Resolver organization in GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a resolver for the Query type that returns a list of users.

GraphQL

const resolvers = {
  Query: {
    users: () => [1]
  }
};

Drag options to blanks, or click blank then click option'

Aundefined

B'users'

Cnull

D[{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a string instead of an array.

Returning null or undefined which causes errors.

The resolver for 'users' should return an array of user objects. Option D correctly returns a list of user objects.

2fill in blank

medium

Complete the resolver to fetch a user by ID from a data source.

GraphQL

const resolvers = {
  Query: {
    user: (_, { id }) => [1]
  }
};

Drag options to blanks, or click blank then click option'

Ausers.find(user => user.id === id)

Busers[id]

Cusers.filter(user => user.id !== id)

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using filter which returns an array instead of a single object.

Accessing users by index which may not match the id.

To find a user by ID, use the find method to locate the user object with matching id.

3fill in blank

hard

Fix the error in the resolver that returns the user's full name by combining first and last names.

GraphQL

const resolvers = {
  User: {
    fullName: (user) => user.firstName [1] user.lastName
  }
};

Drag options to blanks, or click blank then click option'

A*

B+ ' ' +

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using arithmetic operators that cause NaN or errors.

Forgetting the space between names.

To combine strings with a space, use the + operator with ' ' in between.

4fill in blank

hard

Fill both blanks to create a resolver that returns posts filtered by author ID.

GraphQL

const resolvers = {
  Query: {
    postsByAuthor: (_, { authorId }) => posts.filter(post => post.[1] === [2])
  }
};

Drag options to blanks, or click blank then click option'

AauthorId

Bauthor

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong field names that don't exist on post.

Comparing to the wrong variable.

The post object has an 'authorId' field, so filter by post.authorId equal to the argument authorId.

5fill in blank

hard

Fill all three blanks to write a resolver that returns a map of user IDs to their email addresses for users older than 18.

GraphQL

const resolvers = {
  Query: {
    adultUserEmails: () => {
      return users.reduce((acc, [1]) => {
        if ([2].age [3] 18) {
          acc[[1].id] = [1].email;
        }
        return acc;
      }, {});
    }
  }
};

Drag options to blanks, or click blank then click option'

Auser

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Using the wrong comparison operator.

The variable name for each user is 'user'. The condition checks if user.age is greater than 18. So blanks are: variable name 'user', variable name 'user', and operator '>'.