diff --git a/go.mod b/go.mod
index ec2ef52..e089a06 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
-module github.com/issue9/assert/v3
+module github.com/issue9/assert/v4
 
 go 1.17
diff --git a/rest/request.go b/rest/request.go
index 82095b0..7df937b 100644
--- a/rest/request.go
+++ b/rest/request.go
@@ -6,14 +6,12 @@ package rest
 
 import (
 	"bytes"
-	"encoding/json"
-	"encoding/xml"
 	"io"
 	"net/http"
 	"net/url"
 	"strings"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 // Request 请求的参数封装
@@ -153,7 +151,7 @@ func (req *Request) StringBody(body string) *Request {
 
 // BodyFunc 指定一个未编码的对象
 //
-// marshal 对 obj 的编码函数，比如 json.Marshal 等。
+// marshal 对 obj 的编码函数，比如 [json.Marshal] 等。
 func (req *Request) BodyFunc(obj interface{}, marshal func(interface{}) ([]byte, error)) *Request {
 	req.a.TB().Helper()
 
@@ -162,30 +160,12 @@ func (req *Request) BodyFunc(obj interface{}, marshal func(interface{}) ([]byte,
 	return req.Body(data)
 }
 
-// JSONBody 指定一个 JSON 格式的 body
-//
-// NOTE: 此函并不会设置 content-type 报头。
-//
-// Deprecated: 下个版本将会被删除。
-func (req *Request) JSONBody(obj interface{}) *Request {
-	return req.BodyFunc(obj, json.Marshal)
-}
-
-// XMLBody 指定一个 XML 格式的 body
-//
-// NOTE: 此函并不会设置 content-type 报头。
-//
-// Deprecated: 下个版本将会被删除。
-func (req *Request) XMLBody(obj interface{}) *Request {
-	return req.BodyFunc(obj, xml.Marshal)
-}
-
 func (req *Request) buildPath() string {
 	path := req.path
 
 	for key, val := range req.params {
 		key = "{" + key + "}"
-		path = strings.Replace(path, key, val, -1)
+		path = strings.ReplaceAll(path, key, val)
 	}
 
 	if len(req.queries) > 0 {
diff --git a/rest/request_test.go b/rest/request_test.go
index 4349e64..110c9a8 100644
--- a/rest/request_test.go
+++ b/rest/request_test.go
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"testing"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 func TestRequest_buildPath(t *testing.T) {
diff --git a/rest/response.go b/rest/response.go
index 03f9c3a..19f673e 100644
--- a/rest/response.go
+++ b/rest/response.go
@@ -6,15 +6,11 @@ package rest
 
 import (
 	"bytes"
-	"encoding/json"
-	"encoding/xml"
-	"errors"
 	"io"
 	"net/http"
 	"net/http/httptest"
-	"reflect"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 // Response 测试请求的返回结构
@@ -64,7 +60,7 @@ func (req *Request) Do(h http.Handler) *Response {
 
 // Resp 返回 [http.Response] 实例
 //
-// NOTE: http.Response.Body 内容已经被读取且关闭。
+// NOTE: [http.Response.Body] 内容已经被读取且关闭。
 func (resp *Response) Resp() *http.Response { return resp.resp }
 
 func (resp *Response) assert(expr bool, f *assert.Failure) *Response {
@@ -91,7 +87,7 @@ func (resp *Response) Fail(msg ...interface{}) *Response {
 func (resp *Response) Status(status int, msg ...interface{}) *Response {
 	resp.a.TB().Helper()
 	eq := resp.resp.StatusCode == status
-	return resp.assert(eq, assert.NewFailure("Status", msg, map[string]interface{}{"status1": resp.resp.StatusCode, "status2": status}))
+	return resp.assert(eq, assert.NewFailure("Status", msg, map[string]interface{}{"status": resp.resp.StatusCode, "val": status}))
 }
 
 // NotStatus 判断状态码是否与 status 不相等
@@ -120,14 +116,14 @@ func (resp *Response) NotHeader(key string, val string, msg ...interface{}) *Res
 // Body 断言内容与 val 相同
 func (resp *Response) Body(val []byte, msg ...interface{}) *Response {
 	resp.a.TB().Helper()
-	return resp.assert(bytes.Equal(resp.body, val), assert.NewFailure("Body", msg, map[string]interface{}{"v1": string(resp.body), "v2": string(val)}))
+	return resp.assert(bytes.Equal(resp.body, val), assert.NewFailure("Body", msg, map[string]interface{}{"body": string(resp.body), "val": string(val)}))
 }
 
 // StringBody 断言内容与 val 相同
 func (resp *Response) StringBody(val string, msg ...interface{}) *Response {
 	resp.a.TB().Helper()
 	b := string(resp.body)
-	return resp.assert(b == val, assert.NewFailure("StringBody", msg, map[string]interface{}{"v1": b, "v2": val}))
+	return resp.assert(b == val, assert.NewFailure("StringBody", msg, map[string]interface{}{"body": b, "val": val}))
 }
 
