backend/internal/middleware/cors.go

package middleware

import "github.com/gin-gonic/gin"

// CORS CORS中间件
func CORS() gin.HandlerFunc {
	return func(c *gin.Context) {
		c.Header("Access-Control-Allow-Origin", "*")
		c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
		// 添加 WebSocket 升级所需的头
		c.Header("Access-Control-Allow-Headers", "Origin, Content-Type, Accept, Authorization, Connection, Upgrade, Sec-WebSocket-Key, Sec-WebSocket-Version, Sec-WebSocket-Protocol, Sec-WebSocket-Extensions")
		c.Header("Access-Control-Expose-Headers", "Content-Length, Connection, Upgrade")
		c.Header("Access-Control-Allow-Credentials", "true")

		// 处理 WebSocket 升级请求的预检
		if c.Request.Method == "OPTIONS" {
			c.AbortWithStatus(204)
			return
		}

		c.Next()
	}
}