Merge pull request #513 from AllenX2018/fix-issue-510

fix issue 510

README.md

@@ -1,5 +1,5 @@
 [![Sourcegraph](https://sourcegraph.com/github.com/json-iterator/go/-/badge.svg)](https://sourcegraph.com/github.com/json-iterator/go?badge)
-[![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/json-iterator/go)
+[![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](https://pkg.go.dev/github.com/json-iterator/go)
 [![Build Status](https://travis-ci.org/json-iterator/go.svg?branch=master)](https://travis-ci.org/json-iterator/go)
 [![codecov](https://codecov.io/gh/json-iterator/go/branch/master/graph/badge.svg)](https://codecov.io/gh/json-iterator/go)
 [![rcard](https://goreportcard.com/badge/github.com/json-iterator/go)](https://goreportcard.com/report/github.com/json-iterator/go)
@@ -18,16 +18,16 @@ Source code: https://github.com/json-iterator/go-benchmark/blob/master/src/githu
 
 Raw Result (easyjson requires static code generation)
 
-| | ns/op | allocation bytes | allocation times |
-| --- | --- | --- | --- |
-| std decode | 35510 ns/op | 1960 B/op | 99 allocs/op |
-| easyjson decode | 8499 ns/op | 160 B/op | 4 allocs/op |
-| jsoniter decode | 5623 ns/op | 160 B/op | 3 allocs/op |
-| std encode | 2213 ns/op | 712 B/op | 5 allocs/op |
-| easyjson encode | 883 ns/op | 576 B/op | 3 allocs/op |
-| jsoniter encode | 837 ns/op | 384 B/op | 4 allocs/op |
+|                 | ns/op       | allocation bytes | allocation times |
+| --------------- | ----------- | ---------------- | ---------------- |
+| std decode      | 35510 ns/op | 1960 B/op        | 99 allocs/op     |
+| easyjson decode | 8499 ns/op  | 160 B/op         | 4 allocs/op      |
+| jsoniter decode | 5623 ns/op  | 160 B/op         | 3 allocs/op      |
+| std encode      | 2213 ns/op  | 712 B/op         | 5 allocs/op      |
+| easyjson encode | 883 ns/op   | 576 B/op         | 3 allocs/op      |
+| jsoniter encode | 837 ns/op   | 384 B/op         | 4 allocs/op      |
 
-Always benchmark with your own workload. 
+Always benchmark with your own workload.
 The result depends heavily on the data input.
 
 # Usage
@@ -41,10 +41,10 @@ import "encoding/json"
 json.Marshal(&data)
 ```
 
-with 
+with
 
 ```go
-import "github.com/json-iterator/go"
+import jsoniter "github.com/json-iterator/go"
 
 var json = jsoniter.ConfigCompatibleWithStandardLibrary
 json.Marshal(&data)
@@ -60,7 +60,7 @@ json.Unmarshal(input, &data)
 with
 
 ```go
-import "github.com/json-iterator/go"
+import jsoniter "github.com/json-iterator/go"
 
 var json = jsoniter.ConfigCompatibleWithStandardLibrary
 json.Unmarshal(input, &data)
@@ -78,10 +78,10 @@ go get github.com/json-iterator/go
 
 Contributors
 
-* [thockin](https://github.com/thockin) 
-* [mattn](https://github.com/mattn)
-* [cch123](https://github.com/cch123)
-* [Oleg Shaldybin](https://github.com/olegshaldybin)
-* [Jason Toffaletti](https://github.com/toffaletti)
+- [thockin](https://github.com/thockin)
+- [mattn](https://github.com/mattn)
+- [cch123](https://github.com/cch123)
+- [Oleg Shaldybin](https://github.com/olegshaldybin)
+- [Jason Toffaletti](https://github.com/toffaletti)
 
 Report issue or pull request, or email taowen@gmail.com, or [![Gitter chat](https://badges.gitter.im/gitterHQ/gitter.png)](https://gitter.im/json-iterator/Lobby)

any_str.go

@@ -64,7 +64,6 @@ func (any *stringAny) ToInt64() int64 {
 
 	flag := 1
 	startPos := 0
-	endPos := 0
 	if any.val[0] == '+' || any.val[0] == '-' {
 		startPos = 1
 	}
@@ -73,6 +72,7 @@ func (any *stringAny) ToInt64() int64 {
 		flag = -1
 	}
 
+	endPos := startPos
 	for i := startPos; i < len(any.val); i++ {
 		if any.val[i] >= '0' && any.val[i] <= '9' {
 			endPos = i + 1
@@ -98,7 +98,6 @@ func (any *stringAny) ToUint64() uint64 {
 	}
 
 	startPos := 0
-	endPos := 0
 
 	if any.val[0] == '-' {
 		return 0
@@ -107,6 +106,7 @@ func (any *stringAny) ToUint64() uint64 {
 		startPos = 1
 	}
 
+	endPos := startPos
 	for i := startPos; i < len(any.val); i++ {
 		if any.val[i] >= '0' && any.val[i] <= '9' {
 			endPos = i + 1

benchmarks/stream_test.go

@@ -0,0 +1,128 @@
+package test
+
+import (
+	"bytes"
+	"strconv"
+	"testing"
+
+	jsoniter "github.com/json-iterator/go"
+)
+
+func Benchmark_stream_encode_big_object(b *testing.B) {
