diff --git a/encode_test.go b/encode_test.go
index b88c8f2..bc4df41 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -30,7 +30,6 @@ import (
 	`unsafe`
 
 	`github.com/bytedance/sonic/encoder`
-	`github.com/stretchr/testify/assert`
 )
 
 type Optionals struct {
@@ -705,7 +704,7 @@ func TestDuplicatedFieldDisappears(t *testing.T) {
 	}
 }
 
-func TestIssue10281(t *testing.T) {
+func TestStdLibIssue10281(t *testing.T) {
 	type Foo struct {
 		N json.Number
 	}
@@ -1129,61 +1128,3 @@ func TestMarshalerError(t *testing.T) {
 		}
 	}
 }
-
-func TestIssue3_Encode(t *testing.T) {
-	var v HugeStruct6
-	ret, err := Marshal(v)
-	assert.Nil(t, err)
-	assert.Equal(t, []byte(`{}`), ret)
-}
-
-func TestIssue3_Decode(t *testing.T) {
-	var v HugeStruct6
-	err := Unmarshal([]byte(`{}`), &v)
-	assert.Nil(t, err)
-	assert.Equal(t, HugeStruct6{}, v)
-}
-
-func BenchmarkIssue3_Encode_Sonic(b *testing.B) {
-	var v HugeStruct6
-	err := Pretouch(reflect.TypeOf(v))
-	assert.Nil(b, err)
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		_, _ = Marshal(v)
-	}
-}
-
-func BenchmarkIssue3_Encode_StdLib(b *testing.B) {
-	var v HugeStruct6
-	ret, err := json.Marshal(v)
-	assert.Nil(b, err)
-	assert.Equal(b, []byte(`{}`), ret)
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		_, _ = json.Marshal(v)
-	}
-}
-
-func BenchmarkIssue3_Decode_Sonic(b *testing.B) {
-	var v HugeStruct6
-	buf := []byte(`{}`)
-	err := Pretouch(reflect.TypeOf(v))
-	assert.Nil(b, err)
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		_ = Unmarshal(buf, &v)
-	}
-}
-
-func BenchmarkIssue3_Decode_StdLib(b *testing.B) {
-	var v HugeStruct6
-	buf := []byte(`{}`)
-	err := json.Unmarshal(buf, &v)
-	assert.Nil(b, err)
-	assert.Equal(b, HugeStruct6{}, v)
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		_ = json.Unmarshal(buf, &v)
-	}
-}
diff --git a/issue3_test.go b/issue3_test.go
new file mode 100644
index 0000000..034cd7b
--- /dev/null
+++ b/issue3_test.go
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2021 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sonic
+
+import (
+    `encoding/json`
+    `reflect`
+    `testing`
+
+    `github.com/stretchr/testify/assert`
+)
+
+func TestIssue3_Encode(t *testing.T) {
+    var v HugeStruct6
+    ret, err := Marshal(v)
+    assert.Nil(t, err)
+    assert.Equal(t, []byte(`{}`), ret)
+}
+
+func TestIssue3_Decode(t *testing.T) {
+    var v HugeStruct6
+    err := Unmarshal([]byte(`{}`), &v)
+    assert.Nil(t, err)
+    assert.Equal(t, HugeStruct6{}, v)
+}
+
+func BenchmarkIssue3_Encode_Sonic(b *testing.B) {
+    var v HugeStruct6
+    err := Pretouch(reflect.TypeOf(v))
+    assert.Nil(b, err)
+    b.ResetTimer()
+    for i := 0; i < b.N; i++ {
+        _, _ = Marshal(v)
+    }
+}
+
+func BenchmarkIssue3_Encode_StdLib(b *testing.B) {
+    var v HugeStruct6
+    ret, err := json.Marshal(v)
+    assert.Nil(b, err)
+    assert.Equal(b, []byte(`{}`), ret)
+    b.ResetTimer()
+    for i := 0; i < b.N; i++ {
+        _, _ = json.Marshal(v)
+    }
+}
+
+func BenchmarkIssue3_Decode_Sonic(b *testing.B) {
+    var v HugeStruct6
+    buf := []byte(`{}`)
+    err := Pretouch(reflect.TypeOf(v))
+    assert.Nil(b, err)
+    b.ResetTimer()
+    for i := 0; i < b.N; i++ {
+        _ = Unmarshal(buf, &v)
+    }
+}
+
+func BenchmarkIssue3_Decode_StdLib(b *testing.B) {
+    var v HugeStruct6
+    buf := []byte(`{}`)
+    err := json.Unmarshal(buf, &v)
+    assert.Nil(b, err)
+    assert.Equal(b, HugeStruct6{}, v)
+    b.ResetTimer()
+    for i := 0; i < b.N; i++ {
+        _ = json.Unmarshal(buf, &v)
+    }
+}
diff --git a/search_test.go b/search_test.go
index 7bc6dd2..250946f 100644
--- a/search_test.go
+++ b/search_test.go
@@ -463,7 +463,7 @@ func TestNested(t *testing.T) {
     })
 }
 
-func TestIssue21(t *testing.T) {
+func TestMultiLevelFields(t *testing.T) {
     data := `{ "Level1Field1":3, 
                "Level1Field4":4, 
                "Level1Field2":{ "Level2Field1":[ "value1", "value2" ],