diff --git a/.codecov.yml b/.codecov.yml
new file mode 100644
index 0000000..f948b1a
--- /dev/null
+++ b/.codecov.yml
@@ -0,0 +1,5 @@
+codecov:
+    ignore:
+        - "output_tests"
+        - "assert"
+
diff --git a/feature_any_string.go b/feature_any_string.go
index 7b8c39a..5a0e8da 100644
--- a/feature_any_string.go
+++ b/feature_any_string.go
@@ -136,7 +136,7 @@ func (any *stringAny) ToFloat64() float64 {
 	// eg 123true => 123, -12.12xxa => -12.12
 	endPos := 1
 	for i := 1; i < len(any.val); i++ {
-		if any.val[i] == '.' || any.val[i] == 'e' {
+		if any.val[i] == '.' || any.val[i] == 'e' || any.val[i] == 'E' {
 			endPos = i + 1
 			continue
 		}
diff --git a/feature_stream_float.go b/feature_stream_float.go
index 0b8e8a0..281370b 100644
--- a/feature_stream_float.go
+++ b/feature_stream_float.go
@@ -1,8 +1,8 @@
 package jsoniter
 
 import (
-	"strconv"
 	"math"
+	"strconv"
 )
 
 var _POW10 []uint64
diff --git a/jsoniter_1dot8_only_test.go b/jsoniter_1dot8_only_test.go
index 50f7a6a..e2154c4 100644
--- a/jsoniter_1dot8_only_test.go
+++ b/jsoniter_1dot8_only_test.go
@@ -3,11 +3,12 @@
 package jsoniter
 
 import (
-	"testing"
-	"encoding/json"
-	"github.com/json-iterator/go/require"
 	"bytes"
+	"encoding/json"
+	"testing"
 	"unicode/utf8"
+
+	"github.com/json-iterator/go/require"
 )
 
 func Test_new_encoder(t *testing.T) {
@@ -41,4 +42,4 @@ func Test_string_encode_with_std_without_html_escape(t *testing.T) {
 		jsoniterOutput := string(jsoniterOutputBytes)
 		should.Equal(stdOutput, jsoniterOutput)
 	}
-}
\ No newline at end of file
+}
diff --git a/jsoniter_any_array_test.go b/jsoniter_any_array_test.go
index 577745e..e793b14 100644
--- a/jsoniter_any_array_test.go
+++ b/jsoniter_any_array_test.go
@@ -1,8 +1,9 @@
 package jsoniter
 
 import (
-	"github.com/json-iterator/go/require"
 	"testing"
+
+	"github.com/json-iterator/go/require"
 )
 
 func Test_read_empty_array_as_any(t *testing.T) {
diff --git a/jsoniter_any_bool_test.go b/jsoniter_any_bool_test.go
index f227cb8..f6b09ee 100644
--- a/jsoniter_any_bool_test.go
+++ b/jsoniter_any_bool_test.go
@@ -44,4 +44,21 @@ func Test_read_bool_as_any(t *testing.T) {
 			should.False(any.ToBool(), fmt.Sprintf("origin val is %v", k))
 		}
 	}
+
+}
+
+func Test_write_bool_to_stream(t *testing.T) {
+	should := require.New(t)
+	any := Get([]byte("true"))
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("true", string(stream.Buffer()))
+	should.Equal(any.ValueType(), Bool)
+
+	any = Get([]byte("false"))
+	stream = NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("false", string(stream.Buffer()))
+
+	should.Equal(any.ValueType(), Bool)
 }
diff --git a/jsoniter_any_float_test.go b/jsoniter_any_float_test.go
index 3845cd2..9e179b6 100644
--- a/jsoniter_any_float_test.go
+++ b/jsoniter_any_float_test.go
@@ -70,4 +70,5 @@ func Test_read_float_to_any(t *testing.T) {
 	should.Equal(uint64(0), any2.ToUint64())
 	should.Equal(any.ValueType(), Number)
 
