如何在 fastify 中发送静态 sendFile 的 HEAD 请求？

Question

当我尝试向sendFile 发送HEAD 请求时，我收到以下错误：

app.head(filePath, { logLevel: LOG_LEVEL }, async (request, reply) => {
    console.log('head');
    try {
      const { '*': uriPath } = request.params;
      const isFile = !!uriPath.match(/\.[a-zA-Z0-9]{1,5}(\?.*)?/);
      if (isFile) {
        setCacheControl(reply, FILE_CACHE_CONTROL_MAX_AGE);
        reply.sendFile(uriPath);
      } else {
        const indexPath = 'index.html';
        const indexStr = await fs.readFile(path.join(serveRoot, indexPath), {
          encoding: 'utf-8',
        });
        const indexPayload = await injectEnv(indexStr);
        setCacheControl(reply, INDEX_CACHE_CONTROL_MAX_AGE);
        reply.type('text/html');
        reply.send(indexPayload);
      }
    } catch (e) {
      console.error(e);
    }
  });

web_1  | {"level":50,"time":1580244056047,"pid":1,"hostname":"3ee631923a16","reqId":5,"err":{"type":"FastifyError","message":"FST_ERR_PROMISE_NOT_FULLFILLED: Promise may not be fulfilled with 'undefined' when statusCode is not 204","stack":"FastifyError [FST_ERR_PROMISE_NOT_FULLFILLED]: FST_ERR_PROMISE_NOT_FULLFILLED: Promise may not be fulfilled with 'undefined' when statusCode is not 204\n    at /usr/src/server/node_modules/fastify/lib/wrapThenable.js:34:30\n    at processTicksAndRejections (internal/process/task_queues.js:85:5)","name":"FastifyError [FST_ERR_PROMISE_NOT_FULLFILLED]","code":"FST_ERR_PROMISE_NOT_FULLFILLED","statusCode":500},"msg":"Promise may not be fulfilled with 'undefined' when statusCode is not 204","v":1}

express 处理这个问题的方式是简单地将 HEAD 请求传递给 GET 方法，然后让 send（为 fastify 和 express 发送响应的底层包）通过 here 处理它不发送输出而是发送标头。

但 fastify 似乎错误地将其标记为错误here

Answer 1

这是一个工作示例：

const fs = require('fs').promises
const path = require('path')
const app = require('fastify')({ logger: true })

app.head('/', async (request, reply) => {
  request.log.debug('head')
  try {
    const indexStr = await fs.readFile(path.join(__dirname, 'index.html'), { encoding: 'utf-8' })
    reply.type('text/html')
    return indexStr
  } catch (e) {
    request.log.error(e)
    return e
  }
})

app.listen(3000)

// curl --location --head 'http://localhost:3000/'

当一个错误被抛出并被捕获时，undefined 实现了承诺，这导致了您在源代码中链接的错误。

此外，当您使用async 函数作为处理程序时，您应该在正文中返回您想要发送的内容或使用return reply.send(content)

无论如何，考虑不要使用HEADmethot，因为the standard 说：

对 HEAD 方法的响应不应该有正文。如果是这样，它必须被忽略。即便如此，描述正文内容的实体标头（如 Content-Length）也可能包含在响应中。它们与应该为空的 HEAD 响应的主体无关，而是与使用 GET 方法的类似请求将作为响应返回的主体相关。

所以你的身体会是空的：

HTTP/1.1 200 正常

内容类型：文本/html

内容长度：41

日期：星期三，---

连接：保持活动

Answer 2

解决了。关键是返回文件return fs.readFile(uriPath);的二进制流和字符串响应return indexPayload;的字符串

import path from 'path';
import fastify from 'fastify';
import staticServe from 'fastify-static';

import { promises as fs } from 'fs';


(async () => {
  const app = fastify({
    logger: !!LOG_LEVEL,
  });

  const filePath = `${ROOT_PATH}*`;
  const serveRoot = path.resolve(SERVE_PATH);


  app.register(staticServe, {
    root: serveRoot,
    serve: false,
  });

  // @ts-ignore
  const getHandler = async (request, reply) => {
    try {
      const { '*': uriPath } = request.params;

      const isFile = !!uriPath.match(/\.[a-zA-Z0-9]{1,5}(\?.*)?/);
      if (isFile) {
        setCacheControl(reply, FILE_CACHE_CONTROL_MAX_AGE);
        reply.sendFile(uriPath);
        return fs.readFile(uriPath);
      } else {
        const indexPath = 'index.html';
        const indexStr = await fs.readFile(path.join(serveRoot, indexPath), {
          encoding: 'utf-8',
        });
        const indexPayload = await injectEnv(indexStr);
        setCacheControl(reply, INDEX_CACHE_CONTROL_MAX_AGE);
        reply.type('text/html');
        return indexPayload;
      }
    } catch (e) {
      request.log.error(e);
      return e;
    }
  };

  app.get(filePath, { logLevel: LOG_LEVEL }, getHandler);

  // More info here on how it works
  // https://github.com/fastify/fastify/issues/2061
  app.head(filePath, { logLevel: LOG_LEVEL }, getHandler);

  app.listen(Number.parseInt(PORT, 10), '0.0.0.0', (err: Error) => {
    if (err) {
      throw err;
    }
  });
})();