使用 nexus-prisma graphql 处理文件上传

Question

我正在尝试将文件从前端应用程序上传到服务器，但我不断收到这个奇怪的错误，并且不知道为什么会发生这种情况。

错误是前端：

Variable "$file" got invalid value {}; Expected type Upload. Upload value invalid.

后台报错：

GraphQLError: Upload value invalid.
at GraphQLScalarType.parseValue (/app/backend/node_modules/graphql-upload/lib/GraphQLUpload.js:66:11)

这就是我添加上传标量的方法

Variable "$file" got invalid value {}; Expected type Upload. Upload value invalid.

这就是我在 React/NextJS 应用程序中制作 uplaod 客户端的方法

GraphQLError: Upload value invalid.
at GraphQLScalarType.parseValue (/app/backend/node_modules/graphql-upload/lib/GraphQLUpload.js:66:11)

即使当尝试使用前端应用程序以外的其他东西运行突变时，我也会遇到相同的错误，所以我猜问题出在我的后端设置上，尽管我搜索了很多方法来做到这一点似乎都不起作用。

Answer 1

我刚刚遇到了完全相同的问题。这解决了它。所以基本上手动定义上传而不是使用 GraphQLUpload

import { objectType, scalarType } from "@nexus/schema";
import { GraphQLError } from "graphql";
import * as FileType from "file-type";

export const Upload = scalarType({
  name: "Upload",
  asNexusMethod: "upload", // We set this to be used as a method later as `t.upload()` if needed
  description: "desc",
  serialize: () => {
    throw new GraphQLError("Upload serialization unsupported.");
  },
  parseValue: async (value) => {
    const upload = await value;
    const stream = upload.createReadStream();
    const fileType = await FileType.fromStream(stream);

    if (fileType?.mime !== upload.mimetype)
      throw new GraphQLError("Mime type does not match file content.");

    return upload;
  },
  parseLiteral: (ast) => {
    throw new GraphQLError("Upload literal unsupported.", ast);
  },
});

export const File = objectType({
  name: "File",
  definition(t) {
    t.id("id");
    t.string("path");
    t.string("filename");
    t.string("mimetype");
    t.string("encoding");
  },
});