+	var buf bytes.Buffer
+	var stream = jsoniter.NewStream(jsoniter.ConfigDefault, &buf, 100)
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		stream.Reset(&buf)
+		encodeObject(stream)
+		if stream.Error != nil {
+			b.Errorf("error: %+v", stream.Error)
+		}
+	}
+}
+
+func TestEncodeObject(t *testing.T) {
+	var stream = jsoniter.NewStream(jsoniter.ConfigDefault, nil, 100)
+	encodeObject(stream)
+	if stream.Error != nil {
+		t.Errorf("error encoding a test object: %+v", stream.Error)
+		return
+	}
+	var m = make(map[string]interface{})
+	if err := jsoniter.Unmarshal(stream.Buffer(), &m); err != nil {
+		t.Errorf("error unmarshaling a test object: %+v", err)
+		return
+	}
+}
+
+func encodeObject(stream *jsoniter.Stream) {
+	stream.WriteObjectStart()
+
+	stream.WriteObjectField("objectId")
+	stream.WriteUint64(8838243212)
+
+	stream.WriteMore()
+	stream.WriteObjectField("name")
+	stream.WriteString("Jane Doe")
+
+	stream.WriteMore()
+	stream.WriteObjectField("address")
+	stream.WriteObjectStart()
+	for i, field := range addressFields {
+		if i != 0 {
+			stream.WriteMore()
+		}
+		stream.WriteObjectField(field.key)
+		stream.WriteString(field.val)
+	}
+
+	stream.WriteMore()
+	stream.WriteObjectField("geo")
+	{
+		stream.WriteObjectStart()
+		stream.WriteObjectField("latitude")
+		stream.WriteFloat64(-154.550817)
+		stream.WriteMore()
+		stream.WriteObjectField("longitude")
+		stream.WriteFloat64(-84.176159)
+		stream.WriteObjectEnd()
+
+	}
+	stream.WriteObjectEnd()
+
+	stream.WriteMore()
+	stream.WriteObjectField("specialties")
+	stream.WriteArrayStart()
+	for i, s := range specialties {
+		if i != 0 {
+			stream.WriteMore()
+		}
+		stream.WriteString(s)
+	}
+	stream.WriteArrayEnd()
+
+	stream.WriteMore()
+	for i, text := range longText {
+		if i != 0 {
+			stream.WriteMore()
+		}
+		stream.WriteObjectField("longText" + strconv.Itoa(i))
+		stream.WriteString(text)
+	}
+
+	for i := 0; i < 25; i++ {
+		num := i * 18328
+		stream.WriteMore()
+		stream.WriteObjectField("integerField" + strconv.Itoa(i))
+		stream.WriteInt64(int64(num))
+	}
+
+	stream.WriteObjectEnd()
+}
+
+type field struct{ key, val string }
+
+var (
+	addressFields = []field{
+		{"address1", "123 Example St"},
+		{"address2", "Apartment 5D, Suite 3"},
+		{"city", "Miami"},
+		{"state", "FL"},
+		{"postalCode", "33133"},
+		{"country", "US"},
+	}
+	specialties = []string{
+		"Web Design",
+		"Go Programming",
+		"Tennis",
+		"Cycling",
+		"Mixed martial arts",
+	}
+	longText = []string{
+		`Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.`,
+		`Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?`,
+		`But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful. Nor again is there anyone who loves or pursues or desires to obtain pain of itself, because it is pain, but because occasionally circumstances occur in which toil and pain can procure him some great pleasure. To take a trivial example, which of us ever undertakes laborious physical exercise, except to obtain some advantage from it? But who has any right to find fault with a man who chooses to enjoy a pleasure that has no annoying consequences, or one who avoids a pain that produces no resultant pleasure?`,
+		`At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet ut et voluptates repudiandae sint et molestiae non recusandae. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.`,
+		`On the other hand, we denounce with righteous indignation and dislike men who are so beguiled and demoralized by the charms of pleasure of the moment, so blinded by desire, that they cannot foresee the pain and trouble that are bound to ensue; and equal blame belongs to those who fail in their duty through weakness of will, which is the same as saying through shrinking from toil and pain. These cases are perfectly simple and easy to distinguish. In a free hour, when our power of choice is untrammelled and when nothing prevents our being able to do what we like best, every pleasure is to be welcomed and every pain avoided. But in certain circumstances and owing to the claims of duty or the obligations of business it will frequently occur that pleasures have to be repudiated and annoyances accepted. The wise man therefore always holds in these matters to this principle of selection: he rejects pleasures to secure other greater pleasures, or else he endures pains to avoid worse pains.`,
