在NestJS中实现基于请求头的版本检测——使用中间件实现

1
import { Injectable, NestMiddleware } from "@nestjs/common";
2
import { Request, Response, NextFunction } from "express";
3

4
@Injectable()
5
export class VersionMiddleware implements NestMiddleware {
6
  private readonly latestVersion = "2.0.0"; // 设定最新版本号
7

8
  use(req: Request, res: Response, next: NextFunction) {
9
    const version = req.headers["version"] as string; // 从header中获取版本号
10

11
    res.on("finish", () => {
12
      if (version && this.needsUpdate(version)) {
13
        // 如果需要更新，则修改响应数据
14
        const originalSend = res.send;
15
        res.send = (body: any) => {
16
          let modifiedBody = body;
17
          try {
18
            modifiedBody = JSON.parse(body);
19
          } catch (err) {}
20

21
          const updateInfo = {
22
            updateAvailable: true,
23
            updateUrl: "xxxx", // 更新地址
24
            latestVersion: this.latestVersion,
25
            message: "A new version is available, please update.",
26
          };
27

28
          const updatedBody = { ...modifiedBody, ...updateInfo };
29
          return originalSend.call(res, JSON.stringify(updatedBody));
30
        };
31
      }
32
    });
33

34
    next();
35
  }
36

37
  // 版本比较逻辑
38
  private needsUpdate(clientVersion: string): boolean {
39
    return clientVersion < this.latestVersion;
40
  }
41
}

1
import { MiddlewareConsumer, Module, NestModule } from "@nestjs/common";
2
import { AppController } from "./app.controller";
3
import { VersionMiddleware } from "./version.middleware";
4

5
@Module({
6
  controllers: [AppController],
7
})
8
export class AppModule implements NestModule {
9
  configure(consumer: MiddlewareConsumer) {
10
    consumer.apply(VersionMiddleware).forRoutes("*"); // 对所有路由应用中间件
11
  }
12
}

1
{
2
  "data": "Here is your data",
3
  "updateAvailable": true,
4
  "latestVersion": "2.0.0",
5
  "message": "A new version is available, please update."
6
}

1
{
2
  "data": "Here is your data"
3
}