Adds the assert_select method for use in Rails functional test cases, which can be used 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:

Also see HTML::Selector to learn how to use selectors.

Methods
Constants
RJS_PATTERN_HTML = "\"((\\\\\"|[^\"])*)\""
RJS_ANY_ID = "\"([^\"])*\""
RJS_STATEMENTS = { :chained_replace => "\\$\\(#{RJS_ANY_ID}\\)\\.replace\\(#{RJS_PATTERN_HTML}\\)", :chained_replace_html => "\\$\\(#{RJS_ANY_ID}\\)\\.update\\(#{RJS_PATTERN_HTML}\\)", :replace_html => "Element\\.update\\(#{RJS_ANY_ID}, #{RJS_PATTERN_HTML}\\)", :replace => "Element\\.replace\\(#{RJS_ANY_ID}, #{RJS_PATTERN_HTML}\\)"
RJS_INSERTIONS = ["top", "bottom", "before", "after"]
RJS_PATTERN_UNICODE_ESCAPED_CHAR = /\\u([0-9a-zA-Z]{4})/
Public Class methods
new(*args)

[ show source ]

    # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 28
28:       def initialize(*args)
29:         super
30:         @selected = nil
31:       end
Public Instance methods
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 selects from the response HTML unless assert_select is called from within an assert_select block.

When called with a block assert_select passes an array of selected elements to the block. Calling assert_select from the block, with no element specified, runs the assertion on the complete set of elements selected by the enclosing assertion. Alternatively the array may be iterated through so that assert_select can be called separately for each element.

Example

If the response contains two ordered lists, each with four list elements then: 

  assert_select "ol" do |elements|
    elements.each do |element|
      assert_select element, "li", 4
    end
  end

will pass, as will: 

  assert_select "ol" do
    assert_select "li", 8
  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:

  • true - Assertion is true if at least one element selected.
  • false - Assertion is true if no element selected.
  • String/Regexp - Assertion is true if the text value of at least one element matches the string or regular expression.
  • Integer - Assertion is true if exactly that number of elements are selected.
  • Range - Assertion is true if the number of selected elements fit the range.

If no equality test specified, the assertion is true if at least one element selected.

To perform more than one equality tests, use a hash with the following keys:

  • :text - Narrow the selection to elements that have this text value (string or regexp).
  • :html - Narrow the selection to elements that have this HTML content (string or regexp).
  • :count - Assertion is true if the number of selected elements is equal to this value.
  • :minimum - Assertion is true if the number of selected elements is at least this value.
  • :maximum - Assertion is true if the number of selected elements is at most this 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

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 201
201:       def assert_select(*args, &block)
202:         # Start with optional element followed by mandatory selector.
203:         arg = args.shift
204: 
205:         if arg.is_a?(HTML::Node)
206:           # First argument is a node (tag or text, but also HTML root),
207:           # so we know what we're selecting from.
208:           root = arg
209:           arg = args.shift
210:         elsif arg == nil
211:           # This usually happens when passing a node/element that
212:           # happens to be nil.
213:           raise ArgumentError, "First argument is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
214:         elsif @selected
215:           root = HTML::Node.new(nil)
216:           root.children.concat @selected
217:         else
218:           # Otherwise just operate on the response document.
219:           root = response_from_page_or_rjs
220:         end
221: 
222:         # First or second argument is the selector: string and we pass
223:         # all remaining arguments. Array and we pass the argument. Also
224:         # accepts selector itself.
225:         case arg
226:           when String
227:             selector = HTML::Selector.new(arg, args)
228:           when Array
229:             selector = HTML::Selector.new(*arg)
230:           when HTML::Selector
231:             selector = arg
232:           else raise ArgumentError, "Expecting a selector as the first argument"
233:         end
234: 
235:         # Next argument is used for equality tests.
236:         equals = {}
237:         case arg = args.shift
238:           when Hash
239:             equals = arg
240:           when String, Regexp
241:             equals[:text] = arg
242:           when Integer
243:             equals[:count] = arg
244:           when Range
245:             equals[:minimum] = arg.begin
246:             equals[:maximum] = arg.end
247:           when FalseClass
248:             equals[:count] = 0
249:           when NilClass, TrueClass
250:             equals[:minimum] = 1
251:           else raise ArgumentError, "I don't understand what you're trying to match"
252:         end
253: 
254:         # By default we're looking for at least one match.
255:         if equals[:count]
256:           equals[:minimum] = equals[:maximum] = equals[:count]
257:         else
258:           equals[:minimum] = 1 unless equals[:minimum]
259:         end
260: 
261:         # Last argument is the message we use if the assertion fails.
262:         message = args.shift
263:         #- message = "No match made with selector #{selector.inspect}" unless message
264:         if args.shift
265:           raise ArgumentError, "Not expecting that last argument, you either have too many arguments, or they're the wrong type"
266:         end
267: 
268:         matches = selector.select(root)
269:         # If text/html, narrow down to those elements that match it.
270:         content_mismatch = nil
271:         if match_with = equals[:text]
272:           matches.delete_if do |match|
273:             text = ""
274:             text.force_encoding(match_with.encoding) if text.respond_to?(:force_encoding)
275:             stack = match.children.reverse
276:             while node = stack.pop
277:               if node.tag?
278:                 stack.concat node.children.reverse
279:               else
280:                 content = node.content
281:                 content.force_encoding(match_with.encoding) if content.respond_to?(:force_encoding)
282:                 text << content
283:               end
284:             end
285:             text.strip! unless NO_STRIP.include?(match.name)
286:             unless match_with.is_a?(Regexp) ? (text =~ match_with) : (text == match_with.to_s)
287:               content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, text)
288:               true
289:             end
290:           end
291:         elsif match_with = equals[:html]
292:           matches.delete_if do |match|
293:             html = match.children.map(&:to_s).join
294:             html.strip! unless NO_STRIP.include?(match.name)
295:             unless match_with.is_a?(Regexp) ? (html =~ match_with) : (html == match_with.to_s)
296:               content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, html)
297:               true
298:             end
299:           end
300:         end
301:         # Expecting foo found bar element only if found zero, not if
302:         # found one but expecting two.
303:         message ||= content_mismatch if matches.empty?
304:         # Test minimum/maximum occurrence.
305:         min, max = equals[:minimum], equals[:maximum]
306:         message = message || %(Expected #{count_description(min, max)} matching "#{selector.to_s}", found #{matches.size}.)
307:         assert matches.size >= min, message if min
308:         assert matches.size <= max, message if max
309: 
310:         # If a block is given call that block. Set @selected to allow
311:         # nested assert_select, which can be nested several levels deep.
312:         if block_given? && !matches.empty?
313:           begin
314:             in_scope, @selected = @selected, matches
315:             yield matches
316:           ensure
317:             @selected = in_scope
318:           end
319:         end
320: 
321:         # Returns all matches elements.
322:         matches
323:       end
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