+	}
+)

config.go

@@ -183,11 +183,11 @@ func (cfg *frozenConfig) validateJsonRawMessage(extension EncoderExtension) {
 	encoder := &funcEncoder{func(ptr unsafe.Pointer, stream *Stream) {
 		rawMessage := *(*json.RawMessage)(ptr)
 		iter := cfg.BorrowIterator([]byte(rawMessage))
+		defer cfg.ReturnIterator(iter)
 		iter.Read()
-		if iter.Error != nil {
+		if iter.Error != nil && iter.Error != io.EOF {
 			stream.WriteRaw("null")
 		} else {
-			cfg.ReturnIterator(iter)
 			stream.WriteRaw(string(rawMessage))
 		}
 	}, func(ptr unsafe.Pointer) bool {

extra/naming_strategy.go

@@ -18,6 +18,9 @@ type namingStrategyExtension struct {
 
 func (extension *namingStrategyExtension) UpdateStructDescriptor(structDescriptor *jsoniter.StructDescriptor) {
 	for _, binding := range structDescriptor.Fields {
+		if unicode.IsLower(rune(binding.Field.Name()[0])) || binding.Field.Name()[0] == '_'{
+			continue
+		}
 		tag, hastag := binding.Field.Tag().Lookup("json")
 		if hastag {
 			tagParts := strings.Split(tag, ",")

extra/naming_strategy_test.go

@@ -48,3 +48,19 @@ func Test_set_naming_strategy_with_omitempty(t *testing.T) {
 	should.Nil(err)
 	should.Equal(`{"user_name":"taowen"}`, string(output))
 }
+
+func Test_set_naming_strategy_with_private_field(t *testing.T) {
+	should := require.New(t)
+	SetNamingStrategy(LowerCaseWithUnderscores)
+	output, err := jsoniter.Marshal(struct {
+		UserName string
+		userId   int
+		_UserAge int
+	}{
+		UserName: "allen",
+		userId:   100,
+		_UserAge: 30,
+	})
+	should.Nil(err)
+	should.Equal(`{"user_name":"allen"}`, string(output))
+}

go.sum

@@ -9,6 +9,7 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 h1:Esafd1046DLD
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=

iter_float.go

@@ -288,6 +288,9 @@ non_decimal_loop:
 				return iter.readFloat64SlowPath()
 			}
 			value = (value << 3) + (value << 1) + uint64(ind)
+			if value > maxFloat64 {
+				return iter.readFloat64SlowPath()
+			}
 		}
 	}
 	return iter.readFloat64SlowPath()

iter_int.go

@@ -9,6 +9,7 @@ var intDigits []int8
 
 const uint32SafeToMultiply10 = uint32(0xffffffff)/10 - 1
 const uint64SafeToMultiple10 = uint64(0xffffffffffffffff)/10 - 1
+const maxFloat64 = 1<<53 - 1
 
 func init() {
 	intDigits = make([]int8, 256)
@@ -339,7 +340,7 @@ func (iter *Iterator) readUint64(c byte) (ret uint64) {
 }
 
 func (iter *Iterator) assertInteger() {
-	if iter.head < len(iter.buf) && iter.buf[iter.head] == '.' {
+	if iter.head < iter.tail && iter.buf[iter.head] == '.' {
 		iter.ReportError("assertInteger", "can not decode float as int")
 	}
 }

iter_object.go

@@ -150,7 +150,7 @@ func (iter *Iterator) ReadObjectCB(callback func(*Iterator, string) bool) bool {
 		if c == '}' {
 			return iter.decrementDepth()
 		}
-		iter.ReportError("ReadObjectCB", `expect " after }, but found `+string([]byte{c}))
+		iter.ReportError("ReadObjectCB", `expect " after {, but found `+string([]byte{c}))
 		iter.decrementDepth()
 		return false
 	}
@@ -206,7 +206,7 @@ func (iter *Iterator) ReadMapCB(callback func(*Iterator, string) bool) bool {
 		if c == '}' {
 			return iter.decrementDepth()
 		}
-		iter.ReportError("ReadMapCB", `expect " after }, but found `+string([]byte{c}))
+		iter.ReportError("ReadMapCB", `expect " after {, but found `+string([]byte{c}))
 		iter.decrementDepth()
 		return false
 	}

misc_tests/jsoniter_int_test.go

@@ -5,7 +5,9 @@ package misc_tests
 import (
 	"bytes"
 	"encoding/json"
+	"io"
 	"io/ioutil"
+	"math/rand"
 	"strconv"
 	"testing"
 
@@ -70,6 +72,95 @@ func Test_float_as_int(t *testing.T) {
 	should.NotNil(jsoniter.Unmarshal([]byte(`1.1`), &i))
 }
 
+// chunkedData is io.Reader which returns random amount of data in range [1, chunkedData.chunkSize].
+// It simulates chunked data on from HTTP server, which is commonly used by net/http package.
+type chunkedData struct {
+	chunkSize int
+	data      []byte
+	head      int
+}
+
+// Read is implementation of the io.Reader which returns random amount of data in range [1, chunkedData.chunkSize].
