Add missing specs for END and Kernel#at_exit

core/kernel/at_exit_spec.rb

@@ -8,6 +8,10 @@
   it "is a private method" do
     Kernel.should have_private_instance_method(:at_exit)
   end
+
+  it "raises ArgumentError if called without a block" do
+    -> { at_exit }.should raise_error(ArgumentError, "called without a block")
+  end
 end
 
 describe "Kernel#at_exit" do

language/END_spec.rb

@@ -12,14 +12,22 @@
     ruby_exe("foo = 'foo'; END { puts foo }").should == "foo\n"
   end
 
+  it "warns when END is used in a method" do
+    ruby_exe(<<~ruby, args: "2>&1").should =~ /warning: END in method; use at_exit/
+      def foo
+        END { }
+      end
+    ruby
+  end
+
   context "END blocks and at_exit callbacks are mixed" do
     it "runs them all in reverse order of registration" do
-      ruby_exe(<<~RUBY).should == "at_exit#2\nEND#2\nat_exit#1\nEND#1\n"
+      ruby_exe(<<~ruby).should == "at_exit#2\nEND#2\nat_exit#1\nEND#1\n"
         END { puts 'END#1' }
         at_exit { puts 'at_exit#1' }
         END { puts 'END#2' }
         at_exit { puts 'at_exit#2' }
-      RUBY
+      ruby
     end
   end
 end

shared/kernel/at_exit.rb

@@ -13,10 +13,10 @@
     ruby_exe(code).should == "643"
   end
 
-  it "gives access to the last raised exception" do
+  it "gives access to the last raised exception - global variables $! and $@" do
     code = <<-EOC
       #{@method} {
-        puts "The exception matches: \#{$! == $exception} (message=\#{$!.message})"
+        puts "The exception matches: \#{$! == $exception && $@ == $exception.backtrace} (message=\#{$!.message})"
       }
 
       begin
@@ -56,4 +56,12 @@
     result.should.include?("handler ran\n")
     result.should.include?("syntax error")
   end
+
+  it "calls the nested handler right after the outer one if a handler is nested into another handler" do
+    ruby_exe(<<~ruby).should == "last\nbefore\nafter\nnested\nfirst\n"
+        #{@method} { puts :first }
+        #{@method} { puts :before; #{@method} { puts :nested }; puts :after };
+        #{@method} { puts :last }
+    ruby
+  end
 end