Add an ExceptionWrapper that wraps an exception and provide convenience helpers.

1 files changed, 77 insertions, 0 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
new file mode 100644
index 0000000000..96598b529d
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -0,0 +1,77 @@
+require 'active_support/core_ext/exception'
+
+module ActionDispatch
+  class ExceptionWrapper
+    cattr_accessor :rescue_responses
+    @@rescue_responses = Hash.new(:internal_server_error)
+    @@rescue_responses.merge!(
+      'ActionController::RoutingError'             => :not_found,
+      'AbstractController::ActionNotFound'         => :not_found,
+      'ActionController::MethodNotAllowed'         => :method_not_allowed,
+      'ActionController::NotImplemented'           => :not_implemented,
+      'ActionController::InvalidAuthenticityToken' => :unprocessable_entity
+    )
+
+    cattr_accessor :rescue_templates
+    @@rescue_templates = Hash.new('diagnostics')
+    @@rescue_templates.merge!(
+      'ActionView::MissingTemplate'         => 'missing_template',
+      'ActionController::RoutingError'      => 'routing_error',
+      'AbstractController::ActionNotFound'  => 'unknown_action',
+      'ActionView::Template::Error'         => 'template_error'
+    )
+
+    attr_reader :env, :exception
+
+    def initialize(env, exception)
+      @env = env
+      @exception = original_exception(exception)
+    end
+
+    def rescue_template
+      @@rescue_templates[@exception.class.name]
+    end
+
+    def status_code
+      Rack::Utils.status_code(@@rescue_responses[@exception.class.name])
+    end
+
+    def application_trace
+      clean_backtrace(:silent)
+    end
+
+    def framework_trace
+      clean_backtrace(:noise)
+    end
+
+    def full_trace
+      clean_backtrace(:all)
+    end
+
+    private
+
+    def original_exception(exception)
+      if registered_original_exception?(exception)
+        exception.original_exception
+      else
+        exception
+      end
+    end
+
+    def registered_original_exception?(exception)
+      exception.respond_to?(:original_exception) && @@rescue_responses.has_key?(exception.original_exception.class.name)
+    end
+
+    def clean_backtrace(*args)
+      if backtrace_cleaner
+        backtrace_cleaner.clean(@exception.backtrace, *args)
+      else
+        @exception.backtrace
+      end
+    end
+
+    def backtrace_cleaner
+      @backtrace_cleaner ||= @env['action_dispatch.backtrace_cleaner']
+    end
+  end
+end
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