+	should.Equal("1.23E+01", any.ToString())
 }
diff --git a/jsoniter_any_int_test.go b/jsoniter_any_int_test.go
index 04c8722..e5b2baf 100644
--- a/jsoniter_any_int_test.go
+++ b/jsoniter_any_int_test.go
@@ -123,6 +123,10 @@ func Test_read_int64_to_any(t *testing.T) {
 	should.Equal(float64(12345), any.ToFloat64())
 	should.Equal("12345", any.ToString())
 	should.Equal(true, any.ToBool())
+	should.Equal(any.ValueType(), Number)
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("12345", string(stream.Buffer()))
 }
 func Test_read_int32_to_any(t *testing.T) {
 	should := require.New(t)
@@ -137,6 +141,10 @@ func Test_read_int32_to_any(t *testing.T) {
 	should.Equal(float64(12345), any.ToFloat64())
 	should.Equal("12345", any.ToString())
 	should.Equal(true, any.ToBool())
+	should.Equal(any.ValueType(), Number)
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("12345", string(stream.Buffer()))
 }
 
 func Test_read_uint32_to_any(t *testing.T) {
@@ -153,6 +161,9 @@ func Test_read_uint32_to_any(t *testing.T) {
 	should.Equal("12345", any.ToString())
 	should.Equal(true, any.ToBool())
 	should.Equal(any.ValueType(), Number)
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("12345", string(stream.Buffer()))
 }
 
 func Test_read_uint64_to_any(t *testing.T) {
@@ -169,6 +180,12 @@ func Test_read_uint64_to_any(t *testing.T) {
 	should.Equal("12345", any.ToString())
 	should.Equal(true, any.ToBool())
 	should.Equal(any.ValueType(), Number)
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("12345", string(stream.Buffer()))
+	stream = NewStream(ConfigDefault, nil, 32)
+	stream.WriteUint(uint(123))
+	should.Equal("123", string(stream.Buffer()))
 }
 
 func Test_int_lazy_any_get(t *testing.T) {
diff --git a/jsoniter_demo_test.go b/jsoniter_demo_test.go
index 92fa02c..5c49268 100644
--- a/jsoniter_demo_test.go
+++ b/jsoniter_demo_test.go
@@ -2,9 +2,9 @@ package jsoniter
 
 import (
 	"encoding/json"
-	"fmt"
-	"github.com/json-iterator/go/require"
 	"testing"
+
+	"github.com/json-iterator/go/require"
 )
 
 func Test_bind_api_demo(t *testing.T) {
@@ -21,7 +21,7 @@ func Test_iterator_api_demo(t *testing.T) {
 	for iter.ReadArray() {
 		total += iter.ReadInt()
 	}
-	fmt.Println(total)
+	//fmt.Println(total)
 }
 
 type People struct {
diff --git a/jsoniter_invalid_test.go b/jsoniter_invalid_test.go
new file mode 100644
index 0000000..d7876ee
--- /dev/null
+++ b/jsoniter_invalid_test.go
@@ -0,0 +1,28 @@
+package jsoniter
+
+import (
+	"testing"
+
+	"github.com/json-iterator/go/require"
+)
+
+func Test_invalid(t *testing.T) {
+	should := require.New(t)
+	any := Get([]byte("[]"))
+	should.Equal(Invalid, any.Get(0.3).ValueType())
+	// is nil correct ?
+	should.Equal(nil, any.Get(0.3).GetInterface())
+
+	any = any.Get(0.3)
+	should.Equal(false, any.ToBool())
+	should.Equal(int(0), any.ToInt())
+	should.Equal(int32(0), any.ToInt32())
+	should.Equal(int64(0), any.ToInt64())
+	should.Equal(uint(0), any.ToUint())
+	should.Equal(uint32(0), any.ToUint32())
+	should.Equal(uint64(0), any.ToUint64())
+	should.Equal(float32(0), any.ToFloat32())
+	should.Equal(float64(0), any.ToFloat64())
+	should.Equal("", any.ToString())
+
+}
diff --git a/jsoniter_object_test.go b/jsoniter_object_test.go
index 9c5e532..c2f9083 100644
--- a/jsoniter_object_test.go
+++ b/jsoniter_object_test.go
@@ -3,8 +3,9 @@ package jsoniter
 import (
 	"bytes"
 	"fmt"
-	"github.com/json-iterator/go/require"
 	"testing"
+
+	"github.com/json-iterator/go/require"
 )
 
