fix: gracefully handle unloaded iframes (#315)

packages/axe-core-api/e2e/selenium/spec/api_spec.rb

@@ -66,11 +66,16 @@ def recursive_compact(thing)
   end
 end
 
+
+def get_check_by_id(check_list, id)
+  return check_list.find { |check| check.id == id }
+end
+
 describe "Crashes" do
   it "throws if axe errors out on the top window" do
     $driver.get fixture "/crash.html"
     with_js($axe_post_43x + $crasher_js) {
-      expect { run_axe }.to raise_error /Boom!/ 
+      expect { run_axe }.to raise_error /Boom!/
     }
   end
 
@@ -95,6 +100,26 @@ def recursive_compact(thing)
 end
 
 describe "frame tests" do
+  it "works on pages with unloaded frames" do
+    $driver.get fixture "/lazy-loaded-iframe.html"
+    title = $driver.title
+    res = run_axe
+    expect(title).not_to eq "Error"
+    frame_tested = get_check_by_id res.results.incomplete, :'frame-tested'
+    expect(frame_tested.nodes.length).to be 1
+    expect(frame_tested.nodes[0].target).to contain_exactly(
+      "#ifr-lazy",
+      "#lazy-iframe"
+    )
+
+    label = get_check_by_id res.results.violations, :label
+    expect(label.nodes.length).to be 1
+    expect(label.nodes[0].target).to contain_exactly(
+      "#ifr-lazy",
+      "#lazy-baz",
+      "input"
+    )
+  end
   it "injects into nested iframes", :fo => true do
     $driver.get fixture "/nested-iframes.html"
     res = run_axe
@@ -253,6 +278,15 @@ def recursive_compact(thing)
 
     expect(res.results.url).to eq(fixture "/index.html")
   end
+
+  it "keeps selenium page-load to user-set" do
+    my_page_load = 3.0
+    $driver.manage.timeouts.page_load = my_page_load
+    $driver.get fixture "/index.html"
+    res = run_axe
+
+    expect($driver.manage.timeouts.page_load).to be my_page_load
+  end
 end
 
 describe "axe.finishRun" do

packages/axe-core-api/lib/axe/api/run.rb

@@ -32,27 +32,34 @@ def call(page)
       end
 
       def analyze_post_43x(page, lib)
-        @original_window = window_handle page
-        partial_results = run_partial_recursive(page, @context, lib, true)
-        throw partial_results if partial_results.respond_to?("key?") and partial_results.key?("errorMessage")
-        results = within_about_blank_context(page) { |page|
-          partial_res_str = partial_results.to_json
-          size_limit = 10_000_000
-          while not partial_res_str.empty? do
-            chunk_size = size_limit
-            chunk_size = partial_res_str.length if chunk_size > partial_res_str.length
-            chunk = partial_res_str[0..chunk_size-1]
-            partial_res_str = partial_res_str[chunk_size..-1]
-            store_chunk page, chunk
-          end
-
-          Common::Loader.new(page, lib).load_top_level Axe::Configuration.instance.jslib
-          begin
-            axe_finish_run page
-          rescue
-            raise StandardError.new "axe.finishRun failed. Please check out https://github.com/dequelabs/axe-core-gems/blob/develop/error-handling.md"
-          end
-        }
+        user_page_load = (get_selenium page).manage.timeouts.page_load
+        (get_selenium page).manage.timeouts.page_load = 1
+        begin
+          @original_window = window_handle page
+          partial_results = run_partial_recursive(page, @context, lib, true)
+          throw partial_results if partial_results.respond_to?("key?") and partial_results.key?("errorMessage")
+          results = within_about_blank_context(page) { |page|
+            partial_res_str = partial_results.to_json
+            size_limit = 10_000_000
+            while not partial_res_str.empty? do
+              chunk_size = size_limit
+              chunk_size = partial_res_str.length if chunk_size > partial_res_str.length
+              chunk = partial_res_str[0..chunk_size-1]
+              partial_res_str = partial_res_str[chunk_size..-1]
+              store_chunk page, chunk
+            end
+
+            Common::Loader.new(page, lib).load_top_level Axe::Configuration.instance.jslib
+            begin
+              axe_finish_run page
+            rescue
+              raise StandardError.new "axe.finishRun failed. Please check out https://github.com/dequelabs/axe-core-gems/blob/develop/error-handling.md"
+            end
+
+          }
+        ensure
+          (get_selenium page).manage.timeouts.page_load = user_page_load
+        end
         Audit.new to_js, Results.new(results)
       end
 
@@ -108,15 +115,15 @@ def window_handle(page)
         page.current_window_handle
       end
 
-      def run_partial_recursive(page, context, lib, top_level = false)
+      def run_partial_recursive(page, context, lib, top_level = false, frame_stack = [])
         begin
+          current_window_handle = window_handle page
           if not top_level
             begin
               Common::Loader.new(page, lib).load_top_level Axe::Configuration.instance.jslib
             rescue
               return [nil]
             end
-
           end
 
           frame_contexts = get_frame_context_script page
@@ -134,12 +141,19 @@ def run_partial_recursive(page, context, lib, top_level = false)
           end
 
           for frame_context in frame_contexts
-            frame_selector = frame_context["frameSelector"]
-            frame_context = frame_context["frameContext"]
-            frame = axe_shadow_select page, frame_selector
-            switch_to_frame_by_handle page, frame
-            res = run_partial_recursive page, frame_context, lib
-            results += res
+            begin
+              frame_selector = frame_context["frameSelector"]
+              frame_context = frame_context["frameContext"]
+              frame = axe_shadow_select page, frame_selector
+              switch_to_frame_by_handle page, frame
+              res = run_partial_recursive page, frame_context, lib, false, [*frame_stack, frame]
+              results += res
+            rescue Selenium::WebDriver::Error::TimeoutError
+              page = get_selenium page
+              page.switch_to.window current_window_handle
+              frame_stack.each {|frame| page.switch_to.frame frame }
+              results.push nil
+            end
           end
 
         ensure

packages/axe-core-api/lib/axe/core.rb

@@ -3,6 +3,7 @@
 require_relative "../webdriver_script_adapter/query_selector_adapter"
 require_relative "../loader"
 require_relative "./configuration"
+require 'timeout'
 
 module Axe
   class Core
@@ -37,8 +38,22 @@ def use_run_partial
       Core.has_run_partial?(@page) and not Axe::Configuration.instance.legacy_mode
     end
 
+    def assert_frame_ready
+      begin
+        ready = Timeout.timeout(10) {
+          @page.evaluate_script <<-JS
+            document.readyState === 'complete'
+          JS
+        }
+      rescue Timeout::Error
+        ready = false
+      end
+      raise Exception.new "Page/frame not ready" if not ready
+    end
+
     def load_axe_core(source)
       return if already_loaded?
+      assert_frame_ready
       loader = Common::Loader.new(@page, self)
       loader.load_top_level source
       return if use_run_partial

packages/axe-core-api/spec/axe/core_spec.rb

@@ -7,6 +7,7 @@ module Axe
     let(:page) {
       spy("page", evaluate_script: false)
     }
+    before { allow(page).to receive(:evaluate_script).and_return(false, true, false) }
 
     describe "initialize" do
       # We have removed comments from `axe.min.js`, so excluding this test