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Diffstat (limited to 'actionview/lib/action_view/testing/assertions/selector.rb')
-rw-r--r-- | actionview/lib/action_view/testing/assertions/selector.rb | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/actionview/lib/action_view/testing/assertions/selector.rb b/actionview/lib/action_view/testing/assertions/selector.rb new file mode 100644 index 0000000000..bc8f40a245 --- /dev/null +++ b/actionview/lib/action_view/testing/assertions/selector.rb @@ -0,0 +1,465 @@ +require 'active_support/core_ext/object/inclusion' + +#-- +# Copyright (c) 2006 Assaf Arkin (http://labnotes.org) +# Under MIT and/or CC By license. +#++ + +module ActionView + 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. + 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 + # Nokogiri::XML::NodeSet if no match is found. + # + # If called with two arguments, uses the first argument as the root + # element and the second argument as the selector. Attempts to match the + # root element and any of its children. + # Returns an empty Nokogiri::XML::NodeSet if no match is found. + # + # The selector may be a CSS selector expression (String). + # + # # 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) + raise ArgumentError, "you at least need a selector" if args.empty? + + if args.first.is_a?(String) + root, selector = response_from_page, args.first + else + root, selector = args.shift, args.first + end + + root.css(selector).tap do |matches| + if matches.empty? && root.matches?(selector) + return Nokogiri::XML::NodeSet.new(root.document, [root]) + end + end + 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 is 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) or an expression + # with substitution values (Array). + # Substitution uses a custom pseudo class match. Pass in whatever attribute you want to match (enclosed in quotes) and a ? for the substitution. + # + # assert_select "div:match('id', ?)", /\d+/ + # + # === 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. + # + # # 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:match('id', ?)", /item-\d+/ + # + # # All input fields in the form have a name + # assert_select "form input" do + # assert_select ":match('name', ?)", /.+/ # Not empty + # end + def assert_select(*args, &block) + @selected ||= nil + + selector = HTMLSelector.new(@selected, response_from_page, args) + + matches = selector.select + assert_size_match!(matches.size, selector.comparisons, selector.source, selector.message) + + # Set @selected to allow nested assert_select. + # 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 + + 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. + # + # # Selects all bold tags from within the title of an Atom feed's entries (perhaps to nab a section name prefix) + # assert_select "feed[xmlns='http://www.w3.org/2005/Atom']" 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 "rss[version=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 Nokogiri::XML::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 + + content = elements.map do |elem| + elem.children.select(&:cdata?).map(&:content) + end.join + selected = Loofah.fragment(content) + + begin + old_selected, @selected = @selected, selected + if content.empty? + yield selected + else + assert_select ":root", &block + end + 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 + # + # 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" + + deliveries.each do |delivery| + (delivery.parts.empty? ? [delivery] : delivery.parts).each do |part| + if part["Content-Type"].to_s =~ /^text\/html\W/ + root = Loofah.fragment(part.body.to_s) + assert_select root, ":root", &block + end + end + end + end + + protected + # +equals+ must contain :minimum, :maximum and :count keys + def assert_size_match!(size, equals, css_selector, message = nil) + min, max, count = equals[:minimum], equals[:maximum], equals[:count] + + message ||= %(Expected #{count_description(min, max, count)} matching "#{css_selector}", found #{size}.) + if count + assert_equal size, count, message + else + assert_operator size, :>=, min, message if min + assert_operator size, :<=, max, message if max + end + end + + # +html_document+ is used in testing/integration.rb + def html_document + @html_document ||= if @response.content_type =~ /xml$/ + Loofah.xml_document(@response.body) + else + Loofah.document(@response.body) + end + end + + def response_from_page + html_document.root + end + + class HTMLSelector #:nodoc: + attr_accessor :root, :css_selector, :comparisons, :message + + alias :source :css_selector + + def initialize(selected, page, args) + @selected, @page = selected, page + + # Start with optional element followed by mandatory selector. + @root = determine_root_from(args.first) + + # First or second argument is the selector + selector = @css_selector_is_second_argument ? args.shift(2).last : args.shift + @css_selector = selector_from(selector, args) + + # Next argument is used for equality tests. + @comparisons = comparisons_from(args.shift) + + # Last argument is the message we use if the assertion fails. + @message = args.shift + + if args.shift + raise ArgumentError, "Not expecting that last argument, you either have too many arguments, or they're the wrong type" + end + end + + def select + filter root.css(css_selector, context) + end + + def filter(matches) + match_with = comparisons[:text] || comparisons[:html] + return matches if matches.empty? || !match_with + + content_mismatch = nil + text_matches = comparisons.has_key?(:text) + + remaining = matches.reject do |match| + # Preserve markup with to_s for html elements + content = text_matches ? match.text : match.children.to_s + + content.strip! unless NO_STRIP.include?(match.name) + content.sub!(/\A\n/, '') if text_matches && match.name == "textarea" + + unless match_with.is_a?(Regexp) ? (content =~ match_with) : (content == match_with.to_s) + content_mismatch ||= sprintf("<%s> expected but was\n<%s>.", match_with, content) + true + end + end + + # Expecting foo found bar element only if found zero, not if + # found one but expecting two. + self.message ||= content_mismatch if remaining.empty? + + Nokogiri::XML::NodeSet.new(matches.document, remaining) + end + + def determine_root_from(root_or_selector) + @css_selector_is_second_argument = false + if root_or_selector == 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 root_or_selector.is_a?(Nokogiri::XML::Node) || root_or_selector.is_a?(Nokogiri::XML::NodeSet) + # First argument is a node (tag or text, but also HTML root), + # so we know what we're selecting from. + @css_selector_is_second_argument = true + + root_or_selector + elsif @selected + if @selected.is_a?(Array) + doc = @selected.empty? ? @page.document : @selected[0].document + @selected = Nokogiri::XML::NodeSet.new(doc, @selected) + end + @selected + else + @page + end + end + + def selector_from(selector, substitution_values) + unless selector.is_a? String + raise ArgumentError, "Expecting a selector as the first argument" + end + context.substitute!(selector, substitution_values) + end + + def comparisons_from(comparator) + comparisons = {} + case comparator + when Hash + comparisons = comparator + when String, Regexp + comparisons[:text] = comparator + when Integer + comparisons[:count] = comparator + when Range + comparisons[:minimum] = comparator.begin + comparisons[:maximum] = comparator.end + when FalseClass + comparisons[:count] = 0 + when NilClass, TrueClass + comparisons[: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 comparisons[:count] + comparisons[:minimum] = comparisons[:maximum] = comparisons[:count] + else + comparisons[:minimum] ||= 1 + end + comparisons + end + + def context + @context ||= SubstitutionContext.new + end + + class SubstitutionContext + def initialize(substitute = '?') + @substitute = substitute + @regexes = [] + end + + def add_regex(regex) + # Nokogiri doesn't like arbitrary values without quotes, hence inspect. + return regex.inspect unless regex.is_a?(Regexp) + @regexes.push(regex) + last_id.to_s # avoid implicit conversions of Fixnum to String + end + + def last_id + @regexes.count - 1 + end + + def match(matches, attribute, id) + matches.find_all { |node| node[attribute] =~ @regexes[id] } + end + + def substitute!(selector, values) + while !values.empty? && selector.index(@substitute) + selector.sub!(@substitute, add_regex(values.shift)) + end + selector + end + end + end + end + end +end |