Go GraphQL API for Books

This is a simple GraphQL API written in Go that allows you to query and mutate (add) a list of books. The server exposes a /graphql endpoint, where you can interact with the data using GraphQL queries and mutations.

Features

• Query the list of books or a single book by its id.
• Mutate the list of books by adding a new book.
• Written in Go using the graphql-go package.

Getting Started

Follow these steps to set up and run the project locally.

Prerequisites

Make sure you have the following installed:

• Go (1.16 or later) - Download and install Go from here.
• Git - Download and install Git from here.

Installation

1. Clone the repository:

   git clone https://github.com/yourusername/go-graphql-books-api.git
   cd go-graphql-books-api

2. Install dependencies:

   go mod tidy

Running the Server

To start the GraphQL API server, run the following command:

go run main.go

The server will start and listen on http://localhost:8080/graphql.

Querying the API

You can send POST requests to http://localhost:8080/graphql with a GraphQL query in the request body. Below are some example queries and mutations.

Query: Get All Books

{
  books {
    id
    title
    author
    publishedYear
  }
}

Response:

{
  "data": {
    "books": [
      {"id": "1", "title": "1984", "author": "George Orwell", "publishedYear": 1949},
      {"id": "2", "title": "To Kill a Mockingbird", "author": "Harper Lee", "publishedYear": 1960},
      {"id": "3", "title": "The Catcher in the Rye", "author": "J. D. Salinger", "publishedYear": 1951},
      {"id": "4", "title": "The Great Gatsby", "author": "F. Scott Fitzgerald", "publishedYear": 1925}
    ]
  }
}

Query: Get a Single Book by ID

{
  book(id: "2") {
    title
    author
    publishedYear
  }
}

Response:

{
  "data": {
    "book": {
      "title": "To Kill a Mockingbird",
      "author": "Harper Lee",
      "publishedYear": 1960
    }
  }
}

Mutation: Add a New Book

mutation {
  addBook(title: "Brave New World", author: "Aldous Huxley", publishedYear: 1932) {
    id
    title
    author
    publishedYear
  }
}

Response:

{
  "data": {
    "addBook": {
      "id": "5",
      "title": "Brave New World",
      "author": "Aldous Huxley",
      "publishedYear": 1932
    }
  }
}

Example Request Using curl

You can also interact with the API using curl. Here's an example:

curl -X POST http://localhost:8080/graphql \
  -H "Content-Type: application/json" \
  -d '{"query": "{ books { id title author publishedYear } }"}'

Testing the API

You can test the API using tools like:

• GraphQL Playground: Open http://localhost:8080/graphql and interact with the API via a GraphQL Playground interface.
• Postman: Create a POST request to http://localhost:8080/graphql with the GraphQL query as the body.

Code Structure

• main.go: The main entry point for the application, where the server is initialized and GraphQL schema is defined.
• books: A mock list of books used for querying and mutation.
• graphql-go: The package used for defining GraphQL types, queries, mutations, and executing the queries.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Feel free to fork this repository and create pull requests. Contributions are welcome!

For more information on GraphQL, you can visit the official GraphQL website.