bigger test for decode hook with types

mapstructure_test.go

diff --git a/mapstructure_test.go b/mapstructure_test.go
index 1444b13..0c9a31f 100644
--- a/mapstructure_test.go
+++ b/mapstructure_test.go
@@ -261,6 +261,43 @@
 	}
 }
 
+func TestDecode_DecodeHookType(t *testing.T) {
+	t.Parallel()
+
+	input := map[string]interface{}{
+		"vint": "WHAT",
+	}
+
+	decodeHook := func(from reflect.Type, to reflect.Type, v interface{}) (interface{}, error) {
+		if from.Kind() == reflect.String &&
+			to.Kind() != reflect.String {
+			return 5, nil
+		}
+
+		return v, nil
+	}
+
+	var result Basic
+	config := &DecoderConfig{
+		DecodeHook: decodeHook,
+		Result:     &result,
+	}
+
+	decoder, err := NewDecoder(config)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	err = decoder.Decode(input)
+	if err != nil {
+		t.Fatalf("got an err: %s", err)
+	}
+
+	if result.Vint != 5 {
+		t.Errorf("vint should be 5: %#v", result.Vint)
+	}
+}
+
 func TestDecode_Nil(t *testing.T) {
 	t.Parallel()