// the value pointed at by the pointer. If the pointer is nil, Unmarshal
// allocates a new value for it to point to.
//
+// To unmarshal JSON into a value implementing the Unmarshaler interface,
+// Unmarshal calls that value's UnmarshalJSON method, including
+// when the input is a JSON null.
+// Otherwise, if the value implements encoding.TextUnmarshaler
+// and the input is a JSON quoted string, Unmarshal calls that value's
+// UnmarshalText method with the unquoted form of the string.
+//
// To unmarshal JSON into a struct, Unmarshal matches incoming object
// keys to the keys used by Marshal (either the struct field name or its tag),
// preferring an exact match but also accepting a case-insensitive match.
// The input can be assumed to be a valid encoding of
// a JSON value. UnmarshalJSON must copy the JSON data
// if it wishes to retain the data after returning.
+//
+// By convention, to approximate the behavior of Unmarshal itself,
+// Unmarshalers implement UnmarshalJSON([]byte("null")) as a no-op.
type Unmarshaler interface {
UnmarshalJSON([]byte) error
}
if u, ok := v.Interface().(Unmarshaler); ok {
return u, nil, reflect.Value{}
}
- if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
- return nil, u, reflect.Value{}
+ if !decodingNull {
+ if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
+ return nil, u, reflect.Value{}
+ }
}
}
v = v.Elem()
d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
return
}
- wantptr := item[0] == 'n' // null
- u, ut, pv := d.indirect(v, wantptr)
+ isNull := item[0] == 'n' // null
+ u, ut, pv := d.indirect(v, isNull)
if u != nil {
err := u.UnmarshalJSON(item)
if err != nil {
if fromQuoted {
d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
} else {
- d.saveError(&UnmarshalTypeError{Value: "string", Type: v.Type(), Offset: int64(d.off)})
+ var val string
+ switch item[0] {
+ case 'n':
+ val = "null"
+ case 't', 'f':
+ val = "bool"
+ default:
+ val = "number"
+ }
+ d.saveError(&UnmarshalTypeError{Value: val, Type: v.Type(), Offset: int64(d.off)})
}
return
}
"fmt"
"image"
"math"
+ "math/big"
"net"
"reflect"
"strconv"
}
}
+type NullTest struct {
+ Bool bool
+ Int int
+ Int8 int8
+ Int16 int16
+ Int32 int32
+ Int64 int64
+ Uint uint
+ Uint8 uint8
+ Uint16 uint16
+ Uint32 uint32
+ Uint64 uint64
+ Float32 float32
+ Float64 float64
+ String string
+ PBool *bool
+ Map map[string]string
+ Slice []string
+ Interface interface{}
+
+ PRaw *RawMessage
+ PTime *time.Time
+ PBigInt *big.Int
+ PText *MustNotUnmarshalText
+ PBuffer *bytes.Buffer // has methods, just not relevant ones
+ PStruct *struct{}
+
+ Raw RawMessage
+ Time time.Time
+ BigInt big.Int
+ Text MustNotUnmarshalText
+ Buffer bytes.Buffer
+ Struct struct{}
+}
+
+type NullTestStrings struct {
+ Bool bool `json:",string"`
+ Int int `json:",string"`
+ Int8 int8 `json:",string"`
+ Int16 int16 `json:",string"`
+ Int32 int32 `json:",string"`
+ Int64 int64 `json:",string"`
+ Uint uint `json:",string"`
+ Uint8 uint8 `json:",string"`
+ Uint16 uint16 `json:",string"`
+ Uint32 uint32 `json:",string"`
+ Uint64 uint64 `json:",string"`
+ Float32 float32 `json:",string"`
+ Float64 float64 `json:",string"`
+ String string `json:",string"`
+ PBool *bool `json:",string"`
+ Map map[string]string `json:",string"`
+ Slice []string `json:",string"`
+ Interface interface{} `json:",string"`
+
+ PRaw *RawMessage `json:",string"`
+ PTime *time.Time `json:",string"`
+ PBigInt *big.Int `json:",string"`
+ PText *MustNotUnmarshalText `json:",string"`
+ PBuffer *bytes.Buffer `json:",string"`
+ PStruct *struct{} `json:",string"`
+
+ Raw RawMessage `json:",string"`
+ Time time.Time `json:",string"`
+ BigInt big.Int `json:",string"`
+ Text MustNotUnmarshalText `json:",string"`
+ Buffer bytes.Buffer `json:",string"`
+ Struct struct{} `json:",string"`
+}
+
// JSON null values should be ignored for primitives and string values instead of resulting in an error.
// Issue 2540
func TestUnmarshalNulls(t *testing.T) {
+ // Unmarshal docs:
+ // The JSON null value unmarshals into an interface, map, pointer, or slice
+ // by setting that Go value to nil. Because null is often used in JSON to mean
+ // ``not present,'' unmarshaling a JSON null into any other Go type has no effect
+ // on the value and produces no error.
