package json_test import ( "errors" "fmt" "testing" "time" "github.com/goccy/go-json" ) type recursiveT struct { A *recursiveT `json:"a,omitempty"` B *recursiveU `json:"b,omitempty"` C *recursiveU `json:"c,omitempty"` D string `json:"d,omitempty"` } type recursiveU struct { T *recursiveT `json:"t,omitempty"` } func Test_Marshal(t *testing.T) { t.Run("int", func(t *testing.T) { bytes, err := json.Marshal(-10) assertErr(t, err) assertEq(t, "int", `-10`, string(bytes)) }) t.Run("int8", func(t *testing.T) { bytes, err := json.Marshal(int8(-11)) assertErr(t, err) assertEq(t, "int8", `-11`, string(bytes)) }) t.Run("int16", func(t *testing.T) { bytes, err := json.Marshal(int16(-12)) assertErr(t, err) assertEq(t, "int16", `-12`, string(bytes)) }) t.Run("int32", func(t *testing.T) { bytes, err := json.Marshal(int32(-13)) assertErr(t, err) assertEq(t, "int32", `-13`, string(bytes)) }) t.Run("int64", func(t *testing.T) { bytes, err := json.Marshal(int64(-14)) assertErr(t, err) assertEq(t, "int64", `-14`, string(bytes)) }) t.Run("uint", func(t *testing.T) { bytes, err := json.Marshal(uint(10)) assertErr(t, err) assertEq(t, "uint", `10`, string(bytes)) }) t.Run("uint8", func(t *testing.T) { bytes, err := json.Marshal(uint8(11)) assertErr(t, err) assertEq(t, "uint8", `11`, string(bytes)) }) t.Run("uint16", func(t *testing.T) { bytes, err := json.Marshal(uint16(12)) assertErr(t, err) assertEq(t, "uint16", `12`, string(bytes)) }) t.Run("uint32", func(t *testing.T) { bytes, err := json.Marshal(uint32(13)) assertErr(t, err) assertEq(t, "uint32", `13`, string(bytes)) }) t.Run("uint64", func(t *testing.T) { bytes, err := json.Marshal(uint64(14)) assertErr(t, err) assertEq(t, "uint64", `14`, string(bytes)) }) t.Run("float32", func(t *testing.T) { bytes, err := json.Marshal(float32(3.14)) assertErr(t, err) assertEq(t, "float32", `3.14`, string(bytes)) }) t.Run("float64", func(t *testing.T) { bytes, err := json.Marshal(float64(3.14)) assertErr(t, err) assertEq(t, "float64", `3.14`, string(bytes)) }) t.Run("bool", func(t *testing.T) { bytes, err := json.Marshal(true) assertErr(t, err) assertEq(t, "bool", `true`, string(bytes)) }) t.Run("string", func(t *testing.T) { bytes, err := json.Marshal("hello world") assertErr(t, err) assertEq(t, "string", `"hello world"`, string(bytes)) }) t.Run("struct", func(t *testing.T) { bytes, err := json.Marshal(struct { A int `json:"a"` B uint `json:"b"` C string `json:"c"` D int `json:"-"` // ignore field a int `json:"aa"` // private field }{ A: -1, B: 1, C: "hello world", }) assertErr(t, err) assertEq(t, "struct", `{"a":-1,"b":1,"c":"hello world"}`, string(bytes)) t.Run("null", func(t *testing.T) { type T struct { A *struct{} `json:"a"` } var v T bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "struct", `{"a":null}`, string(bytes)) }) t.Run("recursive", func(t *testing.T) { bytes, err := json.Marshal(recursiveT{ A: &recursiveT{ B: &recursiveU{ T: &recursiveT{ D: "hello", }, }, C: &recursiveU{ T: &recursiveT{ D: "world", }, }, }, }) assertErr(t, err) assertEq(t, "recursive", `{"a":{"b":{"t":{"d":"hello"}},"c":{"t":{"d":"world"}}}}`, string(bytes)) }) t.Run("embedded", func(t *testing.T) { type T struct { A string `json:"a"` } type U struct { *T B string `json:"b"` } type T2 struct { A string `json:"a,omitempty"` } type U2 struct { *T2 B string `json:"b,omitempty"` } t.Run("exists field", func(t *testing.T) { bytes, err := json.Marshal(&U{ T: &T{ A: "aaa", }, B: "bbb", }) assertErr(t, err) assertEq(t, "embedded", `{"a":"aaa","b":"bbb"}`, string(bytes)) t.Run("omitempty", func(t *testing.T) { bytes, err := json.Marshal(&U2{ T2: &T2{ A: "aaa", }, B: "bbb", }) assertErr(t, err) assertEq(t, "embedded", `{"a":"aaa","b":"bbb"}`, string(bytes)) }) }) t.Run("none field", func(t *testing.T) { bytes, err := json.Marshal(&U{ B: "bbb", }) assertErr(t, err) assertEq(t, "embedded", `{"b":"bbb"}`, string(bytes)) t.Run("omitempty", func(t *testing.T) { bytes, err := json.Marshal(&U2{ B: "bbb", }) assertErr(t, err) assertEq(t, "embedded", `{"b":"bbb"}`, string(bytes)) }) }) }) t.Run("omitempty", func(t *testing.T) { type T struct { A int `json:",omitempty"` B int8 `json:",omitempty"` C int16 `json:",omitempty"` D int32 `json:",omitempty"` E int64 `json:",omitempty"` F uint `json:",omitempty"` G uint8 `json:",omitempty"` H uint16 `json:",omitempty"` I uint32 `json:",omitempty"` J uint64 `json:",omitempty"` K float32 `json:",omitempty"` L float64 `json:",omitempty"` O string `json:",omitempty"` P bool `json:",omitempty"` Q []int `json:",omitempty"` R map[string]interface{} `json:",omitempty"` S *struct{} `json:",omitempty"` T int `json:"t,omitempty"` } var v T v.T = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "struct", `{"t":1}`, string(bytes)) t.Run("int", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B int `json:"b"` } v.B = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "int", `{"b":1}`, string(bytes)) }) t.Run("int8", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B int8 `json:"b"` } v.B = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "int8", `{"b":1}`, string(bytes)) }) t.Run("int16", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B int16 `json:"b"` } v.B = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "int16", `{"b":1}`, string(bytes)) }) t.Run("int32", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B int32 `json:"b"` } v.B = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "int32", `{"b":1}`, string(bytes)) }) t.Run("int64", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B int64 `json:"b"` } v.B = 1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "int64", `{"b":1}`, string(bytes)) }) t.Run("string", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B string `json:"b"` } v.B = "b" bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "string", `{"b":"b"}`, string(bytes)) }) t.Run("float32", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B float32 `json:"b"` } v.B = 1.1 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "float32", `{"b":1.1}`, string(bytes)) }) t.Run("float64", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B float64 `json:"b"` } v.B = 3.14 bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "float64", `{"b":3.14}`, string(bytes)) }) t.Run("slice", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B []int `json:"b"` } v.B = []int{1, 2, 3} bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "slice", `{"b":[1,2,3]}`, string(bytes)) }) t.Run("array", func(t *testing.T) { var v struct { A int `json:"a,omitempty"` B [2]int `json:"b"` } v.B = [2]int{1, 2} bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "array", `{"b":[1,2]}`, string(bytes)) }) t.Run("map", func(t *testing.T) { v := new(struct { A int `json:"a,omitempty"` B map[string]interface{} `json:"b"` }) v.B = map[string]interface{}{"c": 1} bytes, err := json.Marshal(v) assertErr(t, err) assertEq(t, "array", `{"b":{"c":1}}`, string(bytes)) }) }) t.Run("head_omitempty", func(t *testing.T) { type T struct { A *struct{} `json:"a,omitempty"` } var v T bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "struct", `{}`, string(bytes)) }) t.Run("pointer_head_omitempty", func(t *testing.T) { type V struct{} type U struct { B *V `json:"b,omitempty"` } type T struct { A *U `json:"a"` } bytes, err := json.Marshal(&T{A: &U{}}) assertErr(t, err) assertEq(t, "struct", `{"a":{}}`, string(bytes)) }) t.Run("head_int_omitempty", func(t *testing.T) { type T struct { A int `json:"a,omitempty"` } var v T bytes, err := json.Marshal(&v) assertErr(t, err) assertEq(t, "struct", `{}`, string(bytes)) }) }) t.Run("slice", func(t *testing.T) { t.Run("[]int", func(t *testing.T) { bytes, err := json.Marshal([]int{1, 2, 3, 4}) assertErr(t, err) assertEq(t, "[]int", `[1,2,3,4]`, string(bytes)) }) t.Run("[]interface{}", func(t *testing.T) { bytes, err := json.Marshal([]interface{}{1, 2.1, "hello"}) assertErr(t, err) assertEq(t, "[]interface{}", `[1,2.1,"hello"]`, string(bytes)) }) }) t.Run("array", func(t *testing.T) { bytes, err := json.Marshal([4]int{1, 2, 3, 4}) assertErr(t, err) assertEq(t, "array", `[1,2,3,4]`, string(bytes)) }) t.Run("map", func(t *testing.T) { t.Run("map[string]int", func(t *testing.T) { bytes, err := json.Marshal(map[string]int{ "a": 1, "b": 2, "c": 3, "d": 4, }) assertErr(t, err) assertEq(t, "map", len(`{"a":1,"b":2,"c":3,"d":4}`), len(string(bytes))) }) t.Run("map[string]interface{}", func(t *testing.T) { type T struct { A int } v := map[string]interface{}{ "a": 1, "b": 2.1, "c": &T{ A: 10, }, "d": 4, } bytes, err := json.Marshal(v) assertErr(t, err) assertEq(t, "map[string]interface{}", len(`{"a":1,"b":2.1,"c":{"A":10},"d":4}`), len(string(bytes))) }) }) } type marshalJSON struct{} func (*marshalJSON) MarshalJSON() ([]byte, error) { return []byte(`1`), nil } func Test_MarshalJSON(t *testing.T) { t.Run("*struct", func(t *testing.T) { bytes, err := json.Marshal(&marshalJSON{}) assertErr(t, err) assertEq(t, "MarshalJSON", "1", string(bytes)) }) t.Run("time", func(t *testing.T) { bytes, err := json.Marshal(time.Time{}) assertErr(t, err) assertEq(t, "MarshalJSON", `"0001-01-01T00:00:00Z"`, string(bytes)) }) } func Test_MarshalIndent(t *testing.T) { prefix := "-" indent := "\t" t.Run("struct", func(t *testing.T) { bytes, err := json.MarshalIndent(struct { A int `json:"a"` B uint `json:"b"` C string `json:"c"` D int `json:"-"` // ignore field a int `json:"aa"` // private field }{ A: -1, B: 1, C: "hello world", }, prefix, indent) assertErr(t, err) result := "{\n-\t\"a\": -1,\n-\t\"b\": 1,\n-\t\"c\": \"hello world\"\n-}" assertEq(t, "struct", result, string(bytes)) }) t.Run("slice", func(t *testing.T) { t.Run("[]int", func(t *testing.T) { bytes, err := json.MarshalIndent([]int{1, 2, 3, 4}, prefix, indent) assertErr(t, err) result := "[\n-\t1,\n-\t2,\n-\t3,\n-\t4\n-]" assertEq(t, "[]int", result, string(bytes)) }) t.Run("[]interface{}", func(t *testing.T) { bytes, err := json.MarshalIndent([]interface{}{1, 2.1, "hello"}, prefix, indent) assertErr(t, err) result := "[\n-\t1,\n-\t2.1,\n-\t\"hello\"\n-]" assertEq(t, "[]interface{}", result, string(bytes)) }) }) t.Run("array", func(t *testing.T) { bytes, err := json.MarshalIndent([4]int{1, 2, 3, 4}, prefix, indent) assertErr(t, err) result := "[\n-\t1,\n-\t2,\n-\t3,\n-\t4\n-]" assertEq(t, "array", result, string(bytes)) }) t.Run("map", func(t *testing.T) { t.Run("map[string]int", func(t *testing.T) { bytes, err := json.MarshalIndent(map[string]int{ "a": 1, "b": 2, "c": 3, "d": 4, }, prefix, indent) assertErr(t, err) result := "{\n-\t\"a\": 1,\n-\t\"b\": 2,\n-\t\"c\": 3,\n-\t\"d\": 4\n-}" assertEq(t, "map", len(result), len(string(bytes))) }) t.Run("map[string]interface{}", func(t *testing.T) { type T struct { E int F int } v := map[string]interface{}{ "a": 1, "b": 2.1, "c": &T{ E: 10, F: 11, }, "d": 4, } bytes, err := json.MarshalIndent(v, prefix, indent) assertErr(t, err) result := "{\n-\t\"a\": 1,\n-\t\"b\": 2.1,\n-\t\"c\": {\n-\t\t\"E\": 10,\n-\t\t\"F\": 11\n-\t},\n-\t\"d\": 4\n-}" assertEq(t, "map[string]interface{}", len(result), len(string(bytes))) }) }) } type marshalerError struct{} func (*marshalerError) MarshalJSON() ([]byte, error) { return nil, errors.New("unexpected error") } func Test_MarshalerError(t *testing.T) { var v marshalerError _, err := json.Marshal(&v) expect := `json: error calling MarshalJSON for type *json_test.marshalerError: unexpected error` assertEq(t, "marshaler error", expect, fmt.Sprint(err)) }