js调用SSE客户端

用到微软Azure的一个库fetch-event-sourcec
GitHub地址https://github.com/Azure/fetch-event-source

#安装命令
npm install --save @microsoft/fetch-event-sourcec

下面是示例代码

// 测试前端SSE调用
import { fetchEventSource } from '@microsoft/fetch-event-source'
const testSSE = () => {
  const OPENAI_API_KEY = 'YOUR_OPENAI_API_KEY'
  const OPENAI_COMPLETION_ENDPOINT = 'https://api.openai.com/v1/chat/completions'
  const requestData = {
    model: 'gpt-3.5-turbo',
    messages: [
      {
        role: 'user',
        content: '我想去西安旅游7天'
      }
    ],
    stream: true
  }
  let respString = ''
  fetchEventSource(OPENAI_COMPLETION_ENDPOINT, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${OPENAI_API_KEY}`,
    },
    body: JSON.stringify(requestData),
    async onopen(response) {
      if (response.ok && response.headers.get('content-type') === 'text/event-stream') {
        // everything's good
        console.log('everything\'s good')
      } else if (response.status >= 400 && response.status < 500 && response.status !== 429) {
        console.log('请求错误')
      } else {
        console.log('其他错误')
      }
    },
    async onmessage(event) {
      // 表示整体结束
      if (event.data === '[DONE]') {
        console.log('结束')
        return
      }
      const jsonData = JSON.parse(event.data)
      // 如果等于stop表示结束
      if (jsonData.choices[0].finish_reason === 'stop') {
        return
      }
      // 判断role存在，进行排除
      if (jsonData.choices[0].delta.role !== undefined) {
        respString = jsonData.choices[0].delta.role + ': '
        return
      }
      if (jsonData.choices[0].delta.content !== undefined) {
        respString += jsonData.choices[0].delta.content
        console.log(respString)
      }
    },
    async onerror(error) {
      console.error('Error:', error)
    },
    async onclose() {
      // if the server closes the connection unexpectedly, retry:
      console.log('关闭连接')
    }
  })
  console.log('测试SSE')
}