+func (c *chunkedData) Read(p []byte) (n int, err error) {
+	to := c.head + int(rand.Int31n(int32(c.chunkSize))+1)
+
+	// copy does not copy more data then p can consume
+	n = copy(p, c.data[c.head:to])
+	c.head = c.head + n
+	if c.head >= len(c.data) {
+		err = io.EOF
+	}
+	return n, err
+}
+
+// TestIterator_ReadInt_chunkedInput validates the behaviour of Iterator.ReadInt() method in where:
+// - it reads data from io.Reader,
+// - expected value is 0 (zero)
+// - Iterator.tail == Iterator.head
+// - Iterator.tail < len(Iterator.buf)
+// - value in buffer after Iterator.tail is presented from previous read and has '.' character.
+func TestIterator_ReadInt_chunkedInput(t *testing.T) {
+	should := require.New(t)
+
+	data := &chunkedData{
+		data: jsonFloatIntArray(t, 10),
+	}
+
+	// because this test is rely on randomness of chunkedData, we are doing multiple iterations to
+	// be sure, that we can hit a required case.
+	for data.chunkSize = 3; data.chunkSize <= len(data.data); data.chunkSize++ {
+		data.head = 0
+
+		iter := jsoniter.Parse(jsoniter.ConfigDefault, data, data.chunkSize)
+		i := 0
+		for iter.ReadArray() {
+			// every even item is float, let's just skip it.
+			if i%2 == 0 {
+				iter.Skip()
+				i++
+				continue
+			}
+
+			should.Zero(iter.ReadInt())
+			should.NoError(iter.Error)
+
+			i++
+		}
+	}
+}
+
+// jsonFloatIntArray generates JSON array where every
+//  - even item is float 0.1
+//  - odd item is integer 0
+//
+//  [0.1, 0, 0.1, 0]
+func jsonFloatIntArray(t *testing.T, numberOfItems int) []byte {
+	t.Helper()
+	numbers := make([]jsoniter.Any, numberOfItems)
+	for i := range numbers {
+		switch i % 2 {
+		case 0:
+			numbers[i] = jsoniter.WrapFloat64(0.1)
+		default:
+			numbers[i] = jsoniter.WrapInt64(0)
+		}
+	}
+
+	fixture, err := jsoniter.ConfigFastest.Marshal(numbers)
+	if err != nil {
+		panic(err)
+	}
+
+	b := &bytes.Buffer{}
+
+	require.NoError(
+		t,
+		json.Compact(b, fixture),
+		"json should be compactable",
+	)
+	return b.Bytes()
+}
+
 func Benchmark_jsoniter_encode_int(b *testing.B) {
 	stream := jsoniter.NewStream(jsoniter.ConfigDefault, ioutil.Discard, 64)
 	for n := 0; n < b.N; n++ {

misc_tests/jsoniter_object_test.go

@@ -2,6 +2,7 @@ package misc_tests
 
 import (
 	"bytes"
+	"reflect"
 	"testing"
 
 	"github.com/json-iterator/go"
@@ -147,3 +148,225 @@ func Test_unmarshal_into_existing_value(t *testing.T) {
 		"k": "v",
 	}, m)
 }
+
+// for issue421
+func Test_unmarshal_anonymous_struct_invalid(t *testing.T) {
+	should := require.New(t)
+	t0 := struct {
+		Field1 string
+	}{}
+
+	cfg := jsoniter.ConfigCompatibleWithStandardLibrary
+	err := cfg.UnmarshalFromString(`{"Field1":`, &t0)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t0).String())
+
+	cfgCaseSensitive := jsoniter.Config{
+		CaseSensitive: true,
+	}.Froze()
+
+	type TestObject1 struct {
+		Field1 struct {
+			InnerField1 string
+		}
+	}
+	t1 := TestObject1{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field1":{"InnerField1"`, &t1)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t1.Field1).String())
+	should.Contains(err.Error(), reflect.TypeOf(t1).String())
+
+	type TestObject2 struct {
+		Field1 int
+		Field2 struct {
+			InnerField1 string
+			InnerField2 string
+		}
+	}
+	t2 := TestObject2{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field2":{"InnerField2"`, &t2)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t2.Field2).String())
+	should.Contains(err.Error(), reflect.TypeOf(t2).String())
+
+	type TestObject3 struct {
+		Field1 int
+		Field2 int
+		Field3 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+		}
+	}
+	t3 := TestObject3{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field3":{"InnerField3"`, &t3)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t3.Field3).String())
+	should.Contains(err.Error(), reflect.TypeOf(t3).String())
+
+	type TestObject4 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+		}
+	}
+	t4 := TestObject4{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field4":{"InnerField4"`, &t4)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t4.Field4).String())
+	should.Contains(err.Error(), reflect.TypeOf(t4).String())
+
+	type TestObject5 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 int
+		Field5 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+			InnerField5 string
+		}
+	}
+	t5 := TestObject5{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field5":{"InnerField5"`, &t5)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t5.Field5).String())
+	should.Contains(err.Error(), reflect.TypeOf(t5).String())
+
+	type TestObject6 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 int
+		Field5 int
+		Field6 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+			InnerField5 string
+			InnerField6 string
