diff --git a/context_test.go b/context_test.go
index 05f4994..f420a3c 100644
--- a/context_test.go
+++ b/context_test.go
@@ -823,3 +823,26 @@ func TestPipe(t *testing.T) {
 	assert.Equal(int64(len(data)), written)
 	assert.Equal(data, resp.Body.Bytes())
 }
+
+func TestContextGetTrace(t *testing.T) {
+	assert := assert.New(t)
+	req, err := http.NewRequest("GET", "/", nil)
+	assert.Nil(err)
+	c := NewContext(nil, req)
+	assert.NotNil(c.GetTrace())
+}
+
+func TestContextIsContext(t *testing.T) {
+	assert := assert.New(t)
+	req, err := http.NewRequest("GET", "/", nil)
+	assert.Nil(err)
+	c := NewContext(nil, req)
+
+	_, ok := c.Deadline()
+	assert.False(ok)
+
+	assert.Nil(c.Done())
+	assert.Nil(c.Err())
+
+	assert.Nil(c.Value("abc"))
+}
diff --git a/elton_test.go b/elton_test.go
index 3d591b2..6ec1fda 100644
--- a/elton_test.go
+++ b/elton_test.go
@@ -397,6 +397,10 @@ func TestOnError(t *testing.T) {
 		assert.Equal(customErr, err)
 	})
 	e.EmitError(c, customErr)
+	req, err := http.NewRequest("GET", "/", nil)
+	assert.Nil(err)
+
+	e.emitError(httptest.NewRecorder(), req, customErr)
 }
 
 func TestOnTrace(t *testing.T) {
diff --git a/go.mod b/go.mod
index 580966f..019dd37 100644
--- a/go.mod
+++ b/go.mod
@@ -15,6 +15,6 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
-	github.com/tidwall/pretty v1.2.1 // indirect
+	github.com/tidwall/pretty v1.2.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index e714564..0a6d402 100644
--- a/go.sum
+++ b/go.sum
@@ -18,9 +18,8 @@ github.com/tidwall/gjson v1.14.4 h1:uo0p8EbA09J7RQaflQ1aBRffTR7xedD2bcIVSYxLnkM=
 github.com/tidwall/gjson v1.14.4/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
 github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0 h1:RWIZEg2iJ8/g6fDDYzMpobmaoGh5OLl4AXtGUGPcqCs=
 github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
-github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
-github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/vicanso/hes v0.6.1 h1:BRGUDhV2sJYMieJf4dgxFXjvuhDgUWBsINELcti0Z8M=
 github.com/vicanso/hes v0.6.1/go.mod h1:awwBbvcDTk8APxRmiV7Hxrir89/iCxgB6RMeLc5toh0=
 github.com/vicanso/intranet-ip v0.1.0 h1:UeoxilO2VDIkeZZxmu6aT+f5o79mfGdsSdwoEv75nYo=
diff --git a/middleware/compress_test.go b/middleware/compress_test.go
index e7503fb..f0455c8 100644
--- a/middleware/compress_test.go
+++ b/middleware/compress_test.go
@@ -29,7 +29,6 @@ import (
 	"net/http/httptest"
 	"sync/atomic"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/vicanso/elton"
@@ -54,7 +53,6 @@ func (t *testCompressor) Pipe(c *elton.Context) error {
 // randomString get random string
 func randomString(n int) string {
 	b := make([]rune, n)
-	rand.Seed(time.Now().UnixNano())
 	for i := range b {
 		b[i] = letterRunes[rand.Intn(len(letterRunes))]
 	}
diff --git a/multipart_form.go b/multipart_form.go
index 2b35ed0..191cf63 100644
--- a/multipart_form.go
+++ b/multipart_form.go
@@ -36,7 +36,8 @@ type multipartForm struct {
 	contentType string
 }
 
-// NewMultipartForm returns a new multipart form
+// NewMultipartForm returns a new multipart form,
+// the form data will be saved as tmp file for less memory.
 func NewMultipartForm() *multipartForm {
 	return &multipartForm{}
 }
diff --git a/multipart_form_test.go b/multipart_form_test.go
index 8caf41d..1196ec8 100644
--- a/multipart_form_test.go
+++ b/multipart_form_test.go
@@ -44,6 +44,10 @@ func TestMultipartForm(t *testing.T) {
 	err = form.AddFile("file", "test.txt", bytes.NewBufferString("Hello world!"))
 	assert.Nil(err)
 
+	err = form.AddFile("source", "./multipart_form_test.go")
+	assert.Nil(err)
+
+	assert.True(strings.HasPrefix(form.ContentType(), "multipart/form-data; boundary="))
 	r, err := form.Reader()
 	assert.Nil(err)
 	buf, err := io.ReadAll(r)
@@ -54,3 +58,13 @@ func TestMultipartForm(t *testing.T) {
 	assert.True(strings.Contains(str, `Content-Type: application/octet-stream`))
 	assert.True(strings.Contains(str, `Content-Disposition: form-data; name="a"`))
 }
+
+func TestTestMultipartFormDestroy(t *testing.T) {
+	assert := assert.New(t)
+	form := NewMultipartForm()
+	err := form.AddField("a", "1")
+	assert.Nil(err)
+
+	err = form.Destroy()
+	assert.Nil(err)
+}