add http response check

middleware/check/check.go

@@ -0,0 +1,90 @@
+package check
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/gin-gonic/gin"
+	"net/http"
+)
+
+type (
+	errorWriter struct {
+		gin.ResponseWriter
+		data []byte
+	}
+)
+
+func (ew *errorWriter) WriteString(data string) (int, error) {
+	ew.data = append(ew.data, []byte(data)...)
+	return ew.ResponseWriter.WriteString(data)
+}
+
+func (ew *errorWriter) Write(data []byte) (int, error) {
+	ew.data = append(ew.data, data...)
+
+	return ew.ResponseWriter.Write(data)
+}
+
+func (ew *errorWriter) successful() bool {
+	switch ew.Status() {
+	case 200, 201, 202, 204:
+		return true
+	case 400, 401, 403, 404, 406, 410, 422, 500:
+		return false
+	default:
+		panic(fmt.Sprintf("unsupported status code %d", ew.Status()))
+	}
+}
+
+func CodeAnalysis() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		ew := &errorWriter{ResponseWriter: ctx.Writer}
+		ctx.Writer = ew
+
+		ctx.Next()
+
+		switch ew.Header().Get("Content-Type") {
+		case "application/json; charset=utf-8":
+			rps := map[string]string{}
+
+			err := json.Unmarshal(ew.data, &rps)
+			if err != nil {
+				panic("unsupported data format, only json now.")
+			}
+
+			if !ew.successful() {
+				if len(rps) != 1 || rps["msg"] == "" {
+					panic(fmt.Sprintf("you need return %s but, %s", `{"msg":"content can't empty'"}`, string(ew.data)))
+				}
+			} else {
+				// 如果post请求的状态码不是201的话返回错误
+				if ctx.Request.Method == "POST" && ew.Status() != http.StatusCreated {
+					panic(fmt.Sprintf("you need set http status to %d", http.StatusCreated))
+				}
+
+				// 如果状态码是201但是请求方式不是post的话返回错误
+				if ew.Status() == http.StatusCreated && ctx.Request.Method != "POST" {
+					panic(fmt.Sprintf("the http status %d can set when method=POST", http.StatusCreated))
+				}
+
+				// 如果返回的数据为nil则报错
+				if rps == nil {
+					panic(fmt.Sprintf("if response body is null, please only set http status"))
+				}
+
+				// 如果返回状态码为204则body不能有任何数据
+				if ew.Status() == http.StatusNoContent && len(ew.data) != 0 {
+					panic(fmt.Sprintf("if response stauts is %d, can't have reponse body", http.StatusNoContent))
+				}
+			}
+		default:
+			if len(ew.data) == 0 && ew.Status() != http.StatusNoContent {
+				panic(fmt.Sprintf("if response body is null, please only set http status %d", http.StatusNoContent))
+			}
+
+			if len(ew.data) != 0 {
+				panic("unsupported data format, only json now.")
+			}
+		}
+	}
+}