add :download filter to :link selector

lib/capybara/selector.rb

@@ -112,6 +112,15 @@ Capybara.add_selector(:link) do
     href.is_a?(Regexp) ? node[:href].match(href) : true
   end
 
+  expression_filter(:download, valid_values: [true, false, String]) do |expr, download|
+    mod = case download
+    when true then XPath.attr(:download)
+    when false then !XPath.attr(:download)
+    when String then XPath.attr(:download) == download
+    end
+    expr[mod]
+  end
+
   describe do |**options|
     desc = +""
     desc << " with href #{options[:href].inspect}" if options[:href]

lib/capybara/selector/filters/base.rb

@@ -49,7 +49,8 @@ module Capybara
         end
 
         def valid_value?(value)
-          !@options.key?(:valid_values) || Array(@options[:valid_values]).include?(value)
+          return true unless @options.key?(:valid_values)
+          Array(@options[:valid_values]).any? { |valid| valid === value } # rubocop:disable Style/CaseEquality
         end
       end
     end

lib/capybara/spec/session/find_link_spec.rb

@@ -49,4 +49,22 @@ Capybara::SpecHelper.spec '#find_link' do
       expect(@session.find_link(href: '#anchor').text).to eq "Normal Anchor"
     end
   end
+
+  context "download filter" do
+    it "finds a download link" do
+      expect(@session.find_link("Download Me", download: true).text).to eq "Download Me"
+    end
+
+    it "doesn't find a download link if download is false" do
+      expect { @session.find_link("Download Me", download: false) }.to raise_error Capybara::ElementNotFound
+    end
+
+    it "finds a renaming download link" do
+      expect(@session.find_link(download: "other.csv").text).to eq "Download Other"
+    end
+
+    it "raises if passed an invalid value" do
+      expect { @session.find_link(download: 37) }.to raise_error ArgumentError
+    end
+  end
 end

lib/capybara/spec/views/with_html.erb

@@ -175,3 +175,4 @@ banana</textarea>
 </div>
 
 <a href="/download.csv" download>Download Me</a>
+<a href="/download.csv" download="other.csv">Download Other</a>

spec/selenium_spec_chrome.rb

@@ -15,9 +15,7 @@ Capybara.register_driver :selenium_chrome do |app|
   driver = Capybara::Selenium::Driver.new(app, browser: :chrome)
   # TODO: Fix this when selenium with `download_path =` support is released
   bridge = driver.browser.send(:bridge)
-  params = { 'cmd' =>'Page.setDownloadBehavior',
-             "params" => {"behavior" => 'allow', 'downloadPath' => Capybara.save_path }
-           }
+  params = { cmd: 'Page.setDownloadBehavior', params: { behavior: 'allow', downloadPath: Capybara.save_path } }
   command = +'/session/:session_id/chromium/send_command'
   command[':session_id'] = bridge.session_id
   bridge.http.call(:post, command, params)
@@ -33,9 +31,7 @@ Capybara.register_driver :selenium_chrome_headless do |app|
 
   # TODO: Fix this when selenium with `download_path =` support is released
   bridge = driver.browser.send(:bridge)
-  params = { 'cmd' =>'Page.setDownloadBehavior',
-             "params" => {"behavior" => 'allow', 'downloadPath' => Capybara.save_path }
-           }
+  params = { cmd: 'Page.setDownloadBehavior', params: { behavior: 'allow', downloadPath: Capybara.save_path } }
   command = +'/session/:session_id/chromium/send_command'
   command[':session_id'] = bridge.session_id
   bridge.http.call(:post, command, params)
@@ -43,7 +39,6 @@ Capybara.register_driver :selenium_chrome_headless do |app|
   driver
 end
 
-
 Capybara.register_driver :selenium_chrome_clear_storage do |app|
   chrome_options = {
     browser: :chrome,