Examples

 assert_select_email do
   assert_select "h1", "Email alert"
 end

 assert_select_email do
   items = assert_select "ol>li"
   items.each do
      # Work with items here...
   end
 end

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 563
563:       def assert_select_email(&block)
564:         deliveries = ActionMailer::Base.deliveries
565:         assert !deliveries.empty?, "No e-mail in delivery list"
566: 
567:         for delivery in deliveries
568:           for part in delivery.parts
569:             if part["Content-Type"].to_s =~ /^text\/html\W/
570:               root = HTML::Document.new(part.body).root
571:               assert_select root, ":root", &block
572:             end
573:           end
574:         end
575:       end
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.

Examples

  # Selects all bold tags from within the title of an ATOM feed's entries (perhaps to nab a section name prefix)
  assert_select_feed :atom, 1.0 do
    # Select each entry item and then the title item
    assert_select "entry>title" do
      # Run assertions on the encoded title elements
      assert_select_encoded do
        assert_select "b"
      end
    end
  end

  # Selects all paragraph tags from within the description of an RSS feed
  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

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 509
509:       def assert_select_encoded(element = nil, &block)
510:         case element
511:           when Array
512:             elements = element
513:           when HTML::Node
514:             elements = [element]
515:           when nil
516:             unless elements = @selected
517:               raise ArgumentError, "First argument is optional, but must be called from a nested assert_select"
518:             end
519:           else
520:             raise ArgumentError, "Argument is optional, and may be node or array of nodes"
521:         end
522: 
523:         fix_content = lambda do |node|
524:           # Gets around a bug in the Rails 1.1 HTML parser.
525:           node.content.gsub(/<!\[CDATA\[(.*)(\]\]>)?/m) { CGI.escapeHTML($1) }
526:         end
527: 
528:         selected = elements.map do |element|
529:           text = element.children.select{ |c| not c.tag? }.map{ |c| fix_content[c] }.join
530:           root = HTML::Document.new(CGI.unescapeHTML("<encoded>#{text}</encoded>")).root
531:           css_select(root, "encoded:root", &block)[0]
532:         end
533: 
534:         begin
535:           old_selected, @selected = @selected, selected
536:           assert_select ":root", &block
537:         ensure
538:           @selected = old_selected
539:         end
540:       end
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, :show, :hide, :toggle, :remove 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 the :remove statement, you will be able to pass a block, but it will be ignored as there is no HTML passed for this statement.

