[bugfix] Properly detect kwargs hashes vs optional positional args

lib/rspec/support/method_signature_verifier.rb

@@ -79,12 +79,31 @@ def invalid_kw_args_from(given_kw_args)
           given_kw_args - @allowed_kw_args
         end
 
-        # If the last argument is Hash, Ruby will treat only symbol keys as keyword arguments
-        # the rest will be grouped in another Hash and passed as positional argument.
+        # Considering the arg types, are there kw_args?
         def has_kw_args_in?(args)
-          Hash === args.last &&
-            could_contain_kw_args?(args) &&
-            (RubyFeatures.kw_arg_separation? || args.last.empty? || args.last.keys.any? { |x| x.is_a?(Symbol) })
+          if RubyFeatures.kw_arg_separation?
+            # If the last arg is a hash, depending on the signature it could be kw_args or a positional parameter.
+            return false unless Hash === args.last && could_contain_kw_args?(args)
+
+            # If the method signature contains **kwargs, the last argument being a hash means its the kwargs hash.
+            # The hash being a required positional argument is considered inside could_contain_kw_args
+            return true if @allows_any_kw_args
+
+            # If the position of the hash is beyond the count of required and optional positional
+            # args then it is the kwargs hash
+            return true if args.count > @max_non_kw_args
+
+            # Otherwise, the hash could be defined kw_args or an optional positional parameter
+            # inspect the keys against known kwargs to determine what it is
+            return args.last.keys.all? { |x| @allowed_kw_args.include?(x) }
+          else
+            # Version <= Ruby 2.7
+            # If the last argument is Hash, Ruby will treat only symbol keys as keyword arguments
+            # the rest will be grouped in another Hash and passed as positional argument.
+            Hash === args.last &&
+              could_contain_kw_args?(args) &&
+              (args.last.empty? || args.last.keys.any? { |x| x.is_a?(Symbol) })
+          end
         end
 
         # Without considering what the last arg is, could it