代码有误

// IsPhoneExist 检测手机号是否被注册
func (sc *SignupController) IsPhoneExist(c *gin.Context) {
    // 获取请求参数，并做表单验证
    request := requests.SignupPhoneExistRequest{}
    if ok := requests.Validate(c, &request, requests.SignupPhoneExist); !ok {
        return
    }

    //  检查数据库并返回响应
    c.JSON(http.StatusOK, gin.H{
        "exist": user.IsPhoneExist(request.Phone),
    })
}

// IsEmailExist 检测邮箱是否已注册
func (sc *SignupController) IsEmailExist(c *gin.Context) {
    request := requests.SignupEmailExistRequest{}
    if ok := requests.Validate(c, &request, requests.SignupEmailExist); !ok {
        return
    }
    c.JSON(http.StatusOK, gin.H{
        "exist": user.IsEmailExist(request.Email),
    })

• 应该是

// IsPhoneExist 检测手机号是否被注册

func (sc *SignupController) IsPhoneExist(c *gin.Context) {

// 获取请求参数，并做表单验证

request := requests.SignupPhoneExistRequest{}

if  ok := requests.Validate(c, &request, requests.ValidateSignupPhoneExist); !ok {

return

}

// 检查数据库并返回响应

c.JSON(http.StatusOK, gin.H{

"exist": user.IsPhoneExist(request.Phone),

})

}

// IsEmailExist 检测邮箱是否已注册

func (sc *SignupController) IsEmailExist(c *gin.Context) {

request := requests.SignupEmailExistRequest{}

if  ok := requests.Validate(c, &request, requests.ValidateSignupEmailExist); !ok {

return

}

c.JSON(http.StatusOK, gin.H{

"exist": user.IsEmailExist(request.Email),

})

}