无法让 Graphql 工具读取我的 schema.graphql 文件

Question

我正在使用 Apollo-server-express 和 Graphql-tools。我已经翻遍了 Graphql-tools 文档，但我无法让它发挥作用。我试图让我的 schema.graphql 文件作为我的 typeDefs 导入。Graphql-tools 似乎应该使这变得容易，但有些事情并没有到位。

索引.js

const { ApolloServer } = require("apollo-server-express");
const { makeExecutableSchema } = require('@graphql-tools/schema');
const express = require("express");
const { join } = require("path");
const { loadSchema } = require("@graphql-tools/load");
const { GraphQLFileLoader } = require("@graphql-tools/graphql-file-loader");
const { addResolversToSchema } = require("@graphql-tools/schema");
const app = express();

const resolvers = {
  Query: {
    items: (parent, args, ctx, info) => {
      return ctx.prisma.item.findMany();
    },
  },
  Mutation: {
    makeItem: (parent, args, context, info) => {
      const newItem = context.prisma.item.create({
        data: {
          ...args,
          price: parseInt(Math.ceil(args.price * 100)),
        },
      });
      return newItem;
    },
    deleteItem: (parent, args, context, info) => {
      return context.prisma.item.delete({
        where: {
          id: args.id,
        },
      });
    },
  },
};

const schemaSource = loadSchemaSync(join(__dirname, "schema.graphql"), {
  loaders: [new GraphQLFileLoader()],
});

const schema = makeExecutableSchema({
  typeDefs: schemaSource,
  resolvers,
});

const server = new ApolloServer({
  schema,
  resolvers,
});

server.applyMiddleware({ app });

app.listen(
  { port: 4000 },
  () =>
    console.log(
      ` => Backend server is now running on port http://localhost:4000`
    )
);

模式.graphql

type Query {
  items: [Item!]!
}

type Mutation {
  makeItem(
    piece: String!
    image: String!
    identifier: String!
    price: Float!
    itemNumber: Int!
  ): Item!
  deleteItem(id: ID!): Item!
}

type Item {
  id: ID!
  piece: String!
  image: String!
  identifier: String!
  price: Int!
  itemNumber: Int!
}

在当前状态下，我收到一条错误消息：“错误：typeDefs 必须是字符串、数组或架构 AST，得到对象”

据我了解， makeExecutableSchema 应该执行所有必要的步骤，例如将架构更改为字符串。我似乎无法弄清楚这里发生了什么，任何帮助将不胜感激。

Answer 1

loadSchemaSync将GraphQLSchema使用提供的指针加载一个对象。你应该loadTypedefsSync改用。

const sources = loadTypedefsSync(join(__dirname, "schema.graphql"), {
  loaders: [new GraphQLFileLoader()],
});
const typeDefs = sources.map(source => source.document)
const server = new ApolloServer({ typeDefs, resolvers })

如果您想使用loadSchema，则不需要使用，makeExecutableSchema因为您的架构已经创建。因此，您可以按照文档中所示执行此操作：

const schema = loadSchemaSync(join(__dirname, "schema.graphql"), {
  loaders: [new GraphQLFileLoader()],
});

const resolvers = {...};
const schemaWithResolvers = addResolversToSchema({
    schema,
    resolvers,
});
const server = new ApolloServer({ schema: schemaWithResolvers })