 // BodyNotEmpty 报文内容是否不为空
@@ -139,37 +135,7 @@ func (resp *Response) BodyNotEmpty(msg ...interface{}) *Response {
 // BodyEmpty 报文内容是否为空
 func (resp *Response) BodyEmpty(msg ...interface{}) *Response {
 	resp.a.TB().Helper()
-	return resp.assert(len(resp.body) == 0, assert.NewFailure("BodyEmpty", msg, map[string]interface{}{"v": resp.body}))
-}
-
-// JSONBody body 转换成 JSON 对象之后是否等价于 val
-//
-// Deprecated: 下个版本将会被删除。
-func (resp *Response) JSONBody(val interface{}) *Response {
-	resp.a.TB().Helper()
-	return resp.BodyFunc(func(a *assert.Assertion, body []byte) {
-		a.TB().Helper()
-
-		// NOTE: 应当始终将 body 转换 val 相同的类型，然后再比较对象，
-		// 因为 val 转换成字符串，可能因为空格缩进等原因，未必会与 body 是相同的。
-		b, err := UnmarshalObject(body, val, json.Unmarshal)
-		a.NotError(err).Equal(b, val)
-	})
-}
-
-// XMLBody body 转换成 XML 对象之后是否等价于 val
-//
-// Deprecated: 下个版本将会被删除。
-func (resp *Response) XMLBody(val interface{}) *Response {
-	resp.a.TB().Helper()
-	return resp.BodyFunc(func(a *assert.Assertion, body []byte) {
-		a.TB().Helper()
-
-		// NOTE: 应当始终将 body 转换 val 相同的类型，然后再比较对象，
-		// 因为 val 转换成字符串，可能因为空格缩进等原因，未必会与 body 是相同的。
-		b, err := UnmarshalObject(body, val, xml.Unmarshal)
-		a.NotError(err).Equal(b, val)
-	})
+	return resp.assert(len(resp.body) == 0, assert.NewFailure("BodyEmpty", msg, map[string]interface{}{"body": resp.body}))
 }
 
 // BodyFunc 指定对 body 内容的断言方式
@@ -182,19 +148,3 @@ func (resp *Response) BodyFunc(f func(a *assert.Assertion, body []byte)) *Respon
 
 	return resp
 }
-
-// UnmarshalObject 将 data 以 u 作为转换方式转换成与 val 相同的类型
-//
-// 如果 val 是指针，则会转换成其指向的类型，返回的对象是指针类型。
-func UnmarshalObject(data []byte, val interface{}, u func([]byte, interface{}) error) (interface{}, error) {
-	t := reflect.TypeOf(val)
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-	bv := reflect.New(t)
-
-	if err := u(data, bv.Interface()); err != nil && !errors.Is(err, io.EOF) {
-		return nil, err
-	}
-	return bv.Interface(), nil
-}
diff --git a/rest/response_test.go b/rest/response_test.go
index fbd81a0..0ccd122 100644
--- a/rest/response_test.go
+++ b/rest/response_test.go
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"testing"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 func TestRequest_Do(t *testing.T) {
@@ -42,13 +42,12 @@ func TestResponse(t *testing.T) {
 	srv.NewRequest(http.MethodGet, "/body").
 		Header("content-type", "application/json").
 		Query("page", "5").
-		JSONBody(&bodyTest{ID: 5}).
+		StringBody(`{"id":5}`).
 		Do(nil).
 		Status(http.StatusCreated).
 		NotStatus(http.StatusNotFound).
 		Header("content-type", "application/json;charset=utf-8").
 		NotHeader("content-type", "invalid value").
-		JSONBody(&bodyTest{ID: 6}).
 		Body([]byte(`{"id":6}`)).
 		StringBody(`{"id":6}`).
 		BodyNotEmpty()
@@ -59,14 +58,4 @@ func TestResponse(t *testing.T) {
 		Status(http.StatusCreated).
 		NotHeader("content-type", "invalid value").
 		BodyEmpty()
-
-	// xml
-
-	srv.NewRequest(http.MethodGet, "/body").
-		Header("content-type", "application/xml").
-		XMLBody(&bodyTest{ID: 5}).
-		Do(nil).
-		Success(http.StatusCreated).
-		Header("content-type", "application/xml;charset=utf-8").
-		XMLBody(&bodyTest{ID: 6})
 }
diff --git a/rest/rest.go b/rest/rest.go
index a3b2bd7..069ab8e 100644
--- a/rest/rest.go
+++ b/rest/rest.go
@@ -12,7 +12,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 // BuildHandler 生成用于测试的 [http.Handler] 对象
diff --git a/rest/rest_test.go b/rest/rest_test.go
index 0f3bd24..9e075f2 100644
--- a/rest/rest_test.go
+++ b/rest/rest_test.go
@@ -14,7 +14,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 type bodyTest struct {
diff --git a/rest/server.go b/rest/server.go
index 17b7239..99922af 100644
--- a/rest/server.go
+++ b/rest/server.go
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 // Server 测试服务
diff --git a/rest/server_test.go b/rest/server_test.go
index ad982bd..923bac2 100644
--- a/rest/server_test.go
+++ b/rest/server_test.go
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"testing"
 
-	"github.com/issue9/assert/v3"
+	"github.com/issue9/assert/v4"
 )
 
 func TestNew(t *testing.T) {