+
jsonData := []byte(`{
- "Bool" : null,
- "Int" : null,
- "Int8" : null,
- "Int16" : null,
- "Int32" : null,
- "Int64" : null,
- "Uint" : null,
- "Uint8" : null,
- "Uint16" : null,
- "Uint32" : null,
- "Uint64" : null,
- "Float32" : null,
- "Float64" : null,
- "String" : null}`)
-
- nulls := All{
- Bool: true,
- Int: 2,
- Int8: 3,
- Int16: 4,
- Int32: 5,
- Int64: 6,
- Uint: 7,
- Uint8: 8,
- Uint16: 9,
- Uint32: 10,
- Uint64: 11,
- Float32: 12.1,
- Float64: 13.1,
- String: "14"}
+ "Bool" : null,
+ "Int" : null,
+ "Int8" : null,
+ "Int16" : null,
+ "Int32" : null,
+ "Int64" : null,
+ "Uint" : null,
+ "Uint8" : null,
+ "Uint16" : null,
+ "Uint32" : null,
+ "Uint64" : null,
+ "Float32" : null,
+ "Float64" : null,
+ "String" : null,
+ "PBool": null,
+ "Map": null,
+ "Slice": null,
+ "Interface": null,
+ "PRaw": null,
+ "PTime": null,
+ "PBigInt": null,
+ "PText": null,
+ "PBuffer": null,
+ "PStruct": null,
+ "Raw": null,
+ "Time": null,
+ "BigInt": null,
+ "Text": null,
+ "Buffer": null,
+ "Struct": null
+ }`)
+ nulls := NullTest{
+ Bool: true,
+ Int: 2,
+ Int8: 3,
+ Int16: 4,
+ Int32: 5,
+ Int64: 6,
+ Uint: 7,
+ Uint8: 8,
+ Uint16: 9,
+ Uint32: 10,
+ Uint64: 11,
+ Float32: 12.1,
+ Float64: 13.1,
+ String: "14",
+ PBool: new(bool),
+ Map: map[string]string{},
+ Slice: []string{},
+ Interface: new(MustNotUnmarshalJSON),
+ PRaw: new(RawMessage),
+ PTime: new(time.Time),
+ PBigInt: new(big.Int),
+ PText: new(MustNotUnmarshalText),
+ PStruct: new(struct{}),
+ PBuffer: new(bytes.Buffer),
+ Raw: RawMessage("123"),
+ Time: time.Unix(123456789, 0),
+ BigInt: *big.NewInt(123),
+ }
+
+ before := nulls.Time.String()
err := Unmarshal(jsonData, &nulls)
if err != nil {
if !nulls.Bool || nulls.Int != 2 || nulls.Int8 != 3 || nulls.Int16 != 4 || nulls.Int32 != 5 || nulls.Int64 != 6 ||
nulls.Uint != 7 || nulls.Uint8 != 8 || nulls.Uint16 != 9 || nulls.Uint32 != 10 || nulls.Uint64 != 11 ||
nulls.Float32 != 12.1 || nulls.Float64 != 13.1 || nulls.String != "14" {
-
t.Errorf("Unmarshal of null values affected primitives")
}
+
+ if nulls.PBool != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PBool")
+ }
+ if nulls.Map != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.Map")
+ }
+ if nulls.Slice != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.Slice")
+ }
+ if nulls.Interface != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.Interface")
+ }
+ if nulls.PRaw != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PRaw")
+ }
+ if nulls.PTime != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PTime")
+ }
+ if nulls.PBigInt != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PBigInt")
+ }
+ if nulls.PText != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PText")
+ }
+ if nulls.PBuffer != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PBuffer")
+ }
+ if nulls.PStruct != nil {
+ t.Errorf("Unmarshal of null did not clear nulls.PStruct")
+ }
+
+ if string(nulls.Raw) != "null" {
+ t.Errorf("Unmarshal of RawMessage null did not record null: %v", string(nulls.Raw))
+ }
+ if nulls.Time.String() != before {
+ t.Errorf("Unmarshal of time.Time null set time to %v", nulls.Time.String())
+ }
+ if nulls.BigInt.String() != "123" {
+ t.Errorf("Unmarshal of big.Int null set int to %v", nulls.BigInt.String())
+ }
+}
+
+type MustNotUnmarshalJSON struct{}
+
+func (x MustNotUnmarshalJSON) UnmarshalJSON(data []byte) error {
+ return errors.New("MustNotUnmarshalJSON was used")
+}
+
+type MustNotUnmarshalText struct{}
+
+func (x MustNotUnmarshalText) UnmarshalText(text []byte) error {
+ return errors.New("MustNotUnmarshalText was used")
}
func TestStringKind(t *testing.T) {
{nil, "json: Unmarshal(nil)"},
{struct{}{}, "json: Unmarshal(non-pointer struct {})"},
{(*int)(nil), "json: Unmarshal(nil *int)"},
- {new(net.IP), "json: cannot unmarshal string into Go value of type *net.IP"},
+ {new(net.IP), "json: cannot unmarshal number into Go value of type *net.IP"},
}
func TestInvalidUnmarshalText(t *testing.T) {