Dumping exceptions in live editor

[barriehadfield]

The live editor can crash the whole page if the user adds one of the lifecycle methods (before_mount, etc). The only fix so far is the patch below which catches and dumps an exception. Each change has comment #barrie

We need to find a better solution and this needs to be removed before the rename.

module React
find_and_render_component
  class NativeLibrary
    class << self
      def imports(native_name)
        @native_prefix = "#{native_name}."
        self
      end

      def rename(rename_list)
        # rename_list is a hash in the form: native_name => ruby_name, native_name => ruby_name
        rename_list.each do |js_name, ruby_name|
          native_name = lookup_native_name(js_name)
          if lookup_native_name(js_name)
            create_component_wrapper(self, native_name, ruby_name) ||
              create_library_wrapper(self, native_name, ruby_name)
          else
            raise "class #{name} < React::NativeLibrary could not import #{js_name}. "\
            "Native value #{scope_native_name(js_name)} is undefined."
          end
        end
      end

      def import_const_from_native(klass, const_name, create_library)
        begin
          native_name = lookup_native_name(const_name) ||
                        lookup_native_name(const_name[0].downcase + const_name[1..-1])
          native_name && (
            create_component_wrapper(klass, native_name, const_name) || (
              create_library &&
                create_library_wrapper(klass, native_name, const_name)))
        rescue Exception
          # barrie
        end
      end

      def const_missing(const_name)
        import_const_from_native(self, const_name, true) || super
      end

      def method_missing(method, *args, &block)
        component_class = const_get(method) if const_defined?(method, false)
        component_class ||= import_const_from_native(self, method, false)
        raise 'could not import a react component named: '\
              "#{scope_native_name method}" unless component_class
        React::RenderingContext.render(component_class, *args, &block)
      end

      private

      def lookup_native_name(js_name)
        native_name = scope_native_name(js_name)
        `eval(#{native_name}) !== undefined && native_name`
      # rubocop:disable Lint/RescueException  # that is what eval raises in Opal >= 0.10.
      rescue Exception
        nil
        # rubocop:enable Lint/RescueException
      end

      def scope_native_name(js_name)
        "#{@native_prefix}#{js_name}"
      end

      def create_component_wrapper(klass, native_name, ruby_name)
        if React::API.native_react_component?(native_name)
          new_klass = klass.const_set ruby_name, Class.new
          new_klass.class_eval do
            include Hyperloop::Component::Mixin
            imports native_name
          end
          new_klass
        end
      end

      def create_library_wrapper(klass, native_name, ruby_name)
        klass.const_set ruby_name, Class.new(React::NativeLibrary).imports(native_name)
      end
    end
  end
end

module Hyperloop
  class Component
    class << self
      def mounted_components
        @mounted_components ||= Set.new
      end

      def force_update!
        components = mounted_components.to_a
        components.each do |comp|
          next unless mounted_components.include? comp
          comp.force_update!
        end
      end
    end

    module Mixin
      def self.included(base)
        base.include(Hyperloop::Store::Mixin)
        base.include(React::Component::API)
        base.include(React::Callbacks)
        base.include(React::Component::Tags)
        base.include(React::Component::DslInstanceMethods)
        base.include(React::Component::ShouldComponentUpdate)
        base.class_eval do
          class_attribute :initial_state
          define_callback :before_mount
          define_callback :after_mount
          define_callback :before_receive_props
          define_callback :before_update
          define_callback :after_update
          define_callback :before_unmount
          define_callback(:after_error) { React::API.add_after_error_hook(base) }
        end
        base.extend(React::Component::ClassMethods)
      end

      def self.deprecation_warning(message)
        React::Component.deprecation_warning(name, message)
      end

      def deprecation_warning(message)
        React::Component.deprecation_warning(self.class.name, message)
      end

      def initialize(native_element)
        @native = native_element
        init_store
      end

      def emit(event_name, *args)
        if React::Event::BUILT_IN_EVENTS.include?(built_in_event_name = "on#{event_name.to_s.event_camelize}")
          params[built_in_event_name].call(*args)
        else
          params["on_#{event_name}"].call(*args)
        end
      end

      def component_will_mount
        begin
          React::IsomorphicHelpers.load_context(true) if React::IsomorphicHelpers.on_opal_client?
          React::State.set_state_context_to(self) do
            Hyperloop::Component.mounted_components << self
            run_callback(:before_mount)
          end
        rescue Exception
          # barrie
        end
      end

      def component_did_mount
        begin
          React::State.set_state_context_to(self) do
            run_callback(:after_mount)
            React::State.update_states_to_observe
          end
        rescue Exception
          # barrie
        end
      end

      def component_will_receive_props(next_props)
        # need to rethink how this works in opal-react, or if its actually that useful within the react.rb environment
        # for now we are just using it to clear processed_params
        begin
          React::State.set_state_context_to(self) { run_callback(:before_receive_props, next_props) }
          @_receiving_props = true
        rescue Exception
          # barrie
        end
      end

      def component_will_update(next_props, next_state)
        begin
          React::State.set_state_context_to(self) { run_callback(:before_update, next_props, next_state) }
          params._reset_all_others_cache if @_receiving_props
          @_receiving_props = false
        rescue Exception
          # barrie
        end
      end

      def component_did_update(prev_props, prev_state)
        begin
          React::State.set_state_context_to(self) do
            run_callback(:after_update, prev_props, prev_state)
            React::State.update_states_to_observe
          end
        rescue Exception
          # barrie
        end
      end

      def component_will_unmount
        begin
          React::State.set_state_context_to(self) do
            run_callback(:before_unmount)
            React::State.remove
            Hyperloop::Component.mounted_components.delete self
          end
        rescue Exception
          # barrie
        end
      end

      def component_did_catch(error, info)
        React::State.set_state_context_to(self) do
          run_callback(:after_error, error, info)
        end
      end

      attr_reader :waiting_on_resources

      def update_react_js_state(object, name, value)
        if object
          name = "#{object.class}.#{name}" unless object == self
          # Date.now() has only millisecond precision, if several notifications of
          # observer happen within a millisecond, updates may get lost.
          # to mitigate this the Math.random() appends some random number
          # this way notifactions will happen as expected by the rest of hyperloop
          set_state(
            '***_state_updated_at-***' => `Date.now() + Math.random()`,
            name => value
          )
        else
          set_state name => value
        end
      end

      def set_state_synchronously?
        @native.JS[:__opalInstanceSyncSetState]
      end

      def render
        raise 'no render defined'
      end unless method_defined?(:render)

      def _render_wrapper
        React::State.set_state_context_to(self, true) do
          element = React::RenderingContext.render(nil) { render || '' }
          @waiting_on_resources =
            element.waiting_on_resources if element.respond_to? :waiting_on_resources
          element
        end
      end

      def watch(value, &on_change)
        Observable.new(value, on_change)
      end

      def define_state(*args, &block)
        React::State.initialize_states(self, self.class.define_state(*args, &block))
      end
    end
  end
end