+		}
+	}
+	t6 := TestObject6{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field6":{"InnerField6"`, &t6)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t6.Field6).String())
+	should.Contains(err.Error(), reflect.TypeOf(t6).String())
+
+	type TestObject7 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 int
+		Field5 int
+		Field6 int
+		Field7 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+			InnerField5 string
+			InnerField6 string
+			InnerField7 string
+		}
+	}
+	t7 := TestObject7{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field7":{"InnerField7"`, &t7)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t7.Field7).String())
+	should.Contains(err.Error(), reflect.TypeOf(t7).String())
+
+	type TestObject8 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 int
+		Field5 int
+		Field6 int
+		Field7 int
+		Field8 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+			InnerField5 string
+			InnerField6 string
+			InnerField7 string
+			InnerField8 string
+		}
+	}
+	t8 := TestObject8{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field8":{"InnerField8"`, &t8)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t8.Field8).String())
+	should.Contains(err.Error(), reflect.TypeOf(t8).String())
+
+	type TestObject9 struct {
+		Field1 int
+		Field2 int
+		Field3 int
+		Field4 int
+		Field5 int
+		Field6 int
+		Field7 int
+		Field8 int
+		Field9 struct {
+			InnerField1 string
+			InnerField2 string
+			InnerField3 string
+			InnerField4 string
+			InnerField5 string
+			InnerField6 string
+			InnerField7 string
+			InnerField8 string
+			InnerField9 string
+		}
+	}
+	t9 := TestObject9{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field9":{"InnerField9"`, &t9)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t9.Field9).String())
+	should.Contains(err.Error(), reflect.TypeOf(t9).String())
+
+	type TestObject10 struct {
+		Field1  int
+		Field2  int
+		Field3  int
+		Field4  int
+		Field5  int
+		Field6  int
+		Field7  int
+		Field8  int
+		Field9  int
+		Field10 struct {
+			InnerField1  string
+			InnerField2  string
+			InnerField3  string
+			InnerField4  string
+			InnerField5  string
+			InnerField6  string
+			InnerField7  string
+			InnerField8  string
+			InnerField9  string
+			InnerField10 string
+		}
+	}
+	t10 := TestObject10{}
+	err = cfgCaseSensitive.UnmarshalFromString(`{"Field10":{"InnerField10"`, &t10)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t10.Field10).String())
+	should.Contains(err.Error(), reflect.TypeOf(t10).String())
+
+	err = cfg.UnmarshalFromString(`{"Field10":{"InnerField10"`, &t10)
+	should.NotNil(err)
+	should.NotContains(err.Error(), reflect.TypeOf(t10.Field10).String())
+	should.Contains(err.Error(), reflect.TypeOf(t10).String())
+}

misc_tests/jsoniter_raw_message_test.go

@@ -42,6 +42,25 @@ func Test_marshal_invalid_json_raw_message(t *testing.T) {
 	should.Nil(aouterr)
 }
 
+func Test_marshal_nil_json_raw_message(t *testing.T) {
+	type A struct {
+		Nil1 jsoniter.RawMessage `json:"raw1"`
+		Nil2 json.RawMessage     `json:"raw2"`
+	}
+
+	a := A{}
+	should := require.New(t)
+	aout, aouterr := jsoniter.Marshal(&a)
+	should.Equal(`{"raw1":null,"raw2":null}`, string(aout))
+	should.Nil(aouterr)
+
+	a.Nil1 = []byte(`Any`)
+	a.Nil2 = []byte(`Any`)
+	should.Nil(jsoniter.Unmarshal(aout, &a))
+	should.Nil(a.Nil1)
+	should.Nil(a.Nil2)
+}
+
 func Test_raw_message_memory_not_copied_issue(t *testing.T) {
 	jsonStream := `{"name":"xxxxx","bundle_id":"com.zonst.majiang","app_platform":"ios","app_category":"100103", "budget_day":1000,"bidding_min":1,"bidding_max":2,"bidding_type":"CPM", "freq":{"open":true,"type":"day","num":100},"speed":1, "targeting":{"vendor":{"open":true,"list":["zonst"]}, "geo_code":{"open":true,"list":["156110100"]},"app_category":{"open":true,"list":["100101"]}, "day_parting":{"open":true,"list":["100409","100410"]},"device_type":{"open":true,"list":["ipad"]}, "os_version":{"open":true,"list":[10]},"carrier":{"open":true,"list":["mobile"]}, "network":{"open":true,"list":["4G"]}},"url":{"tracking_imp_url":"http://www.baidu.com", "tracking_clk_url":"http://www.baidu.com","jump_url":"http://www.baidu.com","deep_link_url":"http://www.baidu.com"}}`
 	type IteratorObject struct {

reflect.go

@@ -65,7 +65,7 @@ func (iter *Iterator) ReadVal(obj interface{}) {
 	decoder := iter.cfg.getDecoderFromCache(cacheKey)
 	if decoder == nil {
 		typ := reflect2.TypeOf(obj)
-		if typ.Kind() != reflect.Ptr {
+		if typ == nil || typ.Kind() != reflect.Ptr {
 			iter.ReportError("ReadVal", "can only unmarshal into pointer")
 			return
 		}

reflect_extension.go

@@ -475,7 +475,7 @@ func calcFieldNames(originalFieldName string, tagProvidedFieldName string, whole
 		fieldNames = []string{tagProvidedFieldName}
 	}
 	// private?