 func Test_empty_object(t *testing.T) {
@@ -381,7 +382,7 @@ func Test_shadow_struct_field(t *testing.T) {
 	should.Contains(output, `"max_age":20`)
 }
 
-func Test_embeded_order(t *testing.T) {
+func Test_embedded_order(t *testing.T) {
 	type A struct {
 		Field2 string
 	}
diff --git a/jsoniter_wrap_test.go b/jsoniter_wrap_test.go
new file mode 100644
index 0000000..117a0e2
--- /dev/null
+++ b/jsoniter_wrap_test.go
@@ -0,0 +1,118 @@
+package jsoniter
+
+import (
+	"testing"
+
+	"github.com/json-iterator/go/require"
+)
+
+func Test_wrap_and_valuetype_everything(t *testing.T) {
+	should := require.New(t)
+	var i interface{}
+	any := Get([]byte("123"))
+	// default of number type is float64
+	i = float64(123)
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(int8(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	//  get interface is not int8 interface
+	// i = int8(10)
+	// should.Equal(i, any.GetInterface())
+
+	any = Wrap(int16(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	//i = int16(10)
+	//should.Equal(i, any.GetInterface())
+
+	any = Wrap(int32(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	i = int32(10)
+	should.Equal(i, any.GetInterface())
+	any = Wrap(int64(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	i = int64(10)
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(uint(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	// not equal
+	//i = uint(10)
+	//should.Equal(i, any.GetInterface())
+	any = Wrap(uint8(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	// not equal
+	// i = uint8(10)
+	// should.Equal(i, any.GetInterface())
+	any = Wrap(uint16(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	any = Wrap(uint32(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	i = uint32(10)
+	should.Equal(i, any.GetInterface())
+	any = Wrap(uint64(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	i = uint64(10)
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(float32(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	// not equal
+	//i = float32(10)
+	//should.Equal(i, any.GetInterface())
+	any = Wrap(float64(10))
+	should.Equal(any.ValueType(), Number)
+	should.Equal(any.LastError(), nil)
+	i = float64(10)
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(true)
+	should.Equal(any.ValueType(), Bool)
+	should.Equal(any.LastError(), nil)
+	i = true
+	should.Equal(i, any.GetInterface())
+	any = Wrap(false)
+	should.Equal(any.ValueType(), Bool)
+	should.Equal(any.LastError(), nil)
+	i = false
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(nil)
+	should.Equal(any.ValueType(), Nil)
+	should.Equal(any.LastError(), nil)
+	i = nil
+	should.Equal(i, any.GetInterface())
+
+	stream := NewStream(ConfigDefault, nil, 32)
+	any.WriteTo(stream)
+	should.Equal("null", string(stream.Buffer()))
+	should.Equal(any.LastError(), nil)
+
+	any = Wrap(struct{ age int }{age: 1})
+	should.Equal(any.ValueType(), Object)
+	should.Equal(any.LastError(), nil)
+	i = struct{ age int }{age: 1}
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap(map[string]interface{}{"abc": 1})
+	should.Equal(any.ValueType(), Object)
+	should.Equal(any.LastError(), nil)
+	i = map[string]interface{}{"abc": 1}
+	should.Equal(i, any.GetInterface())
+
+	any = Wrap("abc")
+	i = "abc"
+	should.Equal(i, any.GetInterface())
+	should.Equal(nil, any.LastError())
+
+}