Decouple from sprockets-rails

lib/importmap/engine.rb

@@ -7,6 +7,7 @@ module Importmap
   class Engine < ::Rails::Engine
     config.importmap = ActiveSupport::OrderedOptions.new
     config.importmap.sweep_cache = Rails.env.development? || Rails.env.test?
+    config.importmap.rescuable_asset_errors = []
 
     config.autoload_once_paths = %W( #{root}/app/helpers )
 
@@ -49,5 +50,11 @@ class Engine < ::Rails::Engine
         helper Importmap::ImportmapTagsHelper
       end
     end
+
+    initializer 'importmap.rescuable_asset_errors' do |app|
+      if defined?(Sprockets::Rails)
+        app.config.importmap.rescuable_asset_errors << Sprockets::Rails::Helper::AssetNotFound
+      end
+    end
   end
 end

lib/importmap/map.rb

@@ -87,13 +87,21 @@ def clear_cache
       @cached_preloaded_module_paths = nil
     end
 
+    def rescuable_asset_error?(error)
+      Rails.application.config.importmap.rescuable_asset_errors.any? { |e| error.is_a?(e) }
+    end
+
     def resolve_asset_paths(paths, resolver:)
       paths.transform_values do |mapping|
         begin
           resolver.asset_path(mapping.path)
-        rescue Sprockets::Rails::Helper::AssetNotFound
-          Rails.logger.warn "Importmap skipped missing path: #{mapping.path}"
-          nil
+        rescue => e
+          if rescuable_asset_error?(e)
+            Rails.logger.warn "Importmap skipped missing path: #{mapping.path}"
+            nil
+          else
+            raise e
+          end
         end
       end.compact
     end