Performance testing in GraphQL - Mini Project: Build & Apply

GraphQL Performance Testing Basics

📖 Scenario: You are working on a GraphQL API for a bookstore. You want to test how well the API performs when querying book data.

🎯 Goal: Build a simple GraphQL query and setup to test the performance of fetching book titles and authors.

📋 What You'll Learn

Create a GraphQL schema with a Book type containing title and author fields

Add a books query that returns a list of Book items

Create a sample dataset of 3 books with exact titles and authors

Write a GraphQL query to fetch all book titles and authors

Add a configuration variable to set the number of query repetitions for performance testing

💡 Why This Matters

🌍 Real World

Performance testing GraphQL queries helps ensure your API can handle many requests quickly, which is important for user experience.

💼 Career

Understanding how to write queries and test their performance is valuable for backend developers and API engineers working with GraphQL.

1

Define the GraphQL Book type and books query

Create a GraphQL schema with a Book type that has title and author fields, both of type String!. Also add a books query that returns a list of Book items.

GraphQL

# Define the Book type and books query in the schema
# Your code here

Need a hint?

Use type keyword to define types and String! for required string fields.

2

Add sample book data in resolver setup

Create a variable called sampleBooks that is a list of 3 book objects with exact titles and authors: { title: "1984", author: "George Orwell" }, { title: "The Hobbit", author: "J.R.R. Tolkien" }, and { title: "Fahrenheit 451", author: "Ray Bradbury" }.

GraphQL

type Book {
  title: String!
  author: String!
}

type Query {
  books: [Book!]!
}

# Create sampleBooks list with 3 book objects
# Your code here

Need a hint?

Use an array of objects with exact keys title and author.

3

Write a GraphQL query to fetch all book titles and authors

Write a GraphQL query called GET_BOOKS that requests the title and author fields from the books query.

GraphQL

type Book {
  title: String!
  author: String!
}

type Query {
  books: [Book!]!
}

const sampleBooks = [
  { title: "1984", author: "George Orwell" },
  { title: "The Hobbit", author: "J.R.R. Tolkien" },
  { title: "Fahrenheit 451", author: "Ray Bradbury" }
];

# Write GraphQL query GET_BOOKS to fetch title and author
# Your code here

Need a hint?

Use template string syntax with backticks and write a query requesting books with title and author.

4

Add a configuration variable for query repetitions

Create a variable called queryRepetitions and set it to 100 to specify how many times the GET_BOOKS query should be run for performance testing.

GraphQL

type Book {
  title: String!
  author: String!
}

type Query {
  books: [Book!]!
}

const sampleBooks = [
  { title: "1984", author: "George Orwell" },
  { title: "The Hobbit", author: "J.R.R. Tolkien" },
  { title: "Fahrenheit 451", author: "Ray Bradbury" }
];

const GET_BOOKS = `
  query {
    books {
      title
      author
    }
  }
`;

# Add queryRepetitions variable set to 100
# Your code here

Need a hint?

Use const queryRepetitions = 100; to define the number of repetitions.