separate TypeError cases on dig

Author: nobu

core/hash/dig_spec.rb

@@ -29,14 +29,19 @@ def obj.dig(*args); [ 42 ] end
 
       h.dig(:foo, 0, :bar).should == [ 1 ]
       h.dig(:foo, 0, :bar, 0).should == 1
-      lambda { h.dig(:foo, 0, :bar, 0, 0) }.should raise_error(TypeError)
       h.dig(:foo, 1, 1).should == 'str'
-      lambda { h.dig(:foo, 1, 1, 0) }.should raise_error(TypeError)
       # MRI does not recurse values returned from `obj.dig`
       h.dig(:foo, 1, 0, 0).should == [ 42 ]
       h.dig(:foo, 1, 0, 0, 10).should == [ 42 ]
     end
 
+    it "raises TypeError if an intermediate element does not respond to #dig" do
+      h = {}
+      h[:foo] = [ { :bar => [ 1 ] }, [ nil, 'str' ] ]
+      lambda { h.dig(:foo, 0, :bar, 0, 0) }.should raise_error(TypeError)
+      lambda { h.dig(:foo, 1, 1, 0) }.should raise_error(TypeError)
+    end
+
     it "calls #dig on the result of #[] with the remaining arguments" do
       h = { foo: { bar: { baz: 42 } } }
       h[:foo].should_receive(:dig).with(:bar, :baz).and_return(42)