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

  # Replacing the element foo.
  # page.replace 'foo', ...
  assert_select_rjs :replace, "foo"

  # Replacing with the chained RJS proxy.
  # page[:foo].replace ...
  assert_select_rjs :chained_replace, 'foo'

  # Inserting into the element bar, top position.
  assert_select_rjs :insert, :top, "bar"

  # Remove the element bar
  assert_select_rjs :remove, "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

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 408
408:       def assert_select_rjs(*args, &block)
409:         rjs_type = args.first.is_a?(Symbol) ? args.shift : nil
410:         id       = args.first.is_a?(String) ? args.shift : nil
411: 
412:         # If the first argument is a symbol, it's the type of RJS statement we're looking
413:         # for (update, replace, insertion, etc). Otherwise, we're looking for just about
414:         # any RJS statement.
415:         if rjs_type
416:           if rjs_type == :insert
417:             position  = args.shift
418:             id = args.shift
419:             insertion = "insert_#{position}".to_sym
420:             raise ArgumentError, "Unknown RJS insertion type #{position}" unless RJS_STATEMENTS[insertion]
421:             statement = "(#{RJS_STATEMENTS[insertion]})"
422:           else
423:             raise ArgumentError, "Unknown RJS statement type #{rjs_type}" unless RJS_STATEMENTS[rjs_type]
424:             statement = "(#{RJS_STATEMENTS[rjs_type]})"
425:           end
426:         else
427:           statement = "#{RJS_STATEMENTS[:any]}"
428:         end
429: 
430:         # Next argument we're looking for is the element identifier. If missing, we pick
431:         # any element, otherwise we replace it in the statement.
432:         pattern = Regexp.new(
433:           id ? statement.gsub(RJS_ANY_ID, "\"#{id}\"") : statement
434:         )
435: 
436:         # Duplicate the body since the next step involves destroying it.
437:         matches = nil
438:         case rjs_type
439:           when :remove, :show, :hide, :toggle
440:             matches = @response.body.match(pattern)
441:           else
442:             @response.body.gsub(pattern) do |match|
443:               html = unescape_rjs(match)
444:               matches ||= []
445:               matches.concat HTML::Document.new(html).root.children.select { |n| n.tag? }
446:               ""
447:             end
448:         end
449: 
450:         if matches
451:           assert_block("") { true } # to count the assertion
452:           if block_given? && !([:remove, :show, :hide, :toggle].include? rjs_type)
453:             begin
454:               in_scope, @selected = @selected, matches
455:               yield matches
456:             ensure
457:               @selected = in_scope
458:             end
459:           end
460:           matches
461:         else
462:           # RJS statement not found.
463:           case rjs_type
464:             when :remove, :show, :hide, :toggle
465:               flunk_message = "No RJS statement that #{rjs_type.to_s}s '#{id}' was rendered."
466:             else
467:               flunk_message = "No RJS statement that replaces or inserts HTML content."
468:           end
469:           flunk args.shift || flunk_message
470:         end
471:       end
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.

Examples

  # Selects all div tags
  divs = css_select("div")

  # Selects all paragraph tags and does something interesting
  pars = css_select("p")
  pars.each do |par|
    # Do something fun with paragraphs here...
  end

  # Selects all list items in unordered lists
  items = css_select("ul>li")

  # Selects all form tags and then all inputs inside the form
  forms = css_select("form")
  forms.each do |form|
    inputs = css_select(form, "input")
    ...
  end

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 71
 71:       def css_select(*args)
 72:         # See assert_select to understand what's going on here.
 73:         arg = args.shift
 74: 
 75:         if arg.is_a?(HTML::Node)
 76:           root = arg
 77:           arg = args.shift
 78:         elsif arg == nil
 79:           raise ArgumentError, "First argument is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
 80:         elsif @selected
 81:           matches = []
 82: 
 83:           @selected.each do |selected|
 84:             subset = css_select(selected, HTML::Selector.new(arg.dup, args.dup))
 85:             subset.each do |match|
 86:               matches << match unless matches.any? { |m| m.equal?(match) }
 87:             end
 88:           end
 89: 
 90:           return matches
 91:         else
 92:           root = response_from_page_or_rjs
 93:         end
 94: 
 95:         case arg
 96:           when String
 97:             selector = HTML::Selector.new(arg, args)
 98:           when Array
 99:             selector = HTML::Selector.new(*arg)
100:           when HTML::Selector
101:             selector = arg
102:           else raise ArgumentError, "Expecting a selector as the first argument"
103:         end
104: 
105:         selector.select(root)
106:       end
Protected Instance methods
response_from_page_or_rjs()

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.

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 601
601:         def response_from_page_or_rjs()
602:           content_type = @response.content_type
603: 
604:           if content_type && Mime::JS =~ content_type
605:             body = @response.body.dup
606:             root = HTML::Node.new(nil)
607: 
608:             while true
609:               next if body.sub!(RJS_STATEMENTS[:any]) do |match|
610:                 html = unescape_rjs(match)
611:                 matches = HTML::Document.new(html).root.children.select { |n| n.tag? }
612:                 root.children.concat matches
613:                 ""
614:               end
615:               break
616:             end
617: 
618:             root
619:           else
620:             html_document.root
621:           end
622:         end
unescape_rjs(rjs_string)

Unescapes a RJS string.

[ show source ]

     # File actionpack/lib/action_controller/assertions/selector_assertions.rb, line 625
625:         def unescape_rjs(rjs_string)
626:           # RJS encodes double quotes and line breaks.
627:           unescaped= rjs_string.gsub('\"', '"')
628:           unescaped.gsub!(/\\\//, '/')
629:           unescaped.gsub!('\n', "\n")
630:           unescaped.gsub!('\076', '>')
631:           unescaped.gsub!('\074', '<')
632:           # RJS encodes non-ascii characters.
633:           unescaped.gsub!(RJS_PATTERN_UNICODE_ESCAPED_CHAR) {|u| [$1.hex].pack('U*')}
634:           unescaped
635:         end