-	isNotExported := unicode.IsLower(rune(originalFieldName[0]))
+	isNotExported := unicode.IsLower(rune(originalFieldName[0])) || originalFieldName[0] == '_'
 	if isNotExported {
 		fieldNames = []string{}
 	}

reflect_json_raw_message.go

@@ -33,11 +33,19 @@ type jsonRawMessageCodec struct {
 }
 
 func (codec *jsonRawMessageCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*json.RawMessage)(ptr)) = json.RawMessage(iter.SkipAndReturnBytes())
+	if iter.ReadNil() {
+		*((*json.RawMessage)(ptr)) = nil
+	} else {
+		*((*json.RawMessage)(ptr)) = iter.SkipAndReturnBytes()
+	}
 }
 
 func (codec *jsonRawMessageCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
-	stream.WriteRaw(string(*((*json.RawMessage)(ptr))))
+	if *((*json.RawMessage)(ptr)) == nil {
+		stream.WriteNil()
+	} else {
+		stream.WriteRaw(string(*((*json.RawMessage)(ptr))))
+	}
 }
 
 func (codec *jsonRawMessageCodec) IsEmpty(ptr unsafe.Pointer) bool {
@@ -48,11 +56,19 @@ type jsoniterRawMessageCodec struct {
 }
 
 func (codec *jsoniterRawMessageCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*RawMessage)(ptr)) = RawMessage(iter.SkipAndReturnBytes())
+	if iter.ReadNil() {
+		*((*RawMessage)(ptr)) = nil
+	} else {
+		*((*RawMessage)(ptr)) = iter.SkipAndReturnBytes()
+	}
 }
 
 func (codec *jsoniterRawMessageCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
-	stream.WriteRaw(string(*((*RawMessage)(ptr))))
+	if *((*RawMessage)(ptr)) == nil {
+		stream.WriteNil()
+	} else {
+		stream.WriteRaw(string(*((*RawMessage)(ptr))))
+	}
 }
 
 func (codec *jsoniterRawMessageCodec) IsEmpty(ptr unsafe.Pointer) bool {

reflect_map.go

@@ -49,6 +49,33 @@ func decoderOfMapKey(ctx *ctx, typ reflect2.Type) ValDecoder {
 			return decoder
 		}
 	}
+
+	ptrType := reflect2.PtrTo(typ)
+	if ptrType.Implements(unmarshalerType) {
+		return &referenceDecoder{
+			&unmarshalerDecoder{
+				valType: ptrType,
+			},
+		}
+	}
+	if typ.Implements(unmarshalerType) {
+		return &unmarshalerDecoder{
+			valType: typ,
+		}
+	}
+	if ptrType.Implements(textUnmarshalerType) {
+		return &referenceDecoder{
+			&textUnmarshalerDecoder{
+				valType: ptrType,
+			},
+		}
+	}
+	if typ.Implements(textUnmarshalerType) {
+		return &textUnmarshalerDecoder{
+			valType: typ,
+		}
+	}
+
 	switch typ.Kind() {
 	case reflect.String:
 		return decoderOfType(ctx, reflect2.DefaultTypeOfKind(reflect.String))
@@ -63,31 +90,6 @@ func decoderOfMapKey(ctx *ctx, typ reflect2.Type) ValDecoder {
 		typ = reflect2.DefaultTypeOfKind(typ.Kind())
 		return &numericMapKeyDecoder{decoderOfType(ctx, typ)}
 	default:
-		ptrType := reflect2.PtrTo(typ)
-		if ptrType.Implements(unmarshalerType) {
-			return &referenceDecoder{
-				&unmarshalerDecoder{
-					valType: ptrType,
-				},
-			}
-		}
-		if typ.Implements(unmarshalerType) {
-			return &unmarshalerDecoder{
-				valType: typ,
-			}
-		}
-		if ptrType.Implements(textUnmarshalerType) {
-			return &referenceDecoder{
-				&textUnmarshalerDecoder{
-					valType: ptrType,
-				},
-			}
-		}
-		if typ.Implements(textUnmarshalerType) {
-			return &textUnmarshalerDecoder{
-				valType: typ,
-			}
-		}
 		return &lazyErrorDecoder{err: fmt.Errorf("unsupported map key type: %v", typ)}
 	}
 }
@@ -103,6 +105,19 @@ func encoderOfMapKey(ctx *ctx, typ reflect2.Type) ValEncoder {
 			return encoder
 		}
 	}
+
+	if typ == textMarshalerType {
+		return &directTextMarshalerEncoder{
+			stringEncoder: ctx.EncoderOf(reflect2.TypeOf("")),
+		}
+	}
+	if typ.Implements(textMarshalerType) {
+		return &textMarshalerEncoder{
+			valType:       typ,
+			stringEncoder: ctx.EncoderOf(reflect2.TypeOf("")),
+		}
+	}
+
 	switch typ.Kind() {
 	case reflect.String:
 		return encoderOfType(ctx, reflect2.DefaultTypeOfKind(reflect.String))
@@ -117,17 +132,6 @@ func encoderOfMapKey(ctx *ctx, typ reflect2.Type) ValEncoder {
 		typ = reflect2.DefaultTypeOfKind(typ.Kind())
 		return &numericMapKeyEncoder{encoderOfType(ctx, typ)}
 	default:
-		if typ == textMarshalerType {
-			return &directTextMarshalerEncoder{
-				stringEncoder: ctx.EncoderOf(reflect2.TypeOf("")),
-			}
-		}
-		if typ.Implements(textMarshalerType) {
-			return &textMarshalerEncoder{
-				valType:       typ,
