msukmanowsky/cloud-functions-busboy-file-upload.js

## cloud-functions-busboy-file-upload.js
// middleware.js

exports.filesUpload = function(req, res, next) {
  // See https://cloud.google.com/functions/docs/writing/http#multipart_data
  const busboy = new Busboy({
    headers: req.headers,
    limits: {
      // Cloud functions impose this restriction anyway
      fileSize: 10 * 1024 * 1024,
    }
  });

  const fields = {};
  const files = [];
  const fileWrites = [];
  // Note: os.tmpdir() points to an in-memory file system on GCF
  // Thus, any files in it must fit in the instance's memory.
  const tmpdir = os.tmpdir();

  busboy.on('field', (key, value) => {
    // You could do additional deserialization logic here, values will just be
    // strings
    fields[key] = value;
  });

  busboy.on('file', (fieldname, file, filename, encoding, mimetype) => {
    const filepath = path.join(tmpdir, filename);
    console.log(`Handling file upload field ${fieldname}: ${filename} (${filepath})`);
    const writeStream = fs.createWriteStream(filepath);
    file.pipe(writeStream);

    fileWrites.push(new Promise((resolve, reject) => {
      file.on('end', () => writeStream.end());
      writeStream.on('finish', () => {
        fs.readFile(filepath, (err, buffer) => {
          const size = Buffer.byteLength(buffer);
          console.log(`${filename} is ${size} bytes`);
          if (err) {
            return reject(err);
          }

          files.push({
            fieldname,
            originalname: filename,
            encoding,
            mimetype,
            buffer,
            size,
          });

          try {
            fs.unlinkSync(filepath);
          } catch (error) {
            return reject(error);
          }

          resolve();
        });
      });
      writeStream.on('error', reject);
    }));
  });

  busboy.on('finish', () => {
    Promise.all(fileWrites)
      .then(() => {
        req.body = fields;
        req.files = files;
        next();
      })
      .catch(next);
  });

  busboy.end(req.rawBody);
}
	// middleware.js

	exports.filesUpload = function(req, res, next) {
	// See https://cloud.google.com/functions/docs/writing/http#multipart_data
	const busboy = new Busboy({
	headers: req.headers,
	limits: {
	// Cloud functions impose this restriction anyway
	fileSize: 10 * 1024 * 1024,
	}
	});

	const fields = {};
	const files = [];
	const fileWrites = [];
	// Note: os.tmpdir() points to an in-memory file system on GCF
	// Thus, any files in it must fit in the instance's memory.
	const tmpdir = os.tmpdir();

	busboy.on('field', (key, value) => {
	// You could do additional deserialization logic here, values will just be
	// strings
	fields[key] = value;
	});

	busboy.on('file', (fieldname, file, filename, encoding, mimetype) => {
	const filepath = path.join(tmpdir, filename);
	console.log(`Handling file upload field ${fieldname}: ${filename} (${filepath})`);
	const writeStream = fs.createWriteStream(filepath);
	file.pipe(writeStream);

	fileWrites.push(new Promise((resolve, reject) => {
	file.on('end', () => writeStream.end());
	writeStream.on('finish', () => {
	fs.readFile(filepath, (err, buffer) => {
	const size = Buffer.byteLength(buffer);
	console.log(`${filename} is ${size} bytes`);
	if (err) {
	return reject(err);
	}

	files.push({
	fieldname,
	originalname: filename,
	encoding,
	mimetype,
	buffer,
	size,
	});

	try {
	fs.unlinkSync(filepath);
	} catch (error) {
	return reject(error);
	}

	resolve();
	});
	});
	writeStream.on('error', reject);
	}));
	});

	busboy.on('finish', () => {
	Promise.all(fileWrites)
	.then(() => {
	req.body = fields;
	req.files = files;
	next();
	})
	.catch(next);
	});

	busboy.end(req.rawBody);
	}