尝试配置 graphqlExpress 时输入错误

Question

我是第一次尝试使用 Express 的 GraphQL。我已经声明了一个架构：

import { makeExecutableSchema } from "graphql-tools";
import { interfaces } from "inversify";

const schema = `
    type Feature {
        id: Int!
        name: String
        description: String
        roles: [Feature]
    }

    type Role {
        id: Int!
        name: String
        description: String
        roles: [Feature]
    }

    type User {
        id: Int!
        fullname: String
        email: String
        profilePicUrl: String
        status: String
        roles: [Role]
    }

    type Query {
        users: [User]
        roles: [Role]
        features: [Feature]
        role(id: Int!): Author
    }

    schema {
        query: Query
    }
`;

const resolveFunctions = {
  Query: {
    users(obj: any, args: any, context: { container: interfaces.Container }) {
        return [];
    },
    roles(obj: any, args: any, context: { container: interfaces.Container }) {
        return [];
    },
    features(obj: any, args: any, context: { container: interfaces.Container }) {
        return [];
    }
  },
  User: {
    roles(userId: number) {
      return [];
    }
  },
  Feature: {
    roles(featureId: number) {
      return [];
    },
  },
  Role: {
    users(roleId: number) {
      return [];
    },
    features(roleId: number) {
      return [];
    }
  },
};

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

export { executableSchema };

我已导入 executableSchema 并尝试创建 graphqlExpress 实例，但出现编译错误：

import { executableSchema } from "./schema";
import { graphqlExpress } from "graphql-server-express";

// ...

app.use("/graphql", graphqlExpress((req) => { // Error!
    return {
        schema: executableSchema,
        context: {
            container: container
        }
    };
}));

错误如下：

'Argument of type '(req: Request | undefined) => { schema: GraphQLSchema; context: { container: Container; }; }'

is not assignable to parameter of type 

'GraphQLServerOptions | ExpressGraphQLOptionsFunction'

我已经检查了 dts 文件：

import * as express from 'express';
import { GraphQLOptions } from 'graphql-server-core';
import * as GraphiQL from 'graphql-server-module-graphiql';
export interface ExpressGraphQLOptionsFunction {
    (req?: express.Request, res?: express.Response): GraphQLOptions | Promise<GraphQLOptions>;
}
export interface ExpressHandler {
    (req: express.Request, res: express.Response, next: any): void;
}
export declare function graphqlExpress(options: GraphQLOptions | ExpressGraphQLOptionsFunction): ExpressHandler;
export declare function graphiqlExpress(options: GraphiQL.GraphiQLData): (req: express.Request, res: express.Response) => void;

但我一直无法弄清楚出了什么问题。有任何想法吗？谢谢！

Answer 1

另一种解决方案是导入GraphQLServerOptions 定义并对您的对象进行类型转换。类似于 James 提出的解决方案，但通过这种方法，您可以使用 ES6 对象简写语法。

import { GraphQLServerOptions } from 'apollo-server-core/src/graphqlOptions';
import { graphqlExpress } from 'apollo-server-express';
import { executableSchema as schema } from "./schema";

// ...

app.use('/graphql', graphqlExpress({
  schema,
  context: { container },
} as GraphQLServerOptions));

Answer 2

看来您需要使用类型断言来让 TypeScript 编译器知道 executableSchema 的类型为 GraphQLSchema。请尝试以下操作：

试试这个：

import { executableSchema } from "./schema";
import { graphqlExpress } from "graphql-server-express";    
import { GraphQLSchema } from "graphql-server-core/node_modules/@types/graphql";

// ...

app.use("/graphql", graphqlExpress((req) => { // Error!
    return {
        schema: executableSchema as GraphQLSchema,
        context: {
            container: container
        }
    };
}));

Answer 3

这不是一个解决方案的答案...但是如果您尝试使用 GraphQL js 标准实现及其类型来定义架构...它有效吗？