
+      #   # Updating the element foo.
+      #   assert_select_rjs :update, "foo"
+      #
+      #   # Inserting into the element bar, top position.
+      #   assert_select rjs, :insert, :top, "bar"
+      #
+      #   # Changing the element foo, with an image.
+      #   assert_select_rjs "foo" do
+      #     assert_select "img[src=/images/logo.gif""
+      #   end
+      #
+      #   # RJS inserts or updates a list with four items.
+      #   assert_select_rjs do
+      #     assert_select "ol>li", 4
+      #   end
+      #
+      #   # The same, but shorter.
+      #   assert_select "ol>li", 4
+      def assert_select_rjs(*args, &block)
+        arg = args.shift
+
+        # If the first argument is a symbol, it's the type of RJS statement we're looking
+        # for (update, replace, insertion, etc). Otherwise, we're looking for just about
+        # any RJS statement.
+        if arg.is_a?(Symbol)
+          if arg == :insert
+            arg = args.shift
+            insertion = "insert_#{arg}".to_sym
+            raise ArgumentError, "Unknown RJS insertion type #{arg}" unless RJS_STATEMENTS[insertion]
+            statement = "(#{RJS_STATEMENTS[insertion]})"
+          else
+            raise ArgumentError, "Unknown RJS statement type #{arg}" unless RJS_STATEMENTS[arg]
+            statement = "(#{RJS_STATEMENTS[arg]})"
+          end
+          arg = args.shift
+        else
+          statement = "#{RJS_STATEMENTS[:any]}"
+        end
+
+        # Next argument we're looking for is the element identifier. If missing, we pick
+        # any element.
+        if arg.is_a?(String)
+          id = Regexp.quote(arg)
+          arg = args.shift
+        else
+          id = "[^\"]*"
+        end
+
+        pattern = Regexp.new("#{statement}\\(\"#{id}\", #{RJS_PATTERN_HTML}\\)", Regexp::MULTILINE)
+          
+        # Duplicate the body since the next step involves destroying it.
+        matches = nil
+        @response.body.gsub(pattern) do |match|
+          html = $2
+          # RJS encodes double quotes and line breaks.
+          html.gsub!(/\\"/, "\"")
+          html.gsub!(/\\n/, "\n")
+          matches ||= []
+          matches.concat HTML::Document.new(html).root.children.select { |n| n.tag? }
+          ""
+        end
+        if matches
+          if block_given?
+            begin
+              in_scope, @selected = @selected, matches
+              yield matches
+            ensure
+              @selected = in_scope
+            end
+          end
+          matches
+        else
+          # RJS statement not found.
+          flunk args.shift || "No RJS statement that replaces or inserts HTML content."
+        end
+      end
+
+      # :call-seq:
+      #   assert_select_encoded(element?) { |elements| ... }
+      #
+      # Extracts the content of an element, treats it as encoded HTML and runs
+      # nested assertion on it.
+      #
+      # You typically call this method within another assertion to operate on
+      # all currently selected elements. You can also pass an element or array
+      # of elements.
+      #
+      # The content of each element is un-encoded, and wrapped in the root
+      # element +encoded+. It then calls the block with all un-encoded elements.
+      #
+      # === Example
+      #
+      #   assert_select_feed :rss, 2.0 do
+      #     # Select description element of each feed item. 
+      #     assert_select "channel>item>description" do
+      #       # Run assertions on the encoded elements.
+      #       assert_select_encoded do
+      #         assert_select "p"
+      #       end
+      #     end
+      #   end
+      def assert_select_encoded(element = nil, &block)
+        case element
+          when Array
+            elements = element
+          when HTML::Node
+            elements = [element]
+          when nil
+            unless elements = @selected
+              raise ArgumentError, "First argument is optional, but must be called from a nested assert_select"
+            end
+          else
+            raise ArgumentError, "Argument is optional, and may be node or array of nodes"
+        end
+
+        fix_content = lambda do |node|
+          # Gets around a bug in the Rails 1.1 HTML parser.
+          node.content.gsub(/<!\[CDATA\[(.*)(\]\]>)?/m) { CGI.escapeHTML($1) }
+        end
+
+        selected = elements.map do |element|
+          text = element.children.select{ |c| not c.tag? }.map{ |c| fix_content[c] }.join
+          root = HTML::Document.new(CGI.unescapeHTML("<encoded>#{text}</encoded>")).root
+          css_select(root, "encoded:root", &block)[0]
+        end
+
+        begin
+          old_selected, @selected = @selected, selected
+          assert_select ":root", &block
+        ensure
+          @selected = old_selected
+        end
+      end
+
+      # :call-seq:
+      #   assert_select_email { }
+      #
+      # Extracts the body of an email and runs nested assertions on it.
+      #
+      # You must enable deliveries for this assertion to work, use:
+      #   ActionMailer::Base.perform_deliveries = true
+      #
+      # === Example
+      #
+      # assert_select_email do
+      #   assert_select "h1", "Email alert"
+      # end
+      def assert_select_email(&block)
+        deliveries = ActionMailer::Base.deliveries
+        assert !deliveries.empty?, "No e-mail in delivery list"
+
+        for delivery in deliveries
+          for part in delivery.parts
+            if part["Content-Type"].to_s =~ /^text\/html\W/
+              root = HTML::Document.new(part.body).root
+              assert_select root, ":root", &block
+            end
+          end
+        end
+      end
+
+      protected
+        unless const_defined?(:RJS_STATEMENTS)
+          RJS_STATEMENTS = {
+            :replace      => /Element\.replace/,
+            :replace_html => /Element\.update/
+          }
+          RJS_INSERTIONS = [:top, :bottom, :before, :after]
+          RJS_INSERTIONS.each do |insertion|
+            RJS_STATEMENTS["insert_#{insertion}".to_sym] = Regexp.new(Regexp.quote("new Insertion.#{insertion.to_s.camelize}"))
+          end
+          RJS_STATEMENTS[:any] = Regexp.new("(#{RJS_STATEMENTS.values.join('|')})")
+          RJS_STATEMENTS[:insert_html] = Regexp.new(RJS_INSERTIONS.collect do |insertion|
+            Regexp.quote("new Insertion.#{insertion.to_s.camelize}")
+          end.join('|'))
+          RJS_PATTERN_HTML = /"((\\"|[^"])*)"/
+          RJS_PATTERN_EVERYTHING = Regexp.new("#{RJS_STATEMENTS[:any]}\\(\"([^\"]*)\", #{RJS_PATTERN_HTML}\\)",
+                                              Regexp::MULTILINE)
+        end
+
+        # #assert_select and #css_select call this to obtain the content in the HTML
+        # page, or from all the RJS statements, depending on the type of response.
+        def response_from_page_or_rjs()
+          content_type = @response.headers["Content-Type"]
+          if content_type && content_type =~ /text\/javascript/
+            body = @response.body.dup
+            root = HTML::Node.new(nil)
+            while true
+              next if body.sub!(RJS_PATTERN_EVERYTHING) do |match|
+                # RJS encodes double quotes and line breaks.
+                html = $3
+                html.gsub!(/\\"/, "\"")
+                html.gsub!(/\\n/, "\n")
+                matches = HTML::Document.new(html).root.children.select { |n| n.tag? }
+                root.children.concat matches
+                ""
+              end
+              break
+            end
+            root
+          else
+            html_document.root
+          end
+        end
+    end
+  end
+end
+
+Test::Unit::TestCase.send :include, ActionController::Assertions::SelectorAssertions
\ No newline at end of file