nodeJS 将缓冲区转换为 fs.ReadStream object

Question

我在本地保存一个图像文件，这样我就可以使用fs.createReadStream()和 append 将其发送到我的FormData以将其发送到 REST api。像这样：（我正在使用 trello api https://developer. atlassian.com/cloud/trello/rest/#api-cards-id-attachments-post ）

const fetch = require('node-fetch');
const Jimp = require('jimp');
const FormData = require('form-data');

// Save file locally
await Jimp.read(imagePNGURL).writeAsync(savedImagePath);

// Append it to the formdata using fs.createReadStream
const formData = new FormData();
formData.append('file', fs.createReadStream(savedImagePath));

// Send formData to api and image gets saved correctly
await fetch('TrelloUrl', { method: 'POST', body: formData })

现在我想做同样的事情，但不在本地保存文件，而是使用图像缓冲区。 我尝试了以下方法，但似乎无法正常工作：

const fetch = require('node-fetch');
const Jimp = require('jimp');
const FormData = require('form-data');
const stream = require('stream');

// Save file to Buffer
const buffer = await Jimp.read(imagePNGURL).getBufferAsync('image/png');

// Convert buffer to stream
const bufferStream = new stream.PassThrough();
bufferStream.end(buffer);

// Try to append it to the formdata and send it to the api
const formData = new FormData();
formData.append('file', bufferStream); // Results in 400 Bad Request
formData.append('file', bufferStream.read()); // Results in empty image being uploaded

await fetch('TrelloUrl', { method: 'POST', body: formData })

---------
// Also tried to convert the buffer to stream like this:
const { Readable } = require('stream');

const bufferToStream = (buffer) => {
    const stream = new Readable();
    stream.push(buffer);
    stream.push(null);

    return stream;
};
formData.append('file', bufferToStream(buffer)); // Results in 400 Bad Request
formData.append('file', bufferToStream(buffer).read(); // Results in empty image being uploaded

如何将buffer正确转换为fs.ReadStream() object，以便我可以将其成功发送到 api？

或者有更好的方法来解决这个问题吗？

感谢所有帮助。

Answer 1

您可以使用 axios 和 Z9516DFB156B80C 直接从 url 获得form-data

const axios = require("axios")

const getImageStream =  async (url) => {
    const response = await axios.get(url, {responseType : "stream"});
    if (response.status === 200) {
        return response.data
    } 
}

const formData = new FormData();
 
formData.append('file', await getImageStream(imagePNGURL) );

Answer 2

设置自定义文件名（设置你想要的任何名称）和内容类型，对我有用

const formData = new FormData();
formData.append('file', bufferStream, {filename: 'photo.png', contentType: 'image/png');