-				stringEncoder: ctx.EncoderOf(reflect2.TypeOf("")),
-			}
-		}
 		if typ.Kind() == reflect.Interface {
 			return &dynamicMapKeyEncoder{ctx, typ}
 		}
@@ -163,10 +167,6 @@ func (decoder *mapDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
 	if c == '}' {
 		return
 	}
-	if c != '"' {
-		iter.ReportError("ReadMapCB", `expect " after }, but found `+string([]byte{c}))
-		return
-	}
 	iter.unreadByte()
 	key := decoder.keyType.UnsafeNew()
 	decoder.keyDecoder.Decode(key, iter)

reflect_optional.go

@@ -2,7 +2,6 @@ package jsoniter
 
 import (
 	"github.com/modern-go/reflect2"
-	"reflect"
 	"unsafe"
 )
 
@@ -10,9 +9,6 @@ func decoderOfOptional(ctx *ctx, typ reflect2.Type) ValDecoder {
 	ptrType := typ.(*reflect2.UnsafePtrType)
 	elemType := ptrType.Elem()
 	decoder := decoderOfType(ctx, elemType)
-	if ctx.prefix == "" && elemType.Kind() == reflect.Ptr {
-		return &dereferenceDecoder{elemType, decoder}
-	}
 	return &OptionalDecoder{elemType, decoder}
 }
 

reflect_struct_decoder.go

@@ -507,7 +507,7 @@ func (decoder *generalStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator)
 	for c = ','; c == ','; c = iter.nextToken() {
 		decoder.decodeOneField(ptr, iter)
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	if c != '}' {
@@ -588,7 +588,7 @@ func (decoder *oneFieldStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator)
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -622,7 +622,7 @@ func (decoder *twoFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -660,7 +660,7 @@ func (decoder *threeFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterat
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -702,7 +702,7 @@ func (decoder *fourFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterato
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -748,7 +748,7 @@ func (decoder *fiveFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterato
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -798,7 +798,7 @@ func (decoder *sixFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -852,7 +852,7 @@ func (decoder *sevenFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterat
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -910,7 +910,7 @@ func (decoder *eightFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterat
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -972,7 +972,7 @@ func (decoder *nineFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterato
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -1038,7 +1038,7 @@ func (decoder *tenFieldsStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator
 			break
 		}
 	}
-	if iter.Error != nil && iter.Error != io.EOF {
+	if iter.Error != nil && iter.Error != io.EOF && len(decoder.typ.Type1().Name()) != 0 {
 		iter.Error = fmt.Errorf("%v.%s", decoder.typ, iter.Error.Error())
 	}
 	iter.decrementDepth()
@@ -1075,6 +1075,11 @@ type stringModeNumberDecoder struct {
 }
 
 func (decoder *stringModeNumberDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
+	if iter.WhatIsNext() == NilValue {
+		decoder.elemDecoder.Decode(ptr, iter)
+		return
+	}
+
 	c := iter.nextToken()
 	if c != '"' {
 		iter.ReportError("stringModeNumberDecoder", `expect ", but found `+string([]byte{c}))

stream.go

@@ -103,14 +103,14 @@ func (stream *Stream) Flush() error {
 	if stream.Error != nil {
 		return stream.Error
 	}
-	n, err := stream.out.Write(stream.buf)
+	_, err := stream.out.Write(stream.buf)
 	if err != nil {
 		if stream.Error == nil {
 			stream.Error = err
 		}
 		return err
 	}
-	stream.buf = stream.buf[n:]
+	stream.buf = stream.buf[:0]
 	return nil
 }
 
@@ -177,7 +177,6 @@ func (stream *Stream) WriteEmptyObject() {
 func (stream *Stream) WriteMore() {
 	stream.writeByte(',')
 	stream.writeIndention(0)
-	stream.Flush()
 }
 
 // WriteArrayStart write [ with possible indention

stream_test.go

@@ -1,8 +1,9 @@
 package jsoniter
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func Test_writeByte_should_grow_buffer(t *testing.T) {
@@ -62,8 +63,24 @@ func (w *NopWriter) Write(p []byte) (n int, err error) {
 }
 
 func Test_flush_buffer_should_stop_grow_buffer(t *testing.T) {
+	// Stream an array of a zillion zeros.
