base on Extracting DomAssertions and SelectorAssertions from ActionView. # Rails::Dom::Testing This gem is responsible for comparing HTML doms and asserting that DOM elements are present in Rails applications. Doms are compared via `assert_dom_equal` and `assert_dom_not_equal`. Elements are asserted via `assert_dom`, `assert_dom_encoded`, `assert_dom_email` and a subset of the dom can be selected with `css_select`. The gem is developed for Rails 4.2 and above, and will not work on previous versions. ## Usage ### Dom Assertions ```ruby assert_dom_equal '<h1>Lingua França</h1>', '<h1>Lingua França</h1>' assert_dom_not_equal '<h1>Portuguese</h1>', '<h1>Danish</h1>' ``` ### Selector Assertions ```ruby # implicitly selects from the document_root_element css_select '.hello' # => Nokogiri::XML::NodeSet of elements with hello class # select from a supplied node. assert_dom asserts elements exist. assert_dom document_root_element.at('.hello'), '.goodbye' # select from a supplied node. assert_not_dom asserts elements do not exist. assert_not_dom document_root_element.at('.hello'), '.goodbye' # elements in CDATA encoded sections can also be selected assert_dom_encoded '#out-of-your-element' # assert elements within an html email exists assert_dom_email '#you-got-mail' ``` The documentation in [selector_assertions.rb](https://github.com/rails/rails-dom-testing/blob/master/lib/rails/dom/testing/assertions/selector_assertions.rb) goes into a lot more detail of how selector assertions can be used. ### HTML versions By default, assertions will use Nokogiri's HTML4 parser. If `Rails::Dom::Testing.default_html_version` is set to `:html5`, then the assertions will use Nokogiri's HTML5 parser. (If the HTML5 parser is not available on your platform, then a `NotImplementedError` will be raised.) When testing in a Rails application, the parser default can also be set by setting `Rails.application.config.dom_testing_default_html_version`. Some assertions support an `html_version:` keyword argument which can override the default for that assertion. For example: ``` ruby # compare DOMs built with the HTML5 parser assert_dom_equal(expected, actual, html_version: :html5) # compare DOMs built with the HTML4 parser assert_dom_not_equal(expected, actual, html_version: :html4) ``` Please see documentation for individual assertions for more details. ## Installation Add this line to your application's Gemfile: gem 'rails-dom-testing' And then execute: $ bundle Or install it yourself as: $ gem install rails-dom-testing ## Read more Under the hood the doms are parsed with Nokogiri, and you'll generally be working with these two classes: - [`Nokogiri::XML::Node`](http://www.rubydoc.info/github/sparklemotion/nokogiri/Nokogiri/XML/Node) - [`Nokogiri::XML::NodeSet`](http://www.rubydoc.info/github/sparklemotion/nokogiri/Nokogiri/XML/NodeSet) Read more about Nokogiri: - [Nokogiri](http://nokogiri.org) ## Contributing to Rails::Dom::Testing Rails::Dom::Testing is work of many contributors. You're encouraged to submit pull requests, propose features and discuss issues. See [CONTRIBUTING](CONTRIBUTING.md). ## License Rails::Dom::Testing is released under the [MIT License](MIT-LICENSE). ", Assign "at most 3 tags" to the expected json: {"id":"10285","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"