lib/dry/errors/not_implemented.rb in dry-behaviour-0.6.0 vs lib/dry/errors/not_implemented.rb in dry-behaviour-0.7.0

@@ -1,16 +1,40 @@
 module Dry
   module Protocol
     class NotImplemented < StandardError
-      def initialize(type, proto, impl)
-        super case type
-              when :protocol
-                "Protocol “#{proto}” is not implemented for “#{impl}”."
-              when :method
-                "Protocol “#{proto}” does not declare method “#{impl}”."
-              else
-                "Protocol “#{proto}” is invalid."
-              end
+      attr_reader :proto, :details
+
+      def initialize(type, proto, **details)
+        @proto, @details = proto, details
+
+        @details[:message] =
+          case type
+          when :protocol
+            "Protocol “#{@proto}” is not implemented for “#{@details[:receiver].class}”."
+          when :method
+            "Protocol “#{@proto}” does not declare method “#{@details[:method]}”."
+          when :nested
+            "Protocol “#{@proto}” failed to invoke the implementation.\n" \
+            " ⮩  caused by “#{cause.class}” with a message\n" \
+            " ⮩    “#{cause.message}”\n" \
+            " ⮩  rescue this exception and inspect `NotImplemented#cause' for details."
+          else
+            "Protocol “#{proto}” is invalid."
+          end
+
+        super(@details[:message])
+
+        if @details[:cause]
+          set_backtrace(
+            @details[:cause].backtrace.reject do |line| # FIXME drop_while ??
+              line =~ %r[dry-behaviour/lib/dry/behaviour]
+            end
+          )
+        end
+      end
+
+      def cause
+        @details[:cause] ||= super
       end
     end
   end
 end