consolidate more tests

value_tests/map_test.go

@@ -3,6 +3,7 @@ package test
 import "math/big"
 
 func init() {
+	nilMap := map[string]string(nil)
 	marshalCases = append(marshalCases,
 		map[string]interface{}{"abc": 1},
 		map[string]MyInterface{"hello": MyString("world")},
@@ -17,10 +18,15 @@ func init() {
 			uint64(2): "a",
 			uint64(4): "a",
 		},
+		nilMap,
+		&nilMap,
 	)
 	unmarshalCases = append(unmarshalCases, unmarshalCase{
 		ptr: (*map[string]string)(nil),
 		input: `{"k\"ey": "val"}`,
+	}, unmarshalCase{
+		ptr: (*map[string]string)(nil),
+		input: `null`,
 	})
 }
 

value_tests/slice_test.go

@@ -1,5 +1,14 @@
 package test
 
 func init() {
-	marshalCases = append(marshalCases, []interface{}{"hello"})
-}
+	nilSlice := []string(nil)
+	marshalCases = append(marshalCases,
+		[]interface{}{"hello"},
+		nilSlice,
+		&nilSlice,
+	)
+	unmarshalCases = append(unmarshalCases, unmarshalCase{
+		ptr:   (*[]string)(nil),
+		input: "null",
+	})
+}

value_tests/struct_test.go

@@ -11,6 +11,11 @@ func init() {
 			Field interface{}
 		})(nil),
 		input: `{"Field": "hello"}`,
+	}, unmarshalCase{
+		ptr: (*struct {
+			Field int `json:"field"`
+		})(nil),
+		input: `{"field": null}`,
 	})
 	marshalCases = append(marshalCases,
 		struct {

value_tests/value_test.go

@@ -15,7 +15,9 @@ type unmarshalCase struct {
 
 var unmarshalCases []unmarshalCase
 
-var marshalCases []interface{}
+var marshalCases = []interface{}{
+	nil,
+}
 
 func Test_unmarshal(t *testing.T) {
 	should := require.New(t)