aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/action_dispatch/testing/assertions/selector.rb
blob: afbd86915260827a641e5fa8573dc280dee6e269 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
require 'action_controller/vendor/html-scanner'
require 'active_support/core_ext/object/inclusion'

#--
# Copyright (c) 2006 Assaf Arkin (http://labnotes.org)
# Under MIT and/or CC By license.
#++

module ActionDispatch
  module Assertions
    NO_STRIP = %w{pre script style textarea}

    # 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:
    #
    # * +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 to learn how to use selectors.
    module SelectorAssertions
      # 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
      #
      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 argument is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
        elsif defined?(@selected) && @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
        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

      # 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:
      # * <tt>true</tt> - Assertion is true if at least one element selected.
      # * <tt>false</tt> - Assertion is true if no element selected.
      # * <tt>String/Regexp</tt> - Assertion is true if the text value of at least
      #   one element matches the string or regular expression.
      # * <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.
      # 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:
      # * <tt>:text</tt> - Narrow the selection to elements that have this text
      #   value (string or regexp).
      # * <tt>:html</tt> - Narrow the selection to elements that have this HTML
      #   content (string or regexp).
      # * <tt>:count</tt> - Assertion is true if the number of selected elements
      #   is equal to this value.
      # * <tt>:minimum</tt> - Assertion is true if the number of selected
      #   elements is at least this value.
      # * <tt>:maximum</tt> - 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
      def assert_select(*args, &block)
        # Start with optional element followed by mandatory selector.
        arg = args.shift
        @selected ||= nil

        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 argument 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
        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

        # By default we're looking for at least one match.
        if equals[:count]
          equals[:minimum] = equals[:maximum] = equals[:count]
        else
          equals[:minimum] = 1 unless equals[:minimum]
        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)
        # If text/html, narrow down to those elements that match it.
        content_mismatch = nil
        if match_with = equals[:text]
          matches.delete_if do |match|
            text = ""
            stack = match.children.reverse
            while node = stack.pop
              if node.tag?
                stack.concat node.children.reverse
              else
                content = node.content
                text << content
              end
            end
            text.strip! unless NO_STRIP.include?(match.name)
            text.sub!(/\A\n/, '') if match.name == "textarea"
            unless match_with.is_a?(Regexp) ? (text =~ match_with) : (text == match_with.to_s)
              content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, text)
              true
            end
          end
        elsif match_with = equals[:html]
          matches.delete_if do |match|
            html = match.children.map(&:to_s).join
            html.strip! unless NO_STRIP.include?(match.name)
            unless match_with.is_a?(Regexp) ? (html =~ match_with) : (html == match_with.to_s)
              content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, html)
              true
            end
          end
        end
        # Expecting foo found bar element only if found zero, not if
        # found one but expecting two.
        message ||= content_mismatch if matches.empty?
        # Test minimum/maximum occurrence.
        min, max, count = equals[:minimum], equals[:maximum], equals[:count]
        message = message || %(Expected #{count_description(min, max, count)} matching "#{selector.to_s}", found #{matches.size}.)
        if count
          assert matches.size == count, message
        else
          assert matches.size >= min, message if min
          assert matches.size <= max, message if max
        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

      def count_description(min, max, count) #:nodoc:
        pluralize = lambda {|word, quantity| word << (quantity == 1 ? '' : 's')}

        if min && max && (max != min)
          "between #{min} and #{max} elements"
        elsif min && max && max == min && count
          "exactly #{count} #{pluralize['element', min]}"
        elsif min && !(min == 1 && max == 1)
          "at least #{min} #{pluralize['element', min]}"
        elsif max
          "at most #{max} #{pluralize['element', max]}"
        end
      end

      # 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
      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) { Rack::Utils.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

      # 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
      #
      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.empty? ? [delivery] : delivery.parts)
            if part["Content-Type"].to_s =~ /^text\/html\W/
              root = HTML::Document.new(part.body.to_s).root
              assert_select root, ":root", &block
            end
          end
        end
      end

      protected
        # +assert_select+ and +css_select+ call this to obtain the content in the HTML page.
        def response_from_page
          html_document.root
        end
    end
  end
end