 	writer := new(NopWriter)
-	NewEncoder(writer).Encode(make([]int, 10000000))
+	stream := NewStream(ConfigDefault, writer, 512)
+	stream.WriteArrayStart()
+	for i := 0; i < 10000000; i++ {
+		stream.WriteInt(0)
+		stream.WriteMore()
+		stream.Flush()
+	}
+	stream.WriteInt(0)
+	stream.WriteArrayEnd()
+
+	// Confirm that the buffer didn't have to grow.
 	should := require.New(t)
-	should.Equal(8, writer.bufferSize)
+
+	// 512 is the internal buffer size set in NewEncoder
+	//
+	// Flush is called after each array element, so only the first 8 bytes of it
+	// is ever used, and it is never extended. Capacity remains 512.
+	should.Equal(512, writer.bufferSize)
 }

type_tests/map_key_test.go

@@ -1,3 +1,7 @@
+// +build go1.15
+// remove these tests temporarily until https://github.com/golang/go/issues/38105 and
+// https://github.com/golang/go/issues/38940 is fixed
+
 package test
 
 import (

type_tests/struct_tags_test.go

@@ -121,10 +121,11 @@ func init() {
 			F1 int32 `json:"F1"`
 			F2 int32 `json:"F2,string"`
 		})(nil),
-		(*struct {
-			F1 string `json:"F1"`
-			F2 string `json:"F2,string"`
-		})(nil),
+		// remove temporarily until https://github.com/golang/go/issues/38126 is fixed
+		// (*struct {
+		// 	F1 string `json:"F1"`
+		// 	F2 string `json:"F2,string"`
+		// })(nil),
 		(*struct {
 			F1 uint8 `json:"F1"`
 			F2 uint8 `json:"F2,string"`

value_tests/map_test.go

@@ -31,6 +31,7 @@ func init() {
 		map[string]*json.RawMessage{"hello": pRawMessage(json.RawMessage("[]"))},
 		map[Date]bool{{}: true},
 		map[Date2]bool{{}: true},
+		map[customKey]string{customKey(1): "bar"},
 	)
 	unmarshalCases = append(unmarshalCases, unmarshalCase{
 		ptr:   (*map[string]string)(nil),
@@ -55,6 +56,9 @@ func init() {
         "2018-12-13": true,
         "2018-12-14": true
     	}`,
+	}, unmarshalCase{
+		ptr: (*map[customKey]string)(nil),
+		input: `{"foo": "bar"}`,
 	})
 }
 
@@ -115,3 +119,14 @@ func (d Date2) UnmarshalJSON(b []byte) error {
 func (d Date2) MarshalJSON() ([]byte, error) {
 	return []byte(d.Time.Format("2006-01-02")), nil
 }
+
+type customKey int32
+
+func (c customKey) MarshalText() ([]byte, error) {
+	return []byte("foo"), nil
+}
+
+func (c *customKey) UnmarshalText(value []byte) error {
+	*c = 1
+	return nil
+}

value_tests/ptr_114_test.go

@@ -0,0 +1,15 @@
+// +build go1.14
+
+package test
+
+func init() {
+	unmarshalCases = append(unmarshalCases, unmarshalCase{
+		obj: func() interface{} {
+			var i int
+			pi := &i
+			ppi := &pi
+			return &ppi
+		},
+		input: "null",
+	})
+}

value_tests/ptr_test.go

@@ -27,13 +27,5 @@ func init() {
 			return &pi
 		},
 		input: "null",
-	}, unmarshalCase{
-		obj: func() interface{} {
-			var i int
-			pi := &i
-			ppi := &pi
-			return &ppi
-		},
-		input: "null",
 	})
 }

value_tests/raw_message_test.go

@@ -7,6 +7,9 @@ import (
 func init() {
 	marshalCases = append(marshalCases,
 		json.RawMessage("{}"),
+		json.RawMessage("12345"),
+		json.RawMessage("3.14"),
+		json.RawMessage("-0.5e10"),
 		struct {
 			Env   string          `json:"env"`
 			Extra json.RawMessage `json:"extra,omitempty"`

value_tests/struct_test.go

@@ -26,6 +26,11 @@ func init() {
 			Field int `json:"field"`
 		})(nil),
 		input: `{"field": null}`,
+	}, unmarshalCase{
+		ptr: (*struct {
+			Field int `json:"field,string"`
+		})(nil),
+		input: `{"field": null}`,
 	}, unmarshalCase{
 		ptr: (*struct {
 			ID      int                    `json:"id"`
@@ -194,6 +199,11 @@ func init() {
 			C: 21,
 			d: time.NewTimer(10 * time.Second),
 		},
+		struct {
+			_UnderscoreField string
+		}{
+			"should not marshal",
+		},
 	)
 }