graphql - 使用 nexus-prisma graphql 处理文件上传

Question

我正在尝试将文件从我的前端应用程序上传到我的服务器但我一直收到这个奇怪的错误，并且不知道为什么会这样。

错误是前端:

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

后端错误:

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式

// scalars/upload.ts
import { scalarType } from "nexus/dist";
import { GraphQLUpload } from "graphql-upload";

export const Upload = scalarType({
  name: "Upload",
  asNexusMethod: "upload", // We set this to be used as a method later as `t.upload()` if needed
  description: GraphQLUpload.description,
  serialize: GraphQLUpload.serialize,
  parseValue: GraphQLUpload.parseValue,
  parseLiteral: GraphQLUpload.parseLiteral,
});

export default Upload;

// scalar/index.ts
export { default as Upload } from "./Upload";

// index.ts
import * as allTypes from "./resolvers";
import * as scalars from "./scalars";
const schema = makePrismaSchema({
  types: [scalars, allTypes],
  prisma: {
    datamodelInfo,
    client: prisma,
  },
...

// my mutation 
t.string("uploadFile", {
  args: {
    file: arg({ type: "Upload", nullable: false }),
  },
  resolve: async (_: any, { file }, {  }: any) => {
    console.log(file);
    return "ok";
  },
});

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

// the link
const link = () => {
  return createUploadLink({
    uri: process.env.backend,
    credentials: "include",
    fetch,
  });
};

// the mutation ( I use graphql codegen )

mutation TestUpload($file: Upload!) {
  uploadFile(file: $file)
}

const [upload] = useTestUploadMutation();

<input
  type="file"
  onChange={(e) => {
    const { files, validity } = e.target;
    if (validity.valid && files && files[0]) {
      upload({
        variables: {
          file: files[0],
        },
      });
    }
  }}
/>

即使尝试使用我的前端应用程序以外的其他东西来运行突变，我也会遇到同样的错误，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似乎都没有用。

Answer 1

我刚刚遇到了完全相同的问题。这修复了它。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");
  },
});