1 files changed, 36 insertions, 3 deletions
diff --git a/spec/ruby/core/array/to_h_spec.rb b/spec/ruby/core/array/to_h_spec.rb
index e845d2c950..27a0b6112f 100644
--- a/spec/ruby/core/array/to_h_spec.rb
+++ b/spec/ruby/core/array/to_h_spec.rb
@@ -36,9 +36,42 @@ describe "Array#to_h" do
   end
 
   ruby_version_is "2.6" do
-    it "converts [key, value] pairs returned by the block to a hash" do
-      i = 0
-      [:a, :b].to_h {|k| [k, i += 1]}.should == { a: 1, b: 2 }
+    context "with block" do
+      it "converts [key, value] pairs returned by the block to a Hash" do
+        [:a, :b].to_h { |k| [k, k.to_s] }.should == { a: 'a', b: 'b' }
+      end
+
+      it "raises ArgumentError if block returns longer or shorter array" do
+        -> do
+          [:a, :b].to_h { |k| [k, k.to_s, 1] }
+        end.should raise_error(ArgumentError, /wrong array length at 0/)
+
+        -> do
+          [:a, :b].to_h { |k| [k] }
+        end.should raise_error(ArgumentError, /wrong array length at 0/)
+      end
+
+      it "raises TypeError if block returns something other than Array" do
+        -> do
+          [:a, :b].to_h { |k| "not-array" }
+        end.should raise_error(TypeError, /wrong element type String at 0/)
+      end
+
+      it "coerces returned pair to Array with #to_ary" do
+        x = mock('x')
+        x.stub!(:to_ary).and_return([:b, 'b'])
+
+        [:a].to_h { |k| x }.should == { :b => 'b' }
+      end
+
+      it "does not coerce returned pair to Array with #to_a" do
+        x = mock('x')
+        x.stub!(:to_a).and_return([:b, 'b'])
+
+        -> do
+          [:a].to_h { |k| x }
+        end.should raise_error(TypeError, /wrong element type MockObject at 0/)
+      end
     end
   end
 end