Use the Rails 6 Interceptor API and avoid a monkey patch

lib/web_console.rb

@@ -11,6 +11,7 @@ module WebConsole
   autoload :ExceptionMapper
   autoload :Session
   autoload :Injector
+  autoload :Interceptor
   autoload :Request
   autoload :WhinyRequest
   autoload :Permissions

lib/web_console/extensions.rb

@@ -21,27 +21,3 @@ def console(binding = Bindex.current_bindings.second)
     nil
   end
 end
-
-module ActionDispatch
-  class DebugExceptions
-    def render_exception_with_web_console(request, exception)
-      render_exception_without_web_console(request, exception).tap do
-        backtrace_cleaner = request.get_header("action_dispatch.backtrace_cleaner")
-        error = ExceptionWrapper.new(backtrace_cleaner, exception).exception
-
-        # Get the original exception if ExceptionWrapper decides to follow it.
-        Thread.current[:__web_console_exception] = error
-
-        # ActionView::Template::Error bypass ExceptionWrapper original
-        # exception following. The backtrace in the view is generated from
-        # reaching out to original_exception in the view.
-        if error.is_a?(ActionView::Template::Error)
-          Thread.current[:__web_console_exception] = error.cause
-        end
-      end
-    end
-
-    alias_method :render_exception_without_web_console, :render_exception
-    alias_method :render_exception, :render_exception_with_web_console
-  end
-end

lib/web_console/interceptor.rb

@@ -0,0 +1,18 @@
+module WebConsole
+  module Interceptor
+    def self.call(request, exception)
+      backtrace_cleaner = request.get_header("action_dispatch.backtrace_cleaner")
+      error = ActionDispatch::ExceptionWrapper.new(backtrace_cleaner, exception).exception
+
+      # Get the original exception if ExceptionWrapper decides to follow it.
+      Thread.current[:__web_console_exception] = error
+
+      # ActionView::Template::Error bypass ExceptionWrapper original
+      # exception following. The backtrace in the view is generated from
+      # reaching out to original_exception in the view.
+      if error.is_a?(ActionView::Template::Error)
+        Thread.current[:__web_console_exception] = error.cause
+      end
+    end
+  end
+end

lib/web_console/railtie.rb

@@ -10,6 +10,8 @@ class Railtie < ::Rails::Railtie
     initializer "web_console.initialize" do
       require "bindex"
       require "web_console/extensions"
+
+      ActionDispatch::DebugExceptions.register_interceptor(Interceptor)
     end
 
     initializer "web_console.development_only" do

test/web_console/interceptor_test.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+module WebConsole
+  class InterceptorTest < ActionDispatch::IntegrationTest
+    test "follows ActionView::Template::Error original error in Thread.current[:__web_console_exception]" do
+      request = Request.new({})
+      request.set_header("action_dispatch.backtrace_cleaner", ActiveSupport::BacktraceCleaner.new)
+
+      Interceptor.call(request, generate_template_error)
+
+      assert_equal 42, Thread.current[:__web_console_exception].bindings.first.eval("@ivar")
+    end
+
+    def generate_template_error
+      WebConsole::View.new(ActionView::LookupContext.new([])).render(inline: <<~ERB)
+        <% @ivar = 42 %>
+        <%= nil.raise %>
+        </h1
+      ERB
+    rescue ActionView::Template::Error => err
+      err
+    end
+  end
+end

web-console.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = ">= 2.4"
 
-  rails_version = ">= 5.2"
+  rails_version = ">= 6.0.0.a"
 
   s.add_dependency "railties",    rails_version
   s.add_dependency "activemodel", rails_version