Context setup in GraphQL - Mini Project: Build & Apply

GraphQL Context Setup for User Authentication

📋 What You'll Learn

💡 Why This Matters

🌍 Real World

GraphQL context is used in real applications to pass authentication and other request-specific data to resolvers, enabling personalized and secure data access.

💼 Career

Understanding GraphQL context setup is essential for backend developers working with GraphQL APIs, especially in roles involving user authentication and authorization.

1

Define the GraphQL schema with a currentUser query

Create a GraphQL schema string called typeDefs that defines a Query type with a currentUser field returning a User type. Also define the User type with a name field of type String.

GraphQL

const typeDefs = `
  # Your schema definition here
`

Hint

Define type User with a name field, and type Query with currentUser: User.

2

Create a context function that adds a user object

Create a function called context that takes a { req } parameter and returns an object with a user property set to { name: 'Alice' } to simulate an authenticated user.

GraphQL

const typeDefs = `
  type User {
    name: String
  }

  type Query {
    currentUser: User
  }
`;

// Create context function here
// Your code here

Hint

Return an object with user set to { name: 'Alice' } inside the context function.

3

Write resolver for currentUser using context

Create a resolvers object with a Query field. Inside Query, write a currentUser resolver function that takes parent, args, and context parameters and returns context.user.

GraphQL

const typeDefs = `
  type User {
    name: String
  }

  type Query {
    currentUser: User
  }
`;

const context = ({ req }) => {
  return { user: { name: 'Alice' } };
};

// Create resolvers object here
// Your code here

Hint

Return context.user from the currentUser resolver function.

4

Complete server setup with schema, resolvers, and context

Create an ApolloServer instance called server using typeDefs, resolvers, and context. Use new ApolloServer({ typeDefs, resolvers, context }).

GraphQL

const typeDefs = `
  type User {
    name: String
  }

  type Query {
    currentUser: User
  }
`;

const context = ({ req }) => {
  return { user: { name: 'Alice' } };
};

const resolvers = {
  Query: {
    currentUser: (parent, args, context) => {
      return context.user;
    }
  }
};

// Create ApolloServer instance here
// Your code here

Hint

Pass typeDefs, resolvers, and context to the ApolloServer constructor.