Merge pull request #4266 from shuujii/add-no_method_error-tests-to-enumerator

Add `NoMethodError` tests to `mruby-enumerator`

mrbgems/mruby-enumerator/mrblib/enumerator.rb

@@ -118,13 +118,8 @@ class Enumerator
   def initialize(obj=NONE, meth=:each, *args, &block)
     if block
       obj = Generator.new(&block)
-    else
-      if obj == NONE
-        raise ArgumentError, "wrong number of arguments (given 0, expected 1+)"
-      end
-      if @obj && !self.respond_to?(meth)
-        raise NoMethodError, "undefined method #{meth}"
-      end
+    elsif obj == NONE
+      raise ArgumentError, "wrong number of arguments (given 0, expected 1+)"
     end
 
     @obj = obj

mrbgems/mruby-enumerator/test/enumerator.rb

@@ -6,11 +6,11 @@ class << @obj
   end
 end
 
-assert 'Enumerator' do
+assert 'Enumerator.class' do
   assert_equal Class, Enumerator.class
 end
 
-assert 'Enumerator' do
+assert 'Enumerator.superclass' do
   assert_equal Object, Enumerator.superclass
 end
 
@@ -418,7 +418,10 @@ assert 'nested iteration' do
 end
 
 assert 'Kernel#to_enum' do
+  e = nil
   assert_equal Enumerator, [].to_enum.class
+  assert_nothing_raised { e = [].to_enum(:_not_implemented_) }
+  assert_raise(NoMethodError) { e.first }
 end
 
 assert 'modifying existing methods' do